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IV Recommendations The Committee has reviewed federal ri sk assessment for hazards to public health, particularly for chemically induced cancer, and has presented its findings concerning the nature of r isk assessment ~ the nature and utility of risk inference guidelines, and the effects of alternative organizational arrangements on risk assessment. The Come mittee's review leads to the general observation that the process of risk assessment, as performed by and for fed- eral regulatory agencies, has been developing rapidly in recent years, both with respect to its scientific basis and with respect to the agencies' organizational arrange- ments. Change this rapid is bound to lead to m~sunder- standing about the use of risk assessment in regulatory policy-making, particularly if some misconstrue risk assessment to be a strictly scientific undertaking. Much of the criticism of risk assessment stems from dissatis- faction with regulatory outcomes, and many proposals for change are based largely on the unwarranted assumption that altering the administrative arrangements for risk assessment would lead to regulatory outcomes that critics will find less disagreeable. Because risk assessment is only one aspect of risk management decision-making, how- ever, even greatly improved assessments will not eliminate dissatisfaction with risk management decisions The Committee believes that the basic problem with risk assessment is not its administrative setting, but rather the sparseness and uncertainty of the scientific knowledge of the health hazards addressed. Reorganiza- tion of the risk assessment function will not create the data and underlying knowledge that assessors need to make risk assessments more precise. We hold that the most productive path to a solution has three parts: 150
151 · Implementation of procedural changes that ensure that risk assessments take full advantage of the ava~l- able scientific knowledge while maintaining the diverse organizational approaches to administration of risk assessment needed to accommodate the varied requirements of federal regulatory programs. · Standardization of analytic procedures among fed- eral programs through the development and use of uniform inference guidelines. · Creation of a mechanism that will ensure orderly, continuing review and modification of risk assessment procedures as scientific understanding of hazards improves. The Committee offers in the following pages 10 recomb mendations whose implementation it believes will meet these general objectives. IMPROVING RISK ASSESSMENT THROUGH PROCEDURAL CHANGES BECOMME:NDATION 1 Regulatory agencies should take steps to establish and maintain a clear conceptual distinction between assess- ment of risks and the consideration of risk management alternatives; that is' the scientific findings and policy judgments embodied in risk assessments should be explicitly distinguished from the political, economic, and technical considerations that influence the design and choice of regulatory strategies. Although the Committee concludes that risk assessment cannot be made completely free of policy considerations, it also believes that policy associated with specific risk management decisions should not influence risk assessment unduly. }risk assessment and risk management involve dif- ferent goals, kinds of expertness, and operating prin- ciples. The goal of risk assessment is to describe, as accurately as possible, the possible health consequences of changes in human exposure to a hazardous substance; the need for accuracy implies that the best available scientific knowledge, supplemented as necessary by ass~mp- tions that are consistent with science, will be applied. The ultimate aim of risk management is to evaluate trader offs between health consequences and other effects of specif ic regulatory actions; this evaluation includes the application of value judgments to reach a policy decision.
