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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
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Wreckage of New York World Trade Center, February 1993. Reprinted, by permission, from Archive Photos (Reuters/Mike Segar). Copyright by Archive Photos.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

5
Limiting Criminal Access to Explosives and Precursor Chemicals

INTRODUCTION

Given the many types and sources of explosives and precursor chemicals1 for use in constructing bombs, it seems impossible to prevent all illegal bombings by controlling bombers' access2 to these materials. More realistic are controls that could make it more difficult for would-be bombers to carry out their crimes and could increase the probability of their being caught—an approach taken by the British and others in their efforts to thwart terrorist bombers.

In weighing the possible costs and benefits of legislative controls on access to precursor chemicals, the committee concluded that there would be no substantial benefit to law enforcement if only precursor chemicals were regulated without also imposing adequate controls on criminal access to the commercial explosives themselves. Because access in the United States to commercial explosives may not be adequately regulated at the federal level, assessment of the need for controls must extend to all precursors to illegal explosions. This broader set of precursors includes precursor chemicals, as well as commercial explosives and detonators that are commonly available to would-be bombers by legal and illegal means.3

1  

 In this context, a precursor chemical is any chemical that can be used to manufacture an explosive material.

2  

 As used here, the term ''access" includes legal purchase, fraudulent purchase, and theft.

3  

 Black and smokeless powders, which were excluded from the charge for this study, are currently used in about one-third of all bombing incidents (FBI, 1997). Options for controlling black and smokeless powders will be discussed in a National Research Council report forthcoming in October 1998.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

The appropriateness of any regime for controlling explosives and precursor chemicals must be judged in the context of the perceived bombing threat. Control measures whose costs appear to outweigh their benefits in periods when major bombings are infrequent may appear more attractive if major bombings become more frequent. Therefore, the committee structured its discussion of controls to include a range of graduated options that may be appropriate for containing a bombing threat in the United States at current, increased, and greatly increased levels.

CONTROLS ON PURCHASE AND USE OF COMMERCIAL EXPLOSIVES IN THE UNITED STATES AND ABROAD

Current U.S. Regulations Controlling Access to Explosives

At the federal level, explosives currently are controlled under Title XI of the Organized Crime Control Act of 1970.4 Additional requirements may be imposed at the state and local levels.

The central feature of the existing federal regime is that it requires a license for engaging in the interstate manufacture, importation, or distribution of explosive materials and a permit for the interstate transportation of such materials for one's own use. The explosive materials subject to the federal explosives law are listed annually by the Bureau of Alcohol, Tobacco, and Firearms (ATF) (Federal Register, 1997). The list, which includes commercial and military explosives, black and smokeless powders above a minimum quantity, pyrotechnic compositions and special fireworks, many explosive chemicals, detonators and blasting caps, propellants, ammonium nitrate explosive mixtures, and urea nitrate, is quite comprehensive for materials that are themselves explosive. It does not include nonexplosive precursor chemicals or pure ammonium nitrate.5

Applicants for a federal license or permit (ATF Form 5400.13/5400.16) must show "competence" to handle explosives by demonstrating adequate storage facilities for explosive materials, if storage is required; familiarity with relevant state and local laws; and compliance with the Federal Water Pollution Control Act. Applicants for licenses and permits must also certify that they meet certain "good character" requirements.6 The ATF conducts routine criminal background checks before issuing a license or permit; extensive background checks are rarely done.

4  

 See "Regulation of Explosives," Title 18, United States Code, Chapter 40. The implementing rules and regulations are detailed in Title 27, Code of Federal Regulations, Part 55, "Commerce in Explosives."

5  

 In addition, the ATF lists a large number of explosive materials that are seldom if ever used.

6  

 Applicants must certify that they are over 21 years old, have not willfully violated the federal explosives law and its requirements, and have not knowingly withheld or falsified information on the application.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

Intrastate commerce and commerce between contiguous states that by mutual agreement allow shipments across their adjoining borders do not require federal permits or licenses. Although both types of (effectively intrastate) transactions do require that purchasers produce positive identification (such as a driver's license) and fill out a form—ATF Form 5400.4—certifying that they meet "good character" requirements,7 the completed form is retained by the seller, and the ATF is not informed of the transaction at the time of sale.8

The Institute of Makers of Explosives surveyed member companies to determine the number of ATF Form 5400.4 (intrastate) transactions made during calendar year 1993 and the quantity of explosives purchased. The responding companies reported that more than 47,000 separate ATF Form 5400.4 transactions took place, more than 455 million pounds of explosives were purchased, and well over 1 million detonators were included in the explosive materials purchased.9 The opportunity for illicit activity is clearly significant.

The committee found that current federal requirements for purchasing explosives are so easily met or circumvented that federal law is largely ineffective in keeping explosives out of the hands of criminals. Thus, the United States is dependent on state laws and regulations for controlling the purchase and storage of explosives. Unfortunately there is a lack of uniformity among these laws, which range from very restrictive purchasing requirements to essentially none.

For example, in 1995, according to one analysis, fewer than half of the states (21) required a license or permit for all purchases of explosives (Hoover, 1995). Fourteen required a license or permit for some uses of explosives, and 17 states had no statutes dealing with the purchase of explosives. Only two states required a waiting period before a license or permit could be issued.

The divergent approach to regulation taken in California and Utah illustrate the wide state-to-state variation in laws governing the purchase of explosives. On the one hand,

[t]he State of California has one of the strictest explosives control laws in the United States. It requires a permit to manufacture, distribute, receive or possess, transport, or use explosives; to operate a terminal for handling explosives; or to park or leave standing any vehicle carrying explosives. In addition, the

7  

 Distribution is prohibited to anyone who is under 21 years old; has been convicted of a felony involving more than 1 year of imprisonment; is currently under indictment for a felony; is a fugitive from justice; is an unlawful user of, or is addicted to, certain defined controlled substances; or has been legally judged to be mentally incompetent.

8  

 However, the forms are available for review by the ATF during annual inspections of licensees and permittees and for use in investigations involving use of explosives (Gail Davis, ATF, personal communication, February 20, 1998).

9  

 Frederick P. Smith, then president of the Institute of Makers of Explosives, to John W. Magaw, director of ATF, in a letter dated February 24, 1994.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

State requires a one week delay in the issuance of a permit, except in the case of an emergency. In order to qualify for a permit the applicant must have sufficient and adequate facilities to engage in the activities specified in the application. The application can be denied if the issuing authority finds that the handling or use of explosives by the applicant would be hazardous to property or dangerous to any person. Once issued a permit is valid only for the time when the activity authorized by the permit is performed and not longer than one year. The state Fire Marshall is authorized to enforce the statutory requirements. (Hoover, 1995)

On the other, the State of Utah in 1995 had no state requirements defined by statute as applying to the purchase of explosives (Hoover, 1995). Counties were authorized to regulate the storage of explosives.

Regulation of Explosives in Other Countries

Members of the committee visited Switzerland and Great Britain to hear firsthand how both regulate explosives (see Appendix F). These countries were selected because of their well-known actions to thwart terrorism in recent years. Additional information provided by one committee member was also thought to be of value because it describes experiences in countries with adjacency to the United States (Canada), large size and relative freedom from terrorist activities (Australia), and severe threat (Northern Ireland, Great Britain, and Israel).

Switzerland10

In Switzerland, the Federal Ministry of Education provides training courses that a person seeking to buy explosives must pay for and complete in order to obtain a lifetime license. The licenses are administered by the cantons (states), which require a name and signature upon purchase. To buy explosives, the purchaser must take the license and a purchase order to the canton police, who verify the license and approve the application. The vendor requires a name and signature and keeps records for 5 years. No background checks are made. The law also requires safe storage.

One effect of this legislation has been to drive individual users of explosives from the market (perhaps owing to added burdens of time and expense), leaving the market to commercial blasters. The implementation of these regulations in 1980 coincides with a significant drop in bombing incidents.

10  

 This section is based on a personal communication from Kurt Zollinger, Scientific Research Service, Zurich Stadtpolizei, April 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
Canada11

The Canadian federal Explosives Act12 and related regulations13 control the manufacture, purchase, use, transportation, and storage of explosives throughout Canada, except for use and storage at mines and quarries, which fall under provincial jurisdiction. Provinces and municipalities are bound by the act but may pass additional regulations to suit regional needs, including regulations that may apply to transportation.

Under the federal act, licensed vendors may issue a permit for purchase and possession of explosives and sell up to 75 kg of high explosives and 100 detonators to a person over 18 years of age who presents appropriate identification. If the purchaser is known to the vendor, there is no police involvement. Otherwise, the purchaser's identification and residential address must be confirmed by the police. No background checks are conducted. The purchaser must sign and print his name, present identification, and indicate details of use, storage, and transportation. The explosives must all be disposed of within 90 days.

A purchaser who wishes to buy and store more than 75 kg of explosives must apply to the Department of Energy, Mines, and Resources for a 1-year license. The entire process can be accomplished by mail or fax. Copies of the license are forwarded to the police department with jurisdiction in the area where the magazine is located. The process for obtaining a license involves no purchase limits or training requirements, and no background checks for a criminal record are conducted.

Thus, federal law governs most aspects of the sale and custody of explosives in Canada, although the exemption for mines and quarries leaves a large gap in federal control. No background checks are conducted of licensed magazine owners, blasters, truck drivers, or anyone else with access to explosives.

Australia14

In Australia, which has been relatively free of terrorist activity, a purchaser must have a license or permit, must sign sales documents, and in some states must sign a register and produce identification. However, there is no direct federal government involvement. There is also no police involvement in license acquisition, since it falls under the dangerous goods legislation in each state. However,

11  

 This section is based on a personal communication from John Martin, explosives inspector, Department of Energy, Mines, and Resources, Vancouver, B.C., Canada, June 1997.

12  

 Explosives Act, R.S.C. 1985, c.E-17; S.C. 1993, c.32, s.3; S.C. 1995, c.35, s.2.

13  

 For example, Motor Vehicles Act, R.S.B.C. 1996, c.318, s.206; Vancouver Charter, S.B.C. 1953, c.55, s.311.

14  

 This section is based on a personal communication from Carl Christie, director, Australian Bomb Data Centre, Canberra, Australia, July 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

permits for use of small quantities of explosives may be issued by a police officer of sergeant rank.