152 Experience shows the difficulties that can arise from a blurring of the distinction between the two elements. If risk management considerations (for example, the eco- nomic or political effects of a particular control action for a particular chemical) are seen to affect either the scientific interpretations or the choice of inference options in a risk assessment, the credibility of the assessment inside and outside the agency can be co~pro~ mised, and the risk management decision itself may lose legitimacy. Indeed, such consequences can flow from Me mere perception, as well as the fact, of such influences. Each regulatory agency should commit itself to safeguard- ing the distinction between the processes of risk assess- ment and risk management. One among several suggestions f or accomplishing this safeguarding is to restructure the formal organization, separating an agency's or program's risk assessment staff from its policy-making staff, pos- sibly by establishing a separate risk assessment unit outside the agency. The Committee does not, however, recommend that agencies use any particular organizational arrangement for risk assessment. One might surmise that separating the staffs would help to reduce the likelihood that risk management considerations will influence risk assessment, but our survey of agency structures provided no clear evidence that such an influence was related to the degree of administrative separation. Formal separation has disadvantages that must be b=1- anced against its value in maintaining a distinction between risk assessment and risk management. Risk assess- ment and risk management functions are analytically dis- tinct, but in practice they do--and must interact. Organizational arrangements that completely isolate risk assessors from regulatory policy-makers may inhibit impor- tant communication in both directions. For example, to complete risk characterization, risk assessors must know what policy options are to be used to calculate alterna- tive projected exposures, and new opt ions may develop as the risk management process proceeds. Moreover, direct communication with the risk assessors is desirable to ensure that the regulatory decision-maker understands the relative quality of the available scientific evidence, the degree of uncertainty implicit in the final risk assessment, and the sensitivity of the results to the assumptions that have been necessary to produce the assessment. Such separation could also impair the risk manager's ability to obtain assessments that are tamely and in a useful form. The advisability of organizational
153 separation hinges on comparison of its benefits and costs in particular agencies and programs. Because drawbacks are likely to be most pronounced in the case of extra-agency separation, the Committee does not believe that it is appropriate to remove the risk assessment function and place it in an organization com- pletely separated from the regulatory agencies, as is contemplated in the ALEC propose, and H.~. 638. This judgment is supported by the conclusion that the benef its of increased separation are uncertain and that the disrupt tion and confusion caused by reorganization could be considerable. Measures other than organizational separation can ensure the distinction between the assessment of risk and the consideration of risk management alternatives. These measures include the practice of preparing written risk assessments (Recc~endation 2), arranging for independent peer review (Recommendation 3), and adhering to uniform guidelines for risk assessment (Recommendations ~ through 9) . REC~DATION 2 Before an agency decides whether a substance should or should not be regulated as a health hazard, a detailed , and comprehensive written risk assessment should be ,, prepared and made ~ sh between the , scientific basis and the policy basis for the agenav's conclusions. . . Although agencies commonly perform risk assessments before they take regulatory actions, the written assess- ments that are prepared vary in coverage, amount of explanatory detail, format, and completeness to an extent that limits their use as instruments of communication. The Committee believes that the matters addressed are so important and the consequences so far-reaching that a written risk assessment should be prepared for every significant regulatory decision and that each should be clear, detailed, and comprehensive account of the analysis performed. A written assessment should describe the vol- u~e and weight of scientific evidence to help to clarify the scientific and policy bases for regulatory decisions. The written assessment should be made accessible to the public at a time and in a form that facilitates public participation in any attendant risk management decision.
154 The Committee believes that the requirement to prepare a written assessment imposes a salutary discipline that, for several reasons, will improve the performance of risk assessment. First, the requirement to prepare a compre- hensive written assessment will encourage the agency to explain how each component of the assessment was treated; that should minimize the likelihood that risk management considerations will, unnoticed, affect the outcome of the assessment. Second, a written assessment can help to distinguish the factual basis of a risk assessment from inferences drawn where there is a lack of scientific consensus; this distinction will facilitate scientific review of the risk assessment, document the scientific basis of the assessment for outside observers, and acquaint the regulatory decisions maker with the relative completeness of the scientific evidence. Third, it will aid communication among specialists working on different parts of the assessment. Fourth, Me existence of an explicit description should simplify the conduct of later assessments of the same chemical, if additional scat es' tific evidence comes to light or other regulatory programs review the same substance. Finally, written risk assessments will be useful to institutions that oversee regulatory agencies, notably Congress and those responsible for judicial review. It is important, however, that the format and scope of written assessments not become an independent basis for legal attack. Content and Form An agency s written risk assessment should set forth in detail the nature and quality of the relevant scientific evidence concerning the substance in question and should cover a,1 relevant components of risk assessment. It should reflect attention to any applicable guidelines relied on in interpreting the evidence, so that a reader can ascertain what inference options were used, and should describe the scienti fic rationale for any departures from methods prescribed in such guidelines. If the choice of inference options is not governed by guidelines, the written assessment itself should make e~licit the assume tions used to interpret data or support conclusions reached In the absence of data. The document should acknowledge gaps and uncertainties in available information.