Great Britain15

In Great Britain (Scotland, England, Wales), manufacturing and storage of explosives are regulated by the Explosives Act (1875). The transfer of explosives falls under the Policy on Marketing and Supervision of Transportation of Explosives Regulations (1973),16 and acquisition by persons is covered under the Control of Explosives Regulations (1991).17 A person who wishes to purchase explosives must apply to the police for a certificate to acquire and keep them. The first criterion is that a prospective purchaser must have a safe and secure place to store the explosives. Security requirements on magazines are high: either a magazine must have an alarm system that will operate if a break-in occurs, or the area must be patrolled regularly. If this criterion is satisfied, the police then conduct a background check on the applicant, including a criminal record check. If a prospective purchaser is a prohibited person under the Control of Explosives Regulations, then a license is denied. The current status and nature of a criminal conviction are considered, but for anyone previously convicted of an offense under the Explosives Substances Act, a certificate is not issued. Otherwise, a license valid for up to 3 years may be issued to acquire and keep explosives. There are no controls on the purchase of ammonium nitrate fertilizer, because it is not classified as an explosive.

By contrast, in the United States, individuals can be licensed in many states without a background check or any police involvement. Also, requirements for magazine security are more stringent in Great Britain than in the United States, where security relies more on magazines meeting manufacturing specifications and being in remote locations. The much tighter controls in Great Britain ensure that there are few incidents involving commercial high explosives.

Northern Ireland18

In Northern Ireland, explosives are controlled under the Explosives (Northern Ireland) Order of 1972 and related legislation, and the police are involved at

15  

 This section is based on a personal communication from John Phillips, Explosives Policy Section, Health and Safety Executive, London, England, June 1997.

16  

 Legislation passed in compliance with European Economic Community Council Directive 93-15 EEC 5, April 1995 ("Civil Uses Directive").

17  

 Regulations made under the Health and Safety at Work Act (1974).

18  

 This section is based on a personal communication from Gerard Murray, Forensic Science Agency of Northern Ireland, Belfast, Northern Ireland, March 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

all stages in the acquisition, transportation, and use of commercial explosives. A prospective purchaser must first apply for a license to the police, who assess the request and conduct a background check before issuing a license for purchase of a specific quantity. Police escort explosives transported from the manufacturer to a central magazine, which is protected by armed guards and, on purchase, from the magazine to the user. The police observe the use of legally purchased explosives and ensure that all explosives are used or destroyed. In fact, individuals cannot obtain a license to purchase explosives—essentially, they must contract with a licensed commercial blaster. As a consequence, commercial high explosives used in criminal bombings in Northern Ireland typically are smuggled into the country.

The tight controls on the sale, storage, and transportation of commercial explosives in Northern Ireland contrast with the approach taken in the United States, as do the nature and extent in the two countries of the threat of domestic terrorist violence using explosives.

Israel19

In Israel, controls on the purchase of explosives are so tight that there are virtually no cases of criminal bombings involving commercial high explosives. Bombing incidents generally involve either improvised explosives or high explosives designed for military use that are stolen or smuggled into the country.

Adopting Uniform National Regulations for the Purchase of High Explosives in the United States

In general, the lessons learned from other countries' laws and procedures for domestic use of explosives are straightforward: typically the laws derive directly from the level of threat experienced, and so the higher the threat, the tighter and (in most cases) the more costly and inconvenient the controls. Northern Ireland, Great Britain, and Israel, all of which have a high threat level, have made commercial explosives less accessible to terrorists, who must then improvise, steal, or otherwise obtain these materials from out-of-country sources. In contrast, Canada and the United States control explosives to varying degrees at the federal level, but such control may be compromised by exceptions to federal jurisdiction.

The committee concluded that a criminal in the United States can easily purchase explosives in a state with few requirements and then use them anywhere in the United States. Therefore, the committee recommends that uniform national regulations for the purchase of commercial high explosives be developed

19  

 This section is based on a personal communication from Shmuel Zitrin, Israel National Police, Jerusalem, Israel, June 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

and implemented. These regulations should apply to both intra-and interstate distribution of explosives.

The committee makes no recommendation as to whether states should remain free to impose controls stricter than the federal ones. It does urge, however, that consideration be given to ways to minimize the additional costs to industry, if any, if controls are imposed. Federal preemption of state laws governing purchase of explosives (creating a single, uniform federal system) might be one way to achieve cost minimization. The committee's recommendation for uniform national regulations for the purchase of explosives is not unique. For instance, the Institute of Makers of Explosives has supported a national licensing program for many years (see Box 5.1).

At a minimum, the recommended uniform national regulations would extend current interstate controls (i.e., federal requirements for licensing and for verification

BOX 5.1 Related Proposals for Control of Explosives

The Institute of Makers of Explosives has proposed a national licensing program that would do the following:1

  • Eliminate ATF Form 5400.4 transactions;

  • Require that an individual possess a federal license or permit before being able to purchase detonators, high explosives, and blasting agents;

  • Exempt black and smokeless powders;

  • Exempt only law enforcement agencies;

  • Establish a license or permit fee to cover only costs associated with the licensing process;

  • Prohibit existing local, county, or state requirements from supplementing federal license requirements. These requirements would be in addition to federal requirements; and

  • Establish safeguards (e.g., fingerprinting, a medical examination) in the application process to make approval of false information difficult.

In addition, several bills introduced in the Congress have sought to create a federal licensing scheme that would cover intrastate transactions, including some requiring the photographing and fingerprinting of applicants, or instant background checks.2

1  

Frederick P. Smith, president of IME, to John W. Magaw, director of ATF, in a letter dated February 24, 1994.

2  

See, for instance, the Restricted Explosives Control Act (H.R. 488), introduced in the 104th Congress, first session, on January 11, 1995, which requires a federal permit for intrastate purchase of explosives, as well as photographing and fingerprinting; and the Bombing Prevention Act (H.R. 4828), introduced in the 103rd Congress, second session, on July 25, 1994, which had similar provisions and required background checks.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

of compliance with storage requirements) to cover intrastate transactions involving explosives. These uniform national regulations would add significantly to the expenses of individuals seeking to purchase explosives, particularly in those states that currently have few controls. Such prospective purchasers would face the additional time and effort of applying for a license and would have to demonstrate that the explosives would be transported in an approved manner and stored in an approved magazine. Costs to state law enforcement agencies and the ATF would also rise for the processing of license and permit applications, and for the investigation of applicants and inspection of their magazines. Presumably, these additional program costs would be offset wholly or partially by fees paid by the applicants. Coordination among state and federal regulatory programs would become critical to minimize overall costs and would help ensure effective enforcement and minimize duplication of effort.

Uniform national regulations might well change some of the economics of explosives use in the United States. For example, to avoid increased costs, individuals might have to hire blasting companies to perform work that they formerly did themselves.20 Such a change would likely be opposed by farmers and other individuals who have legitimate uses—such as the removal of tree stumps—for explosives that would be regulated.

Limiting the Theft of Explosives

At least for preventing illegal bombings, the benefits of uniform national purchasing regulations and a licensing program for explosives are limited to the extent that would-be bombers can continue to obtain explosives by theft. In 1995, the most recent year for which statistics were available, 3,404 pounds of packaged high explosives and 5,300 pounds of blasting agents were reported stolen (ATF, 1997). However, these figures probably understate the actual amount stolen: In 1995, for instance, 7,731 pounds of packaged high explosives and 8,031 pounds of blasting agents were recovered by authorities, in both cases considerably more than the amounts reported stolen.

Experts contacted by the committee believe that in most cases, the high explosives used in bombings are stolen.21 Commercial explosives are particularly attractive as initiators and boosters for improvised bombs such as the one that produced such devastating effects at the Murrah Federal Building in Oklahoma City.22

20  

 Such a change occurred in both Switzerland and Northern Ireland under similar conditions, as indicated in the section titled "Regulation of Explosives in Other Countries."

21  

 J. Christopher Ronay, president of the Institute of Makers of Explosives, and Kevin Stadnyk, former federal explosives inspector, British Columbia, Canada, personal communications, June 1997.

22  

 Evidence presented at the trial of Timothy McVeigh, convicted of the bombing, linked him to a break-in at a Kansas magazine in which a variety of high explosives and detonators were stolen.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

The most common sources of stolen explosives are believed to be remotely located magazines maintained by end users (ATF, 1997).23 Under current law, these are required to be monitored only once per week and so offer an inviting target for thieves.24 In addition to theft from magazines, an unknown amount is stolen from end users such as farmers who may store the explosives in an unsecured facility such as a barn. Such thefts may go unreported, since the victim would have to acknowledge that the explosives were not stored in an approved magazine, as required by law.

The committee recommends, in conjunction with its recommendation for uniform national regulations governing the purchase of explosives, that the Bureau of Alcohol, Tobacco, and Firearms be given the authority and resources to ensure that all purchasers of high explosives use secure magazines if the explosives are to be stored. This precaution would sharply reduce the number of opportunities for would-be bombers to steal explosives from unsecured storage facilities.

COMMON PRECURSOR CHEMICALS POTENTIALLY SUBJECT TO CONTROLS-DEVELOPING A SHORT LIST

Chemical Precursors to Explosives

A very large number of precursor chemicals that can be used to make effective bombs are not listed explicitly by the ATF as explosive materials and so are not currently controlled as explosives under federal law (Federal Register, 1997). To define which of these should be considered for controls, the committee compiled a relatively long list of common precursor chemicals and then applied defined criteria to produce a "short list" of precursor chemicals that appear to pose the greatest risks in terms of their potential for use in bomb making.25 The committee considered three kinds of chemical precursors to explosives: those that are explosive on their own, those that can be physically mixed to produce

23  

 Magazines may be owned by manufacturers, dealers, permittees, and users. Over the past 5 years, an average of 47 percent of reported thefts of explosives occurred from end-user magazines.

24  

 There are an estimated 40,000 magazines in the United States (Tom Dowling, Institute of Makers of Explosives, personal communication, June 1997).

25  

 The committee's various sources included a review of chemicals recommended in written material, and at various sites on the Internet, for constructing homemade bombs; information on chemicals regulated in Northern Ireland; and the committee's own experience and expertise in the area. For examples of written material, see, Powell, W., "The Anarchist Cookbook," Lyle Stuart Inc., Secaucus, N.J., 1971; Lecker, S., "Homemade Semtex, C-4's Ugly Sister," Paladin Press, Boulder, Colo., 1991; Galt, J., "The Big Bang: Improvised PETN & Mercury Fulminate," Paladin Press, Boulder, Colo., 1987; and Benson, R., "Homemade C-4: A Recipe for Survival,'' Paladin Press, Boulder, Colo., 1990.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

explosives, and those that are individually harmless26 but can be reacted to produce an explosive material. These are discussed separately below.27

Precursors That Are Explosive on Their Own

The chemicals listed below are detonable under some conditions in pure form and may also be mixed with other chemicals to produce effective explosives:

  • Ammonium nitrate,

  • Dinitrotoluene,

  • Nitromethane, and

  • Picric acid.