An agency's written assessments are likely to prove most useful if they follow a consistent format, so that readers, once familiar with the format, can use them efficiently. We believe that each program or agency can establish a uniform structure for its written assess- ments, and we hope that similarity, if not uniformity, will be possible in written assessments prepared throughout the government. Actions Covered This recommendation is not intended to apply to the risk posed by every substance, use, or exposure that engages an agency' s attention. It is intended to apply to agency decisions concerning important human exposure to a hazard. Such decisions would include (but not be limited to) establishment of an occupational safety and health stan- dard by OSLO, cancellation },y EPA of the federal regis- tration of a pesticide to which there is widespread human exposure, and EPA promulgation of limits for an air or water pollutant. The categor ies of actions covered by this recommendation could be defined precisely only after detailed statutory analysis. EPA appears to have had satisfactory experience with the practice of classifying its regulations as ~major" (those with very large economic and other effects that require an extensive regulatory analysis and formal review by the Office of Management and Budget), ~significant" (a larger category defined by internal EPA criteria), and "minor" (a similarly large group of routine and technical actions). We suggest that EPA prepare a written assessment for every major and significant action, and we encourage other agencies to devise similar methods of identifying which regulatory actions require written assessments. An agency's decision to refrain from regulation can often have important consequences, both for health and for the economy, and such decisions should rest on accurate, objective assessments of risk. The denial of a petition to act on a chemical to which exposure is extensive is an example. When an agency is confronted with choosing between limiting exposures to a substance and taking some lesser action and there is serious dispute over the character or extent of the risk posed, a written assessment is advisable.
156 RECOMMENDATION 3 An agency's risk assessment should be reviewed by an independent science advisory panel before and major regulatory action or decision not to regulate. Peer review may be performed by science panels already established or authorized under current law or, in their absence, by Panels created for this Purpose. . of an agencies workload is substantial, a standing advisory Panel (or Panels) should be established to review its risk assessments otherwise, ad hoc panels should be established on a case-by-case basis. · Panel m-miners should be selected for their l scientific or technical competence. · The appointment of members should be the responsibility of each agency director, but nominations , from the public and scientific organizations should be , ;n~it=A unlay current law nreseribeS another Procedure. Panels should Provide to the referring agencies written evaluations evaluations should be available for Public inspection. . This recommendation endorses outside peer review of agency risk assessments.. Such review should contribute to the important distinction between risk assessment and risk management, because risk management information would be excluded from the review; should improve the scientific quality of the assessments through the process of criticism and response; and should increase the credi- bility of agency assessments. The practice of preparing written risk assessments will facilitate the review process. The peer review function that we visualize is already evident in some agencies. We believe that a single approach would not fit all contexts, but that any mech- anism for scientific peer review should meet the general criteria described below. Panel Form The review function we recommend could be performed effectively by an appropriately qualified standing panel of independent scientists that is responsible For reviews ing agency assessments of a particular class of hazards. Any agency program responsible for a large number of
157 compounds to which humans are exposed in large amounts seems to be an appropriate candidate for a standing scientific review panel, but some programs may deal with so few chronic health hazards that a standing panel is not warranted. The Committee specifically contemplates that the review function recommended here can be per- formed by panels already available to several agency programs. Panel Composition and Selection . Members of a scientific review panel should be selected for their competence in fields relevant to the assessment of risks of the kind being evaluated. In our judgment, employees of private business organizations, members of environmental groups, and government research or regula- tory agency employees should not necessarily be disqua}i- fied; but no panel members should be employees of the acenav whose rose assessments are ~~ vet ~ rev `~-c" ~ rev ~ _ 7 _ _ ~ should any members participate in the review of sup stances in which they or their employers have substantial economic or other interests or on whose resect my ~~ their employers have publicly taken a position. It is important to safeguard both the reality and the appea~- ance of complete objectivity for each review. We contemplate that, as is common for existing panels, the appointing official would be the head of the agency whose r isk assessments are to be reviewed. Such an arrangement could be thought to jeopardize a panel's independence from the agency, particularly in cases in which it is known which chemicals the panel will review. Accordingly, each agency should establish procedures for obtaining nominees for panel membership whose objectivity is ensured. For example, some current procedures call for agency selection of members from lists of nominees provided by the President of the National Academy of Sciences and by the Directors of the National Institutes of }realm and the National Science Foundation. We see no magic in any particular nomination process. The impor- tant objective is a process that, first, ensures that panel members are selected for their training and experi- ence in relevant fields; second, prevents the appointing official from forming a panel that will produce (or appear to produce) a predetermined result; and, third, operates expeditiously. We recommend that this process include an opportunity for members of the public to nominate persons for panel membership.