Precursors That Can Be Physically Mixed to Produce Explosives

Most military explosives contain both the oxidizer (oxygen atoms) and the fuel (usually carbon and hydrogen atoms) in the same molecule. However, under certain conditions some oxidizing chemicals can be physically mixed with fuels to produce an explosive composition.

Oxidizers

Effective oxidizers are salts of certain oxygen-containing anions. Often the accompanying cations are inconsequential and interchangeable; those typically combined with these anions are given in parentheses in the following list of common oxidizers:

  • Chlorates (sodium, potassium, etc.),

  • Chlorites (sodium, etc.),

  • Hypochlorites (sodium, calcium, etc.),

  • Nitrates (sodium, potassium, ammonium, etc.),

  • Nitrites (sodium, etc.),

  • Perchlorates (potassium, etc.), and

  • Permanganates (potassium, etc.).

26  

 Such precursors are harmless as explosives but nevertheless may be toxic, corrosive, or otherwise hazardous.

27  

 See Encyclopedia of Explosives and Related Items (1960-1983) for information on the chemicals listed in the accompanying subsections.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
Fuels

Many fuels could be used with the oxidizers listed above, but those listed below provide extra energy and/or produce hot gases that expand rapidly to create the explosive effect:

  • Aluminum powder,

  • Carbon-rich fuels (charcoal, sugar, fuel oil, etc.),

  • Magnesium powder,

  • Nitrobenzene,

  • Phosphorus,

  • Sulfur, and

  • Zinc powder.

Precursors That Must Be Reacted Chemically to Produce Explosives

In principle, of course, given the proper expertise and equipment, it would be possible to synthesize explosive compounds from many starting materials. For example, one recipe offered on the Internet describes the synthesis of picric acid from common aspirin. However, the committee lists below only precursors that can be reacted to produce explosive compounds in one or perhaps two relatively simple steps:

  • Acetone,

  • Ammonia,

  • Cellulose,

  • Ethylene glycol,

  • Glycerine,

  • Hexamine,

  • Hydrogen peroxide (concentrated),28

  • Nitric acid (concentrated),29 and

  • Urea.

28  

 Hydrogen peroxide is sold in aqueous solutions at concentrations of 3 to 70 percent. Before any specific regulations were developed, it would be advisable to obtain additional input from concerned manufacturers and distributors.

29  

 The azeotropic material obtained by distillation of aqueous nitric acid is 68 percent nitric acid. Nitration of organic materials usually employs acid of at least this concentration, but conditions vary widely according to the specific reaction involved. Before any specific regulations were developed, it would be advisable to obtain additional input from concerned manufacturers and distributors. "Mixed acid" (nitrating acid), a commercial product consisting of a mixture of sulfuric acid and concentrated (98 percent) nitric acid, should also be covered by any regulation of nitricacid.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

Criteria for Generating a Short List of Precursor Chemicals That Are Candidates for Controls

The picture that emerges from the bombing statistics discussed in Chapter 1 is one of a large number of small bombs (about 2,000 annually) that cause relatively little damage (about $8 million annually), occasionally punctuated by a large-scale bombing that galvanizes public concern. In addition to considering the chemicals used most often in bombings, the committee believed that it was of equal or even greater importance to focus on the bombings that have led to the most serious consequences. This is not to belittle the effects of the considerable number of smaller bombs used, but rather to emphasize that in terms of casualties, physical damage, and public perception of vulnerability, the large-scale bombs require more concentrated preventive effort. Accordingly, the committee used the following three criteria for selecting the explosive precursor chemicals that may pose the greatest risks:

  1. The chemical should be reasonably adaptable (and available or accessible in amounts on the order of 100 pounds or more of explosive material) for use in making large bombs. Although 100 pounds is a somewhat arbitrary mass, this criterion reflects the fact that the chemical must be available to the public in sufficient quantity that with a reasonably limited number of purchases, an individual could construct a significantly destructive bomb at a cost that would not be excessive.

  2. The chemical should be an essential component in an explosive system either in significant use, or with a potential for significant use as measured in terms of deaths, injury, and property damage. The committee considered chemicals used in foreign bombings as well as those used in the United States.

  3. The chemical should be a critical precursor, i.e., one not easily replaced in generating the explosive system. For example, a number of chemical fuels may be substituted for diesel fuel oil in ammonium nitrate/fuel oil (ANFO) explosives, but the ammonium nitrate is critical. This criterion derives directly from information received by the committee in interviews with British authorities who found that terrorist bombers quickly moved to substitutes for precursors once the original ones had been made difficult to obtain.

Application of the Criteria to Common Precursor Chemicals

Table 5.1 shows the results of applying the three criteria above to common precursor chemicals of the three types considered by the committee. Presenting the highest risk of use are two chemicals that received a "yes" for clearly meeting each of the three criteria applied to identify high-risk precursors: ammonium nitrate and urea. Of all the chemicals, ammonium nitrate clearly poses the greatest risk, owing to its wide availability, low cost, and ease of use in bomb making

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

TABLE 5.1 Results of Applying Selection Criteria to Identify Precursor Chemicals Likely to be Used in Bomb Making

Chemical Type

Availability/Accessibility for Use in Large Bombs

Significant Use or Potential for Use

Identified as a Critical Component

Explosive Chemicals

 

 

 

Ammonium nitrate

Yes

Yes

Yes

Dinitrotoluene

No

No

Yes

Nitromethane

Yes

Some

Yes

Picric acid

No

No

Yes

Precursors That Can Be

 

 

 

Physically Mixed Oxidizers

 

 

 

Potassium chlorate

Some

Yes

Yes

Sodium chlorate

Some

Yes

Yes

Sodium chlorite

No

No

Yes

Calcium hypochlorite

Yes

No

Yes

Potassium nitrate

Yes

Somea

Yes

Sodium nitrate

Yes

Somea

Yes

Sodium nitrite

No

No

Yes

Potassium perchlorate

Some

Yes

Yes

Potassium permanganate

No

No

Yes

Fuels

 

 

 

Aluminum powder

Yes

Yes

No

Carbon-rich fuels

Yes

Yes

No

Magnesium powder

No

No

No

Nitrobenzene

Yes

Yes

No

Phosphorus

No

No

No

Sulfur

Yes

Yes

No

Zinc powder

No

No

No

Precursors Requiring

 

 

 

Chemical Reactions

 

 

 

Acetone

Yes

Some

Yes

Ammonia

Yes

No

Yes

Cellulose

Yes

No

No

Ethylene glycol

Yes

No

Yes

Glycerine

Yes

No

Yes

Hexamine

No

No

Yes

Hydrogen peroxide (concentrated)

Some

Some

Yes

Nitric acid (concentrated)

Some

Yes

Yes

Urea

Yes

Yes

Yes

NOTE: The qualitative results expressed are based on testimony of Richard Strobel, ATF, before the committee, March 24, 1997, subsequent personal communications from Richard Strobel, and the committee's judgment.

a Although sodium nitrate has not been seen as often as potassium nitrate in improvised explosives, it is a common ingredient (often in combination with ammonium nitrate) in commercial explosives and is therefore considered to have the potential for significant use.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

(see also Table 4.2). Urea, a precursor chemical that can be reacted with nitric acid to produce the explosive urea nitrate, is not considered a major threat if appropriate steps are taken to control nitric acid (see below).

In the second category are chemicals that do not clearly meet all three criteria but could conceivably be used by sophisticated and dedicated bombers to make large bombs and so did not receive any "no's" (see Table 5.1): nitromethane, sodium nitrate and potassium nitrate, sodium chlorate and potassium chlorate, potassium perchlorate, acetone, hydrogen peroxide (concentrated), and nitric acid (concentrated). Acetone, a precursor chemical that can be reacted with hydrogen peroxide to produce the explosive triacetone triperoxide (TATP), is not considered a threat if appropriate steps are taken to control hydrogen peroxide (see below).

In the third category are chemicals that fail to meet at least one of the committee's criteria for potential as a high-risk material and so received at least one "no" (see Table 5.1). These chemicals are excluded from further consideration in this report. It should be noted that chemicals such as sodium chlorite and sodium nitrite are controlled in Northern Ireland (see below), but because they have not caused significant casualties or property damage in the United States, the committee simply takes note of them for future consideration.

Combining the two sets of higher-risk chemicals yields the committee's "short list" of candidate precursor chemicals for possible controls, given in Table 5.2. The three criteria outlined—availability and accessibility, significant use, and essential nature—were used to gauge the degree of risk posed by the precursor chemicals, rather than the cost or feasibility of controlling access to them. Many of these precursor chemicals have abundant applications and uses that are legal and unrelated to explosives. To minimize the inconvenience and cost to legal users, the committee believes that every effort should be made to avoid

TABLE 5.2 Short List of Explosive Precursors Most Likely to Be Used in Bomb Making

Type

Precursors

Explosive chemicals

Ammonium nitrate

 

Nitromethane

Oxidizers

Sodium nitrate, potassium nitrate

 

Sodium chlorate, potassium chlorate

 

Potassium perchlorate

Fuels

None

Reactant chemicals

Acetone

 

Hydrogen peroxide (concentrated)

 

Nitric acid (concentrated)

 

Urea

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

unnecessary controls on chemicals that are widely used for legitimate purposes. However, depending on the level of bombing threat posed and the need to facilitate enforcement, controls may be desirable even if they do involve high cost and inconvenience. The committee discusses the economic implications of controls on access to the short-list precursor chemicals in the section below titled "Costs and Benefits of Recommended Controls."

POTENTIAL MODELS FOR CONTROL OF EXPLOSIVES PRECURSORS

In considering ways in which explosives or their precursors might be more effectively controlled, the committee received briefings on both the Chemical Diversion and Trafficking Act and the Chemical Weapons Convention.30

Chemical Diversion and Trafficking Act31

The purpose of the Chemical Diversion and Trafficking Act (CDTA) is to regulate both "precursor" and "essential" chemicals that are needed for the manufacture of illicit drugs. Controlling the diversion of such chemicals from lawful commerce is an important element of the national strategy to control the illicit drug industry.

A "precursor" chemical in the context of CDTA is used in the manufacture of a controlled substance and actually becomes part of the controlled substance's molecular structure. "Essential" chemicals include reagents and catalysts used in the manufacture of a controlled substance. Although they are necessary for the manufacturing process, they do not become part of the controlled substance's molecular structure.

The CDTA of 1988 gives the Drug Enforcement Agency (DEA) the authority to regulate domestic sales as well as the import and export of precursor and essential chemicals necessary for producing cocaine, heroin, methamphetamine, LSD, and other illicit drugs. The act also regulates the sale of machinery and equipment required in drug manufacture, such as tableting and encapsulating machines, flasks, and laboratory heaters.

All who handle the chemicals (including manufacturers, distributors, importers, and exporters) must maintain records of any transaction involving a listed chemical that exceeds an established threshold amount. These records must be

30  

 On CDTA: testimony to the committee by John Moudri, Drug Enforcement Administration, May 3, 1997; on CWC: testimony to the committee by Will Carpenter, consultant, and Robert Mikulak, U.S. Arms Control and Disarmament Agency, May 3, 1997.

31  

 Chemical Diversion and Trafficking Act, Subtitle A of the Anti-Drug Amendments of 1988 (Title VI of Public Law 100-670). This section is based on material in U.S. Department of Justice (1993), p. 21.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

maintained in a form that is retrievable by the DEA. Handlers must also obtain proof of identity from all purchasers of listed chemicals and must notify the DEA of any unusual or suspicious orders. For international shipments, the DEA must be notified at least 15 days prior to shipment for any shipment over the threshold amount. The act also requires that exporters and importers of listed chemicals report the transaction by submitting the Import/Export Declaration form, which requests information on quantities shipped, receiving company name, and so on.

The CDTA originally identified 20 precursor and essential chemicals to be regulated. The 1990 amendments to the CDTA added 11 chemicals, and the DEA also has added 2 more chemicals by administrative action. Thus, the United States now regulates a total of 33 precursor and essential chemicals needed for the manufacture of illicit drugs. These chemicals are arranged on two lists. Transactions involving the more "critical" List I chemicals (primarily precursors as defined above) are controlled at much lower thresholds than those involving List II chemicals (primarily solvents and reagents). Further details on record keeping and reporting requirements are given in Box 5.2.

The Chemical Manufacturers Association (CMA) advised the committee that, as reported by the Office of Management and Budget (OMB), 3,800 reports were made to the DEA under the CDTA in 1996,32 including 1,800 import/export declarations and 2,000 suspicious order reports. The OMB estimated that these reports required about 50,000 hours to complete. The CMA used a standard wage rate estimate of $50/hour to calculate an overall annual cost of about $2.5 million.

The Chemical Weapons Convention

The Chemical Weapons Convention (CWC), which entered into force in the United States on April 29, 1997, bans the development, production, possession, stockpiling, transfer, and use of chemical weapons (OTA, 1993). After ratification, the participating states have 10 years to destroy their existing stockpiles of chemical weapons and associated production facilities. The CWC differs from previous arms-control treaties in the magnitude of its effects on private industry, including extensive reporting requirements and on-site inspections of commercial chemical plants. Those inspections will be carried out by multinational teams that will include inspectors from political adversaries and economic competitors of the United States.

The CWC bans any toxic chemical agent, regardless of origin, that interferes with life processes and does not have legitimate civil applications in the quantities in which it is produced. This so-called "general-purpose criterion" allows the

32  

 Jeffrey C. Terry, Chemical Manufacturers Association, testimony to the committee, March 3, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

BOX 5.2 Chemical Diversion and Trafficking Act Record Keeping and Reporting Requirements

Record Keeping

The Chemical Diversion and Trafficking Act has several record-keeping requirements for manufacturers and distributors of precursor and essential chemicals. All records of transactions must be maintained for 4 years following the transaction date for precursor chemicals and for 2 years for essential chemicals. Records of the sale of tableting and other laboratory equipment must also be kept for 4 years.

Records of each transaction must include the following: the names and addresses of the buyer and seller; the date of the transaction; the name, quantity, and form of packaging for the substance in question; the method of transportation used to transfer the substance; and the type of identification provided by the purchaser and its unique identifying number.

Operators may use their normal business records for these purposes, as long as the information contained above is included and is retrievable for Drug Enforcement Agency (DEA) investigations.

Reporting to the Drug Enforcement Agency

In certain circumstances, operators must make special oral reports to the DEA division office in the area where the operator does business. These circumstances are as follows:

  • Any transaction involving a large quantity of the chemical, an uncommon method of payment, an unusual method of delivery, or any situation that causes the supplier to believe that the chemical might be used for an illegitimate purpose;

  • Any transaction that involves a person whose description or identifying characteristics have been provided to the operator by the DEA;

  • Any unusual or excessive loss or disappearance of a listed chemical; or

  • Any domestic transaction involving a tableting or encapsulating machine.

Reports involving suspicious orders should be made when a customer pays in cash or another unusual manner, fails to provide adequate information about his or her business and the purpose of the chemical purchase, or otherwise is evasive or nonresponsive regarding the purchase.

Reports to the DEA regarding suspicious transactions or other suspicious

treaty to apply to all conceivable chemical warfare agents, including production of novel chemicals that might be developed in the future, even if they are not now listed in the treaty. Furthermore, the CWC bans or controls certain intermediate compounds or precursors that can be converted to chemical warfare agents in one or a few steps in a reaction.

Chemicals that are explicitly covered by the CWC range from actual chemical

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

circumstances must be made at the earliest practical opportunity. The oral report must be followed by a written report to the same DEA division office, and must include the following information:

  • The name, address, and telephone number of each party, if available;

  • The date of the intended transaction;

  • The name, quantity, description, and form of packaging of each chemical or machine;

  • The method of transfer (truck, delivery, etc.);

  • The type of identification used by the customer and any unique identifying number; and

  • Special circumstances that caused the operator to report the suspicious order.

If the report is for loss or theft of a listed chemical, the report should contain the date, the type of chemical missing, and a description of the circumstances.

Proof of Identity

All transactions involving these chemicals require proof of identity. For companies, proof of identity requires the supplier to check the customer's documentation (business stationery, order forms, and so on) and then to validate that the customer is a legitimate company by checking local directories, credit bureaus, chambers of commerce, and other reliable sources. Customers that cannot be validated are to be reported to the DEA.

For new customers, operators must also establish the company's authorized purchasing agents in order to prevent fraudulent purchases by unauthorized employees. For each customer, the operator must keep on file the names and signatures of authorized purchasing agents and any electronic passwords or other encoding methods used by the customer to ensure the authenticity of the purchaser. This list of purchasing agents is required by law to be updated annually.

Any domestic transaction by an individual must also be accompanied by the purchaser's signature, driver's license, or other legitimate identification. The DEA suggests that any purchase by an individual with cash is by nature suspicious.

SOURCE: Chemical Diversion and Trafficking Act, Subtitle A of the Anti-Drug Abuse Amendments of 1988 (Title VI of Public Law 100-670). This section is based on materials in U.S. Department of Justice (1993), p. 21.

warfare agents to key final-stage precursors and more distant precursors. Depending on their utility for producing chemical weapons and the extent to which they have legitimate commercial uses, these compounds or groups of compounds are categorized into three schedules. Each schedule is associated with a different set of reporting requirements and inspections, with the most hazardous compounds being subject to the most stringent controls. A fourth

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

BOX 5.3 Chemical Weapons Convention Categories

Schedule 1

Schedule 1 of the Chemical Weapons Convention covers 12 toxic chemicals or groups of chemicals that have no or low commercial use. These compounds include standard chemical warfare agents and key final-stage precursors used in binary chemical weapons. Although large-scale production of Schedule 1 chemicals is banned, each country may maintain a total of 1 metric ton for medical or research purposes.

Annual facility reports are required at a production threshold of only 100 g. Those reports must cover production, acquisition, processing, consumption, and import/export data for the previous calendar year, and anticipated data for the next year. An initial baseline inspection of the facility is mandatory, with the number of annual routine inspections based on the characteristics of the facility. There is a production threshold of 10 kg for inspections.

Only a few pharmaceutical companies that produce toxic anticancer drugs are likely to be affected by Schedule 1.

Schedule 2

Schedule 2 covers 14 chemicals or groups of chemicals. The list includes three chemicals with warfare potential that have never been used in combat and several precursor chemicals that are one or more reaction steps removed from chemical warfare agents but are produced commercially for legitimate industrial applications.

Annual facility reports are required at production thresholds varying between 1 kg and 1 metric ton depending on the specific chemical involved. These reports must cover production, processing, consumption, and import/export data for the previous calendar year and anticipated data for the next year.

Affected facilities will be subject to an initial baseline inspection and no more than two routine inspections per year. Production thresholds for inspections vary between 10 kg and 10 metric tons depending on the specific chemical.

catch-all category covers ''other relevant facilities." Each of the four categories is discussed in Box 5.3.

Clearly the chief benefit expected from adherence to the Chemical Weapons Convention is reduced availability of chemical warfare agents for use by nationstates and for diversion to individual terrorist groups. The committee received no information on costs.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

Preliminary estimates are that 200 to 300 U.S. plants are likely to be affected by Schedule 2 requirements.

Schedule 3

Schedule 3 contains 17 chemicals produced commercially in high volume, including precursor chemicals that are several steps removed from chemical warfare agents such as phosphorous trichloride. This category also covers some highly toxic gases (e.g., phosgene) that were used as warfare agents in World War I that are currently produced at a level of millions of tons annually for industrial purposes.

Facilities producing 30 metric tons per year of any Schedule 3 chemical must be declared, and annual reporting is required. Those annual reports must cover production and import/export data for the previous calendar year and anticipated data for the next year. Those facilities producing 200 metric tons per year are subject to randomized inspection, with a maximum of two inspections per facility per year.1 Preliminary estimates are that roughly 1,000 U.S. plants are likely to be affected by Schedule 3 requirements.

Other Relevant Facilities

The category known as other relevant facilities includes facilities that produce any discrete organic chemical other than pure hydrocarbons or explosives. More stringent obligations are imposed on facilities that produce organic chemicals containing phosphorus, sulfur, or fluorine (so-called PSF chemicals), the basic building blocks of chemical warfare agents.

Annual reporting requirements for facilities in this category begin at 200 metric tons for non-PSF chemicals and 30 metric tons for PSF chemicals. Those reports must cover production data only for the previous calendar year.

Those facilities producing 200 metric tons per year are subject to randomized inspection, with a maximum of two inspections per facility per year. At least 10,000 U.S. plants are likely to fit this category.

1  

Note that there is a national limit on the combined number of inspections of Schedule 3 and "other relevant" sites.

SOURCE: Based on material in OTA (1993).