158 Panel Functions our recommendation contemplates that, in a typical case, the responsible agency Will have prepared a written assessment of the risk posed by a substance. The index pendent scientific panel would be asked to review that assessment for comprehensiveness, scientific accuracy, and consistency with any applicable risk assessment guidelines. If such guidelines are flexible, an impor- tant panel function will be to ensure that departures From the inference options favored by the guidelines are justified on scientific grounds. In performing this role, the panel should, if it desires, have access to all the data available to the agency, including those on which the agency's analysts relied, as well as the agency's written assessment. The pane' should subject the agency' risk assessment to such scrutiny as the members find necessary to satisfy themselves that it is, with or with- out revisions, as complete and objective as available data permit. The panel should provide a written evalua- tion of the agency risk assessments including recommend cations for revision, if appropriate. This evaluation should be available for public examination by the time the agency initiates public proceedings to alter hen exposure to the substance in question for example, when the agency issues a notice of proposed rule-mak~ng. Panel Agenda Independent review of agency risk assessments is c~eslgnea to ensure the integrity and quality of the scientific bases for regulatory decisions affecting }groan health. Therefore, the Committee recommends that every action, including a decision not to regulate, that requires a written risk assessment be available for independent scientific review. A scientific review pane1's agenda may also include risk assessments for other decisions of interest to panel members, or its review could be initiated after a request by a third party. In the latter case, panels should have the authority to decide whether or not to respond to such requests for review. In general, the Committee expects that the panels would exercise discretion in invoking their authority to review assessments for routine, minor actions.
159 Timing of Review Independent scientific review of agency risk assessments should occur before an agency commences the public process leading to regulatory action. The purpose is to expose the agency's initial assessment of the risk posed by a substance to expert scrutiny at a tome when review can influence the agency' s course of action. Experience suggests that agencies are less receptive to criticism of the basis of their actions af ter they have announced a proposed course of action. Furthermore, although index pendent review can some times forestall misguided regula- tory actions even after they are initiated, prior review of such actions may help to avoid serious damage to agency credibility and unnecessary costs to private interests that would be adversely affected by public proposals for regulatory action. We recognize an important exception to our general recommendation of preaction peer review. Several statutes expressly empower agencies to act in an emergency to curtail human exposure to a substance that poses a serious health risk. Agencies have also devised informal procedures to effect Immediate protection of humans exposed to dangerous substances in other contexts. Our recommendation is not intended to cast doubt on the legitimacy of such authority or to impede its appropriate exercise. When an agency concludes that a hazard warrants immediate regulatory action to limit human exposure, it should be able to take action consistent with existing law without first going through the review process that we recommend. Promptly thereafter, however , the agency should submit its written risk assessment for independent review in accordance with the procedures outlined here. Weight of Pane} Evaluation A scientific review panel's critique of an agency's risk assessment should not be binding; that is, the agency should not be obliged to revise ~ ts risk assessment if the panel regards it as deficient. Agencies have a responsibility to state the basis of their actions, and the authority for their actions must remain their own. Serious panel criticism, however, would in practice cause any agency at least to reconsider, and ordinarily to r evise , its ~ isk assessment. The agency should discuss any Important criticisms of its assessment in its proposed regulatory action, and its response to a panel's criti-