Applicability of the Chemical Drug Trafficking Act and Chemical Weapons Convention as Models

Of the two models discussed above, the CDTA and the CWC, the CDTA appears to be more relevant to the case of explosives precursors. The CDTA is concerned with limiting individuals' access to the chemicals used to manufacture illegal drugs, and controlling access by individuals is also the principal concern with chemicals that can be used to make explosives. There is even some overlap

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

of the chemicals in the two cases: several of the chemicals on the CDTA List II can also be used in making explosive materials, including sulfuric acid, potassium permanganate, and acetone. Although CDTA List I chemicals are generally specialty chemicals produced in small volumes, the List II chemicals are produced in much larger volumes, comparable to the volumes in which explosive precursors are manufactured.

Because the chemicals on CDTA's List II have many applications other than drug manufacture, the CDTA provides de minimis quantity thresholds below which no record keeping is required for transactions involving these chemicals. The comparatively low reporting thresholds for List I chemicals versus the higher thresholds for List II chemicals under the CDTA are an example of an attempt to match the stringency of control with the directness of the threat posed by the chemicals. Quantity thresholds are also likely to be useful in the regulation of explosive precursors, in order to reduce the costs of implementing controls. Thresholds could be set at such a level that record keeping would be required for quantities that could be made into large bombs (e.g., on the order of 100 pounds or more), while smaller-scale transactions would be unaffected.

In contrast to the CDTA, the CWC focuses on monitoring chemical production facilities for chemical warfare agents and potential precursors to prevent production and stockpiling of large volumes for use by nation-states. The CWC does not address the manufacture of chemical weapons by individuals or terrorist groups, such as that used in the attack by the Aum Shinri Kyo cult in the Tokyo subway.33

Nevertheless, the CWC does embody concepts that could contribute to the formulation of controls for explosives precursors. For example, the division of the chemicals controlled by the CWC into three schedules is based on the extent to which the chemicals are specific to chemical weapons, as opposed to being widely used in commerce. Facilities that produce the more widely used chemicals are subject to fewer requirements. By analogy, explosive precursor chemicals that have a wide range of commercial uses might be controlled less strictly than those with only a few applications beyond use as explosives.

Another important concept associated with the CWC has less to do with its specific provisions than the manner in which the treaty was developed. In the United States, a chemical weapons study group with stable representation from government and industry was able to discuss the issues for many years before the specifics of the treaty were developed.34 The early participation of industry was particularly important in educating government policymakers as to the workability

33  

 On March 20, 1995, members of the cult released the chemical agent sarin in the Tokyo subway system, killing 12 and injuring 5,500.

34  

 Will Carpenter, consultant, and Robert Mikulak, U.S. Arms Control and Disarmament Agency, testimony to the committee, March 3, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

of the treaty provisions. Similarly, in the case of explosives precursors, the establishment of workable controls requires an understanding of how these chemicals flow through the economy in all their applications. If possible, industry should be involved in the earliest stages of any discussions regarding controls on explosive precursor chemicals.

Other Approaches: Northern Ireland35

In response to the terrorist campaign of violence begun in the early 1970s, Northern Ireland specifically regulates access to explosive precursor chemicals. Initially, the favored bomb materials were stolen commercial explosives, but as security was increased, the bombers switched initially to chlorates and then to ammonium nitrate/fuel oil bombs. Ammonium nitrate fertilizer was readily available because of its broad agricultural use in Ireland.

In 1972, a regulation was passed in Northern Ireland requiring that AN fertilizer sold commercially contain no more than 79 percent AN, with the remaining 21 percent typically consisting of dolomitic limestone, or chalk. The effect of this regulation was to thwart the terrorists for a time, but it was not long before bombers realized that the AN could be separated from the chalk by mixing the fertilizer with water and filtering the chalk out. Pure AN could then be recovered by drying the filtrate.

In 1972, controls were placed on pure AN, sodium chlorate, and nitrobenzene; in 1973, on sodium chlorite; in 1974, on sodium and potassium nitrate; and, in 1976, on sodium nitrite. Also during this period, tighter controls were placed on access to high explosives and low explosives such as black and smokeless powders and pyrotechnic mixtures.

The general strategy used in Northern Ireland for choosing explosive precursor chemicals to control was to identify vigorous oxidizing agents36 and then consider the quantities in which they were available to terrorists. Some strong oxidizing agents, such as potassium permanganate, would be hard to purchase in quantities large enough to make a bomb of any significant size, and attempted large purchases would likely alert authorities. Therefore, potassium permanganate, potassium perchlorate, and other oxidizers not available in large quantities were not controlled. In contrast, sodium chlorate was available in large quantities as a weed killer and therefore was controlled. Legislators made the final decisions about which chemicals to control, in consultation with the agricultural industry.

Urea was not considered for control because it is not an oxidizer. Nitric acid

35  

 This section is based on a personal communication from Gerard Murray, Forensic Science Agency of Northern Ireland, Belfast, Northern Ireland, May 22, 1997.

36  

 Nitrobenzene is the only chemical on the list that is not an oxidizing agent. It was chosen for control because it was being used as a fuel with ammonium nitrate.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

itself has not been subject to controls. It was felt that terrorists would not want to handle large quantities of such a corrosive chemical, especially when AN was already available. In any case, if nitric acid became a problem, controls could be imposed relatively quickly.

To obtain any quantity of the seven controlled precursors in Northern Ireland, a prospective buyer goes to the police station and must justify why the chemical is needed and how much is to be used. The police then check the buyer to validate his request and an approved buyer is issued a license to purchase a particular quantity. Most purchasers are industrial users such as fertilizer manufacturers who purchase regularly and in large quantities. Universities are commonly issued licenses for smaller amounts, e.g., 500 grams. There are no quantity thresholds below which a license is not required for purchase of controlled chemicals. Sodium chlorate is permitted to be sold commercially to unlicensed purchasers, but only if it contains 16 percent calcium chloride (a safety measure designed to ensure flame suppression).

The 25-year experience in Northern Ireland indicates that controlling chemical precursors for explosives has been successful in reducing the use of controlled chemicals, including pure ammonium nitrate, in bomb making. However, ammonium nitrate that has been diluted to 79 percent is commercially available and has been, and still is, effectively utilized in large bombs in a campaign of urban terrorism.

An Example of Voluntary Industry Control of a Precursor Chemical: "Be Aware for America"37

In response to the Oklahoma City bombing and the resulting concern about terrorist access to ammonium nitrate and other fertilizers, the affected industries created the "Be Aware for America" initiative. The program and publicity materials were developed collaboratively by the Fertilizer Institute; the Bureau of Alcohol, Tobacco, and Firearms; the Association of American Plant Food Officials; and the Agricultural Retailers Association. The program's purpose is to alert all fertilizer distributors to customers who do not appear to be buying fertilizer for a legitimate use, and it covers ammonium nitrate as well as sodium nitrate and potassium nitrate fertilizers sold in bulk. The program uses brochures and a video training tape that describe behaviors that should be regarded as suspicious, as well as posters designed for display in sales areas. It is discussed in periodic newsletters to distributors and is mentioned prominently at distributor trade shows. There is no monitoring for performance, and no record keeping is required,

37  

 This section is based on testimony presented to the committee by Gary Myers and Ford West, the Fertilizer Institute, March 3, 1997, and on a personal communication from Gary Myers and Ford West on June 10, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

thus making verification of the extent of industry commitment to the program impossible.

Based on the committee's limited review, at least some distributors appeared to take the program seriously, and some required the purchaser to produce identification. A recent study reported positively on the "Be Aware for America" program and a parallel effort in Canada but concluded that the programs are "somewhat limited in scope and have no provisions for implementation on a continuing basis" (IFDC, 1997, p. 10-6).

The committee queried a number of local law enforcement agencies to determine the extent of their involvement with the "Be Aware for America" program. One, the bomb squad of the Los Angeles County Sheriff's Department, which serves an area of approximately 4,000 square miles and 10 million citizens in both urban and rural areas, had not heard of the program.38 A limited survey of law enforcement involvement in the "Be Aware for America" program was conducted at the committee's request by the National Law Enforcement and Corrections Technology Center, Rocky Mountain Region (NLECTC-RM). Results from the survey, which included 10 respondents from eight states (see Appendix L), showed that the law enforcement organizations contacted lacked knowledge of and information about the program.39 Currently, fertilizer vendors must develop their own procedures for notifying law enforcement officials, as well as for collecting and storing records of transactions.

The committee concluded that while the "Be Aware for America" program should be supported as a first step toward increasing industry and public awareness, it must be strengthened through more rigorous implementation and the greater involvement of law enforcement organizations.

The NLECTC-RM offered several suggestions for accomplishing these goals, including one that a partnership be established between the fertilizer industry and national law enforcement organizations (e.g., the National Sheriffs Association and the International Association of Chiefs of Police) to increase members' awareness of the program. The center also considered that the program naturally parallels such public/law enforcement partnerships as "Crime Stoppers," "Neighborhood Watch," and others.

It suggested further that advertising the "Be Aware for America" program to the general public would have several benefits: deterring would-be bombers by convincing them that their activities are being scrutinized closely; giving vendors an incentive to continue the program; and motivating the public by letting them know that they are the "eyes and ears" for each other and for law enforcement.

38  

 Lt. Thomas Spencer, Los Angeles County Sheriff's Department, personal communication, June 1997.

39  

 For example, of 10 law enforcement agencies responding to the survey, only 1 knew of the program.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

Finally, the NLECTC-RM urged that input be solicited from respected law enforcement professionals and prosecutors to optimize implementation. The committee endorses these suggestions, having concluded that the "Be Aware for America" initiative is a good start that nevertheless has not involved local and national law enforcement organizations as well as it should for the program to be broadly effective and sustainable. The committee urges that these shortcomings be addressed.

RECOMMENDED CONTROLS ON SHORT-LIST PRECURSOR CHEMICALS AT VARIOUS THREAT LEVELS

Options to Be Considered

For very large bombs (hundreds to thousands of pounds), improvised explosives have been the materials of choice in the United States. A wide range of options is available for controlling criminal access to precursor chemicals that can be used to make these large bombs. Both political and technical considerations are important; the committee emphasizes the technical aspects. The following options, in order of increasing stringency, should be considered:

  1. Establishing and expanding industry-sponsored voluntary programs such as "Be Aware for America." Such programs can make sellers of precursor materials more alert to attempted purchases by terrorists or suspicious parties. The existence of such programs may deter less dedicated bombers and increase public confidence that something is being done to prevent future bombings.

  2. Requiring the prospective purchaser to produce proof of identity and the seller to keep records of the transaction. This option, which could be modeled on the provisions of the Chemical Diversion and Trafficking Act described above, could provide a paper trail to the last legal purchaser. Forms of identification to be required might include a photograph and/or fingerprint from the purchaser that would be attached to the seller's receipt. This requirement could provide a significant benefit to law enforcement, as well as a psychological deterrent to would-be bombers.

  3. Requiring sellers to have a license and purchasers to have a permit . This option, which might be modeled on the current federal controls on explosives in interstate commerce, could be designed with varying degrees of stringency (waiting periods, background checks, and so forth) depending on the degree of perceived threat.

  4. Requiring chemicals to be sold in a nondetonable from (as determined by a well-defined test). Note, however, that there are technical difficulties with establishing a material as "nondetonable" (see Chapter 4).40

40  

 Large bombs have been made with 79 percent AN fertilizer, which was initially thought to be nondetonable.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
  1. Restricting or banning sales to certain markets. This approach would remove one source of supply, but the inconvenience and loss of access for legal purchasers would have to be balanced against the effectiveness of the ban in denying access to would-be bombers.

All of these options would lead to an increased likelihood of reporting suspicious behavior or would produce record trails that might be useful in identifying the last known legal purchaser. The chief effect on potential terrorists would be to prevent them from buying a preferred material, consequently forcing them to steal it, switch to another material, or abandon their illegal activities. The committee heard testimony at its meetings and received reports from the Swiss police and British Ministry of Defence authorities that increasing the barriers to access is an effective strategy to reduce the threat of bombings (see Appendix F).

The committee recognizes that materials on its short list may—in some streams of their commerce—already be quite traceable and adequately controlled. For example, good records are maintained for sales of the very corrosive and poisonous chemical concentrated nitric acid, including quantities and purchasers. It is likely that good sales and distribution records are also kept for ammonium nitrate sold to the explosives manufacturing industry or even directly to operators for mixing with fuel oil at mine sites. However, mine operators may not maintain accurate records of use, and so theft of even substantial quantities might be hard to detect. Unless theft from mine sites were to become the favored means of obtaining ammonium nitrate, imposing requirements for detailed record keeping on mine operators would be an unwarranted escalation of control at this time.

The following discussion describes for each chemical on its short list (see Table 5.2) the committee's recommendations for controls at three threat levels: the current threat, an increased threat, and a greatly increased threat. In many cases, current sales and control practices are adequate, but for some materials and market segments the committee recommends significant increases in controls for the current threat level.

In considering options for controlling access to its short-list precursor chemicals that are currently of greatest concern, the committee tried to strike an appropriate balance between making these chemicals easier to trace to the last legal purchaser and more difficult to obtain by individuals and groups with terrorist intentions, while still preserving maximum freedom and minimum costs for legitimate users.

Ammonium Nitrate

Availability, Production, and Use

In 1996, U.S. production of ammonium nitrate was approximately 9.9 million short tons (IFDC, 1997). Also in 1996, U.S. demand for solid AN was 4.9

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

million short tons,41 with 2.7 million short tons used for agriculture and 2.2 million short tons used for explosives.42 Solid AN is produced in two forms: a high-density fertilizer-grade prill suitable for agricultural use, and a low-density industrial-grade prill used primarily for blasting. The discussion below focuses primarily on the fertilizer-grade material.

Approximately 90 percent of all fertilizer-grade AN is shipped as prills and used as bulk material. Of the 10 percent that is sold in packaged form, only half is bagged at the production site; the other half is bagged at subsequent points in the distribution system (IFDC, 1997), either as a mixture with other fertilizer ingredients or as pure ammonium nitrate. Small amounts of ammonium nitrate also have myriad other uses, for example, in "instant" cold-producing compresses for medical use, but these small quantities are not thought to present a significant threat as sources for the manufacture of large bombs.

Consistent with their widespread use, both industrial-and fertilizer-grade AN prills are shipped by truck, rail car, and barge around the country in massive quantities. The vehicles generally do not have locks and may sit untended in isolated places for days or weeks at a time. Further, the sheer quantities of AN involved in these shipments are such that the loss of a few tons along the way would not be considered remarkable. The poor security of this distribution system offers an attractive means by which would-be bombers can obtain access to large quantities of AN undetected. The committee is not aware of any evidence that theft of AN from trucks, rail cars, or barges is currently a significant source of material for would-be bombers. However, as other avenues of access become restricted, measures for improving the security of the distribution system should be considered.

Options for Control
Current Threat

Ammonium nitrate sold in bulk as a fertilizer is currently subject to the industry's "Be Aware for America" initiative. The committee supports this initiative but does not believe that the means are in place to ensure that the program is being carried out effectively by all distributors. Consequently, the committee recommends that the "Be Aware for America" program for sales of bulk nitrate fertilizers be strengthened by more rigorous implementation and by establishing partnerships with local and national law enforcement agencies.

The current practice of selling packaged pure ammonium nitrate and other

41  

 Only about one-third of the AN used as a fertilizer is in solid form; two-thirds is used as an aqueous solution with urea.

42  

 Paul Rydlund, El Dorado Chemical, testimony to the committee, March 3, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

nitrate fertilizers in drums and bags (larger than 25 pounds) is a cause for concern and an area in which the committee believes some significant changes are currently justified. For sales to larger commercial purchasers, a strengthened "Be Aware for America" approach coupled with the retention of routine business records is adequate. However, the sale of packaged pure ammonium nitrate to small retail consumers, especially at outlet stores, is potentially an easy source of explosive materials for terrorists. It is hard to see how a "Be Aware for America" program would be feasible under these conditions.

Consequently, the committee recommends that packaged ammonium nitrate-based fertilizers typically sold in retail outlets should be sold only as nondetonable mixtures (as defined by a standard test protocol of the kind described in Appendix H). Alternatively, the purchaser should be required to produce identification and the seller to keep records of the transactions.

Such an "either-or" policy would allow retailers who choose to continue selling ammonium nitrate to follow whichever course involves the least cost to them. The record-keeping alternative would be the default requirement until an acceptable test protocol could be developed and implemented. Such a policy would impose a minor hardship on homeowners who use these fertilizers for their lawns or personal gardens, but this does not seem a prohibitive price to pay for the likely deterrence provided. In fertilizers for which the high nitrogen content is critical, urea may be used as the diluent, even though some new packaging may be required.43 In addition, most home-use fertilizer sold today may already be a nondetonable mixture of ammonium nitrate with other nutrients. The ammonium nitrate content of compound fertilizer rarely exceeds 40 percent. Although only a few grades of compound fertilizer have been tested for detonability, those that have been tested were significantly less sensitive and energetic than pure AN (IFDC, 1997). Thus this major part of the home-use market would be unaffected.

Increased Threat

At an increased threat level, tighter controls on sales of bulk ammonium nitrate fertilizer offer the greatest near-term opportunity for restricting access to this bomb ingredient. In that case, record-keeping practices similar to those required under the illicit drug precursor controls should be considered (see discussion above of the CDTA). Normal business records could perhaps be used as long as they were retained for a prescribed period and were available to the appropriate enforcement authorities. In addition, sellers should be required to report suspicious behavior during a sale within a short period after the sale. Purchasers should be required to show positive identification but should not be

43  

 Solid mixtures of urea and ammonium nitrate tend to absorb water to form a sticky mass.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

subjected to background checks. The cost for such an escalation of control should be minimal.

Greatly Increased Threat

For a greatly increased threat of illegal bombing attacks involving bulk ammonium nitrate fertilizers, consideration should be given to requiring licenses for sellers and permits for buyers. Many possible requirements might be imposed for obtaining a license or permit, and the committee does not consider itself qualified to suggest the best combination for any of the many segments of the fertilizer market.

For a greatly increased level of threat involving potential use of packaged ammonium nitrate, an alternative to a ban on detonable chemicals might be a program requiring licenses for sellers and permits for users, similar to the approach recommended for controlling bulk sales of these materials.

Theft of Ammonium Nitrate

Any controls on the sale or use of commercial chemicals clearly require that the materials of concern not be easily obtainable via theft. Consequently, any regulation of ammonium nitrate (or other chemicals discussed in this chapter) implies that increased requirements for the security of inventories be placed on manufacturers, shippers, and vendors.

Other Key Short-List Precursor Chemicals

In addition to ammonium nitrate, a number of other chemicals can be used to improvise bombs. Those posing the greatest threat in the United States are presented in the committee's short list in Table 5.2. The committee points out that this list could change with time and should be reviewed periodically.

Sodium Nitrate and Potassium Nitrate

Sodium nitrate has no major producers in the United States, but approximately 110,000 short tons of the material are imported annually from Chile, primarily for use with high-value vegetable crops, but also for other purposes (IFDC, 1997). Like potassium nitrate (see below), it is available from chemical supply houses in large quantities.

Potassium nitrate is produced in much smaller volumes than is ammonium nitrate (U.S. capacity is less than 220,000 short tons per year) but is an important fertilizer used on high-value fruit and vegetable crops (IFDC, 1997). The material's availability in large quantities, both as a fertilizer and from chemical supply houses, makes it a potential threat for use in large bombs.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
Nitric Acid and Urea

Urea can be reacted with nitric acid to produce the explosive urea nitrate, the material used in the World Trade Center bombing. Urea is a nondetonable, ubiquitous, and inexpensive material with an annual production volume in North America of 19 million short tons (IFDC, 1997). It is used extensively as a fertilizer, as a noncorrosive ice-melting material at public facilities and in private homes, and as a reagent in many chemical processes. Because urea is a relatively innocuous chemical with a wide range of uses, the committee believes that preventing access to urea nitrate for illegal purposes is more easily achieved by controlling the other critical component required to make an explosive: nitric acid.

Nitric acid, which is toxic and highly corrosive, has many industrial applications but is not commonly available to the general public. For that reason, the committee believes that sales of nitric acid are much more traceable than those of urea. Furthermore, controls on nitric acid would provide greater leverage in efforts to prevent bomb attacks than would controls on urea, because nitric acid can be reacted with a wide range of organic materials (e.g., cellulose, glycerine, and amines) to produce explosives. Although much of the nitric acid produced is used in on-site chemical processes, a large amount is shipped in tank cars to chemical processing plants or packaged in drums for sale to commercial businesses such as etchers and metal platers. All of these uses are amenable to good sales record keeping. The committee believes that such sales records are probably adequate for current law enforcement needs.

Nitromethane

Nitromethane, an energetic material used commercially as a solvent, chemical intermediate, and fuel in racing engines and hobbyist activities, has been promoted by some Internet sites and publishing houses that cater to amateur bomb makers as a powerful adjunct fuel in ammonium nitrate bombs.44 It is itself detonable and could be used in bombs without the addition of ammonium nitrate. The committee's greatest concern is the potential for access to large quantities. Early advice from Internet sites and other sources recommended that nitromethane be obtained from automotive race tracks,45 but apparently distributors of nitromethane are now careful about whom they sell to, and this option is less viable.

44  

 See footnote 25 for examples of written material.

45  

 ''Months before the Oklahoma City bombing … McVeigh, using [an alias] approached (a racing fuel salesman) at a dragstrip near Topeka, Kan., to ask about buying nitromethane racing fuel and anhydrous hydrazine-a rocket fuel. Together, the two can be made into a bomb." Howard Pankratz and Peter G. Chronis, Denver Post, May 2, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
Hydrogen Peroxide and Acetone

Hydrogen peroxide can be reacted with acetone to make the powerful explosive TATP, which has been used by terrorists abroad but not thus far to any great extent in the United States.46 It can be made in large quantities but is extremely unstable and dangerous to handle.

Acetone, one of the most common organic solvents, can be purchased readily from many sources in large quantities. As in the case of nitric acid and urea, controlling access to TATP is achieved more readily by limiting the availability of hydrogen peroxide than by controlling acetone. As with controls on nitric acid, controls on hydrogen peroxide would be preferred because hydrogen peroxide can be reacted with chemicals other than acetone to produce explosives.

Hydrogen peroxide is a strong oxidizer sold in 3 to 70 percent solutions in water. It has many applications as a disinfectant, as a reagent in chemical syntheses, and as a bleaching agent for wood pulp, clothing fibers, and human hair.

Sodium Chlorate and Potassium Chlorate

Chlorates have a long history of use in explosive formulations. In 1885, 240,000 pounds of a mixture of potassium chlorate and nitrobenzene, along with 42,000 pounds of dynamite, were used to blast a portion of Hell Gate Channel in New York Harbor (Colver, 1918). Flash powder, a mixture of potassium chlorate, sulfur, and powdered aluminum, appears frequently in statistics on bombing incidents in the United States (ATF, 1997).47 A mixture of potassium chlorate and red phosphorus is used in the common safety match ("Armstrong's powder") (Oxley, 1997).

A survey of the "do-it-yourself" bomb-making literature indicates that mixtures of chlorate salts with sugar are by far the most commonly recommended formulations (Oxley, 1993). Depending on the locale, either the sodium or potassium salt may be more available. Before the imposition of controls on chlorates in the early 1970s, Northern Ireland was plagued with sodium chlorate/sugar bombs, because sodium chlorate was widely available for use as a weed killer.

Potassium Perchlorate

Potassium perchlorate, a powerful oxidizer used in pyrotechnic formulations, can be obtained in quantity from chemical or pyrotechnic supply houses. It

46  

 Richard Strobel, ATF, personal communication, June 6, 1997.

47  

 Photoflash/fireworks powders accounted for 17 percent of fillers used in destructive devices in 1995 (ATF, 1997).

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

is one of the more common oxidizers found in U.S. bomb incidents involving oxidizer-fuel mixtures.48

Key Chemicals: Options for Control

All of the key precursor chemicals described above have some degree of recognized hazard associated with their use. As a result, their handling is carefully controlled by industrial users and university laboratories. However, as discussed above, each chemical has outlets through which a determined bomber might obtain significant quantities. Small, mail-order chemical supply houses are a significant uncontrolled source of chemicals that could be used in improvised explosives.49

Current Threat

Currently, bombing incidents involving any of the improvised oxidizer-fuel mixtures on the short list constitute less than 2 percent of all such incidents in the United States (FBI, 1997). Furthermore, with the exception of the urea nitrate bomb used at the World Trade Center in New York, bombing incidents involving these chemicals have not resulted in major loss of life or property damage in the United States. In fact, the World Trade Center bombing was an unusual case, in that one of the convicted bombers was a chemical engineer, employed by a major U.S. materials company, who presumably managed to obtain the chemicals through his established professional contacts with chemical suppliers (FBI, 1997). Therefore, at the present threat level, the committee recommends no new controls on sales of nitric acid, nitromethane, hydrogen peroxide, sodium nitrate and potassium nitrate, sodium chlorate and potassium chlorate, and potassium perchlorate, and thus by extension, acetone and urea.

Increased Threat

At an increased threat level, large-volume sales of the following chemicals should be documented by record keeping that requires the purchaser to produce identification and the seller to maintain records of the transaction for a specified period of time in a form accessible to law enforcement: bulk nitrate fertilizers, concentrated nitric acid, concentrated hydrogen peroxide, nitromethane, sodium nitrate, potassium nitrate, sodium chlorate, potassium chlorate, and potassium

48  

 Richard Strobel, ATF, personal communication, September 9, 1997.

49  

 Richard Strobel, ATF, testimony to the committee, March 24, 1997.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

perchlorate. The additional cost of this requirement has not been assessed, but the committee anticipates that it would be small since much of the required record keeping is already being done. The principal cost increase is expected to occur at the distributor level.

Greatly Increased Threat

If use of short-list chemicals in improvised explosives were to become common, then requiring licenses for sellers and permits for users would probably become feasible at all sales levels. Costs to implement requirements for licenses and permits could range from slight to considerable, and in some cases could result in market disruption. For instance, if the cost of nitric acid for small plating and etching facilities were increased significantly as a result of more stringent requirements for its purchase, alternative products and materials might become competitive and cause business failures in then-current markets. Under conditions of extreme threat, sales of the chemicals could be banned in all but carefully controlled markets.

Summary of Recommended Controls

The committee's recommendations for controls on access to precursor chemicals are summarized in Table 5.3. The full recommendations are given in the final section of this chapter.

Costs and Benefits of Recommended Controls50

The costs of implementing the committee's recommended controls on chemical precursors would increase with increasing threat level and would be incurred by law enforcement, industry, and consumers. Increased costs to consumers are not discussed here. The committee notes that the time and resources available to it did not permit a rigorous analysis of the costs associated with each of the options for controls, which would have to take into account how the chemicals flow through the economy, including annual production, import and export statistics, the number of legitimate uses of the chemical, the number of retail outlets, and so on. The committee urges that such a rigorous analysis be done before implementation of any controls, and that the affected industries participate fully in the analysis.

50  

 The potential cost impacts of uniform national regulations for the purchase of explosives are discussed above in the section titled "Adopting Uniform National Regulations for the Purchase of High Explosives in the United States."

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

TABLE 5.3 Recommened Controls For Short-List Precursors at Various Threat Levels

 

Precursor

Threat Level

Bulk Ammonium Nitrate and Other Nitrate Fertilizers

Packaged Ammonium Nitrate and Other Nitrate Fertilizers

Sodium Nitrate Potassium Nitrate Nitric Acid (concentrated) Nitromethane Hydrogen Peroxide (concentrated) Sodium Chlorate Potassium Chlorate Potassium Perchlorate

Current

Strengthen voluntary efforts

Make retail fertilizers nondetonable or require purchaser identification and seller record keeping

Continue currently acceptable procedures

Increased

Require purchaser identification and seller record keeping

Use controls indicated for current threat level

Require purchaser identification and seller record keeping

Greatly increased

Require licenses for sellers and permits for purchasers

Make retail fertilizers nondetonable or require licenses for sellers and permits for purchasers

Require licenses for sellers and permits for purchasers or, if necessary, ban sales in certain markets

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
Law Enforcement

If the "Be Aware for America" program were strengthened as recommended, law enforcement at both local and national levels would incur increased costs for the required additional personnel and training. At increased threat levels, requirements that sellers have licenses and purchasers have permits for selected chemicals could lead to substantially greater use of law enforcement personnel and resources at all levels.

The benefits to law enforcement of the recommended controls would be substantial. The availability of sales and distribution record trails for critical bomb-making materials would provide investigators with after-the-fact information as well as early warnings of illicit activity. Furthermore, if criminals were aware that sellers were actively engaged in record keeping and efforts supporting detection, they might be less likely to use these materials for illegal activities. In that case, law enforcement officers would be relieved of the burden of investigating significant numbers of incidents involving the use of precursor chemicals, especially "nuisance" bombs created by individuals experimenting for amusement.

Industry

Additional costs to industry resulting from implementation of the recommended controls would vary from negligible to substantial, depending on the type of control.

  • Requiring purchaser identification and seller record keeping. For most large transactions involving bulk chemicals, normal records would be sufficient, although some additional costs might be incurred for filing and storing records of transactions. For small retail distributors, the recommended record-keeping requirements might be new but likely would entail addition of information to already existing required records of financial transactions. Costs could be reduced if records were not required for purchases below certain threshold amounts.

  • Requiring licenses for sellers and permits for users. Costs would vary significantly depending on the requirements for obtaining a license or permit.

  • Requiring that chemicals sold in certain markets be nondetonable . Assuming the availability of a reliable test of detonability and acceptable inerting technologies, industries in the affected markets would incur an initial cost for testing the product and reformulating it if necessary. Most existing formulations of packaged AN fertilizers sold at retail outlets are mixtures of AN with other fertilizer ingredients that would test as nondetonable, and so market disruptions would likely be minimal.

    A widely accepted test of detonability is essential to protect industry from

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

liability suits of the kind filed against the ammonium nitrate industry in the wake of the Oklahoma City disaster (Hassan, 1996).

  • Banning sales in certain markets. This approach is clearly the most expensive and potentially disruptive option for controlling access to high-risk chemical precursors. Some shifting to the use of urea in place of ammonium nitrate as a fertilizer might occur if detonable packaged forms of AN were banned from retail markets, although a shift toward increasing use of urea, driven by urea's lower manufacturing costs and higher nitrogen content, has already been reported.51

LEGAL ISSUES

Because the committee's recommendations in this chapter are mostly regulatory rather than technical, their legal ramifications are perhaps more readily apparent. For example, laws enacted at either the federal or state level (or both) to track the sale and purchase of explosive materials and certain precursor chemicals may affect the civil liability of those in the explosives and relevant chemical industries. They also may precipitate lawsuits challenging the constitutionality of such measures. Obviously, the outcome of these liability and regulatory issues will significantly affect the costs and benefits associated with the recommended controls. Thus, a brief analysis of these issues is provided below. A more extensive discussion appears in Appendix G.

Civil Liability

Even without a regulatory statute, the makers and suppliers of explosives and precursor chemicals are subject to a number of legal duties that determine how such commodities are to be constructed, handled, and distributed. Anyone who participates in moving explosives or hazardous precursor chemicals through the chain of distribution may be held liable under product liability, ultrahazardous, or abnormally dangerous activity theories if their goods expose others to unreasonable or unusual risks of harm (see Appendix G, pp. 279-28052). Likewise, retailers

51  

 Increased use of urea is described in "Ammonium Nitrate," Chemical Product Synopsis, Mannsville Chemical Products Corporation, Adams, N.Y., April 1996. Although nitrogen fertilizers are broadly substitutable if applied properly, the best choice in a particular case depends on factors such as type of crop, soil conditions, climate, farming techniques, and cost. To be usable by most plants, nitrogen must be in the form of nitrate. Thus, ammonium nitrate is more quickly taken up than is urea, whose nitrogen must be converted to nitrate by soil microorganisms—a process that can take several weeks (IFDC, 1997, p. 5-4).

52  

 Note that page numbers in parentheses in this "Legal Issues" section cross-reference related, more detailed discussion in Appendix G, "An Analysis of the Legal Issues Attendant to the Marking, Inerting, or Regulation of Explosive Materials."

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

may be required to pay damages if they sell such dangerous instrumentalities to persons who they know, or have reason to believe, will deploy the devices in a harmful manner (pp. 279-280). Sellers who voluntarily undertake to screen buyers of explosive materials (like the merchants currently participating in the Fertilizer Institute's "Be Aware for America" program) may be found negligent for failing to do so properly, although for policy reasons courts have been reluctant to impose liability in such cases (pp. 280-281).

Should the committee's regulatory proposals be enacted into law, those in the business of marketing explosive products and their constituent chemicals would face additional civil responsibilities. Failure to comply with regulatory controls would likely be considered conclusive, presumptive, or persuasive evidence of unreasonable conduct and could be used to sustain a claim of negligence per se (pp. 281-282). Conversely, while a party's compliance with a statute or regulation may improve his or her chances of avoiding liability, it usually will not be dispositive (pp. 281-282).

Constitutionality of Proposed Regulatory Controls

As in the case of the sales restriction on packaged ammonium nitrate discussed in Chapter 4, the committee's recommendations here (i.e., to extend the present federal licensing scheme to reach purely intrastate purchases and to institute positive purchaser identification and other controls on retail sales of concentrated nitric acid, high-strength hydrogen peroxide, and pure nitromethane) may come under constitutional attack. If adopted by the federal government, such regulations will be sustained only if they fall within the delegated authority of Congress, and even then, only if they treat all regulated parties fairly.

As discussed in Chapter 4, Congress has the authority to regulate any matter that "substantially affects" interstate commerce (Appendix G, pp. 283-288). Recent U.S. Supreme Court case law suggests both that the activity affected must be commercial in nature and that it must not be an area of traditionally local concern. The profit-making business of explosive materials manufacture, distribution, and sale clearly seems to be "commercial." Because most states already regulate this industry, however, it is more debatable whether the distribution of explosives is a matter of "traditionally local concern." Nevertheless, given concurrent federal regulation of the industry and the difficulty of solving the terrorism problem at the local level—since terrorists may simply cross state lines to a state where regulation is more lax—there is a good argument that the matters regulated are not of local concern. Furthermore, the serious impact on medical costs, national fears of interstate travel, and lost man-hours from even a single serious incident of terrorism suggest that the free availability of legally obtained explosive materials and their precursors does "substantially affect" interstate commerce. Thus, so long as Congress does not attempt to compel state or local governments to administer its regulatory programs (a tactic that would run afoul of the Tenth

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

Amendment), each of the committee's recommended controls, including the uniform national regulations on the purchase of explosives, should survive constitutional scrutiny (pp. 288-291).

These proposals also seem sustainable on fairness grounds. Because none of the suggested regulations infringe fundamental rights, courts will uphold these measures if they are supported by any legitimate governmental objective and if the means chosen are rationally related to that end. There seems little doubt that curbing criminal access to explosive materials is a legitimate goal of government, and that placing identification, record-keeping, licensing, or permit restrictions on the sale and acquisition of such dangerous commodities is a rational way of combating the problem of bomb-blast terrorism. Thus, should the proposed regulations be challenged on grounds of equal protection (pp. 292-294), substantive due process (pp. 294-295), or uncompensated taking (pp. 295-297), such fairness arguments are likely to fail.

Finally, the committee also recommends that uniform national regulations for the purchase of explosives be developed and implemented. One way of achieving uniformity is for the federal government to enact legislation that would preempt all additional or different state laws. Thus, industry would have to worry about only one scheme: the federal one. So long as Congress is clear about its intention, preemption of state laws would likely be constitutionally permissible under the supremacy clause.

CONCLUSIONS AND RECOMMENDATIONS

Conclusions

Compared with some countries, the United States has relatively lax federal controls on the purchase of explosives. Although some states do have strict purchasing requirements, many states allow individuals to purchase explosives without background checks or adequate verification of their identity.

Many high explosives used in bombings are stolen. Common targets of theft are believed to be small end users, many of whom may not have the legally required magazines for storing high explosives securely. Explosives stolen from these end users are available to bombers for use as detonators, boosters, or as the main charge in improvised bombs.

Effective bombs can be synthesized from a variety of readily available chemical precursors. Those chemical precursors that pose the greatest threat in the United States were identified by the committee according to the following criteria:

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
  • The chemical is available in substantial quantities (e.g., on the order of 100 pounds or more);

  • The chemical is an essential component of an explosive system in significant use or with the potential for significant use, where significant use is defined in terms of deaths, injuries, and property damage; and

  • The chemical is a critical precursor, i.e., one not easily replaced in generating an explosive system.

It is not feasible to control all possible chemical precursors to explosives. Efforts to control access should focus on the chemicals identified by the committee as current candidates for control in the United States. These chemicals are ammonium nitrate, sodium nitrate, potassium nitrate, nitromethane, concentrated nitric acid, concentrated hydrogen peroxide, sodium chlorate, potassium chlorate, and potassium perchlorate. Urea and acetone also meet the criteria for control but are adequately controlled if access to nitric acid and hydrogen peroxide is limited. This list of chemicals may change over time if the materials preferred for bomb making change.

Incremental increases in controls on a few carefully selected precursor chemicals can help keep these chemicals out of the hands of bombers. Sales of bulk chemicals may be controlled at a level different from that applied to retail sales.

Many models exist for controlling access to explosive precursor chemicals. Perhaps the most relevant are the regulatory controls placed on chemicals used in the synthesis of illegal drugs. Also, the voluntary "Be Aware for America" program53 established by the fertilizer industry to keep ammonium nitrate and other explosive fertilizer chemicals out of the hands of bombers appears to be a positive step, but it must be improved by more rigorous implementation and stronger interaction with law enforcement.

Recommendations

  1. Criminal access to explosives in the United States should be made more difficult by the following legislative actions:

  • Creating uniform national regulations for the purchase of commercial high explosives. At a minimum, these regulations would extend current interstate

53  

 The program and publicity materials were developed collaboratively in 1995 and are described in a brochure, "Be Aware for America: 1995," developed by the Fertilizer Institute; the Bureau of Alcohol, Tobacco, and Firearms; the Association of American Plant Food Officials; and the Agricultural Retailers Association.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

controls (i.e., federal requirements for licensing and verification of compliance with storage requirements) to cover intrastate explosives transactions; and

  • Giving the Bureau of Alcohol, Tobacco, and Firearms the authority and resources to ensure that all purchasers of high explosives use secure magazines if the explosives are to be stored.

  1. The options below should be considered for controlling criminal access to the precursor chemicals listed by the committee: ammonium nitrate, sodium nitrate, potassium nitrate, nitromethane, concentrated nitric acid, concentrated hydrogen peroxide, sodium chlorate, potassium chlorate, and potassium perchlorate. The most appropriate option for control depends on the perceived level of threat. Options for consideration include the following:

  • Establishing voluntary industry controls on sales similar to the ''Be Aware for America" program;

  • Requiring that purchasers show identification and sellers keep records of transactions;

  • Requiring that sellers have licenses and that purchasers obtain permits;

  • Making the listed chemicals nondetonable by addition of certain additives; and

  • Banning sales of listed chemicals in certain markets.

  1. At the current level of threat, the committee recommends the following:

  • The "Be Aware for America" program for sales of bulk nitrate fertilizers should be strengthened by more rigorous implementation and by establishing partnerships with local and national law enforcement agencies.

  • Packaged ammonium nitrate-based fertilizers typically sold in retail outlets should be sold only as nondetonable mixtures (as defined by a standard test protocol developed in response to Recommendation 9). Alternatively, the purchaser should be required to produce identification and the seller to keep records of the transaction.

  • Additional controls should not be placed on sales of any other precursor chemical at the present threat level.

  1. At an increased threat level, the committee recommends the following additional controls:

  • Purchasers of bulk nitrate-based fertilizers and large quantities of sodium nitrate, potassium nitrate, nitromethane, concentrated nitric acid, concentrated hydrogen peroxide, sodium chlorate, potassium chlorate, and potassium perchlorate

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×

should be required to produce positive identification. Sellers should be required to keep records of sales transactions for a specified period of time.

  1. At greatly increased levels of threat, the committee recommends the following additional controls:

  • Sellers of bulk detonable nitrate fertilizers should be required to have licenses, and purchasers should be required to obtain permits.

  • Packaged ammonium nitrate-based fertilizers typically sold in retail outlets should be sold only as nondetonable mixtures (as defined by a standard test protocol developed in response to Recommendation 9). Alternatively, sellers should be required to have licenses and purchasers should be required to obtain permits.

  • Sellers of sodium nitrate, potassium nitrate, nitromethane, packaged concentrated nitric acid, concentrated hydrogen peroxide, sodium chlorate, potassium chlorate, and potassium perchlorate should be required to have licenses and purchasers should be required to obtain permits. Alternatively, sales of these chemicals in some markets should be banned.

  1. The list of chemical precursors to be controlled should be reevaluated periodically to correlate with ongoing assessment of the level of threat posed by illegal use of explosives. Bombers have demonstrated that they can change their tactics in response to the implementation of controls or shifts in the availability of particular chemicals or precursors.

Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
×
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Suggested Citation:"5 Limiting Criminal Access to Explosives and Precursor Chemicals." National Research Council. 1998. Containing the Threat from Illegal Bombings: An Integrated National Strategy for Marking, Tagging, Rendering Inert, and Licensing Explosives and Their Precursors. Washington, DC: The National Academies Press. doi: 10.17226/5966.
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In response to the rising concern of the American public over illegal bombings, the Bureau of Alcohol, Tobacco, and Firearms asked the National Research Council to examine possible mechanisms for reducing this threat. The committee examined four approaches to reducing the bombing threat: addition of detection markers to explosives for pre-blast detection, addition of identification taggants to explosives for post-blast identification of bombers, possible means to render common explosive materials inert, and placing controls on explosives and their precursors. The book makes several recommendations to reduce the number of criminal bombings in this country.

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