160 clams would be an appropriate subject for public comment, as well as a possible basis for judicial challenge to any final action. We believe that an important benefit of peer review occurs before the review begins: risk assessors who expect an assessment to be subjected to serious scrutiny by eminent qualified reviewers are likely to be more careful and clear about the use and limits of scientif Sac evidence. Federal Advisory Committee Act The Federal Advisory Committee Act imposes many salutary requirements on panels established to advise federal agencies, including notably the requirement that panel meetings be held in public. But the Act's requirement that new advisory committees be chartered by the General Services Administration imposes substantial delays and its requirement that panel meetings be announced in the Federal Register at least 15 days in advance can markedly slow a panel's work. Consideration should be given to modifying both requirements or exempting such panels from the Act, as Congress did for CPSC's Chronic Hazard Advisory Panels. RECOMMENDATION 4 When two or more agencies share interest in and iurisdic- - tion over a health hazard epae i~ ~ c~nd~e tor cegula- tion by them in the near term, a joint risk assessment should be Prepared under the auspices of Me National Toxicology Program or another aPuropr~ate organization. Joint risk assessments should be prepared Primarily bY scientific Personnel Provided by the agencies and assisted as necessary bv other Government scientists. 1 This recommendation endorses coordination in assessing the risks of chemicals that are likely candidates for regulation by two or more agencies. Although all the end uses of a substance may fall within the jurisdiction of one agency (such as FDA for a food additive), exposures occurring during production, transportation, and distri- bution usually are within other agencies' jurisdictions. Thus, chemicals that pose a hazard to human health are at least theoretically subject to regulation by two or more
161 federal agencies. The Committee agrees with proponents of the centralization of risk assessment responsibilities that the agencies involved should operate on the basis of a common assessment of the substance's risks. However, the Committee differs with respect to the method for achieving this end. Actions Covered , Our recommendation does not call for the performance of joint risk assessment In every instance in which a sub- stance potentially falls within the jurisdiction of two or more agencies; we limit our proposal to circumstances in which assessment by more than one agency is likely In the near future. This limitation has two rationales. First, substantial risk may be associated with routes of exposure of concern to only one agency. Onder such cir- c'~stances, it would be unreasonable to invest tome and resources to establish an interagency panel of scientists. Second, even if different types of exposure entail risks, a substance may legitimately rank low in priority for one agency and high for another. Placement and Procedures The approach we visualize is similar to that followed in 1980, when the Interagency Regulatory Liaison Group, at the suggestion of CPSC, sought the assistance of the National Toxicology Program to examine the carcinoge- nicity of formaldehyde. The Program formed an ad hoc panel that consisted entirely of gover.~ent scientists, including some from SPA, OSHA, and FOA. We suggest that the National Toxicology Program be the usual vehicle for coordinating preparation of joint risk assessments. The National Toxicology Program has been in operation for several years and, In the Committee's judg- ment, has performed capably as coordinator of federal toxicologic research. At has displayed an ability to command the service of the gover~ent's best scientists. And it has developed effective working relationships with the regulatory agencies, which have become accustomed to looking to it for assistance in evaluat ing substances that are candidates for regulation. We expect that suggestions for establishment of an interagency taste force to evaluate a hazard will come
162 from the interested regulatory agencies. The personnel assigned to assemble the relevant data and perform the assessment could include scientists from the interested regulatory agencies, including the initiating agencies, and scientists from government research organizations, such as the National Institute of Environmental Health Sciences, the National Cancer Institute, and the National Center for Toxicological Research. The Corny ttee recom mends that task forces follow the same guidelines used by the regulatory agencies. Joint risk assessments should be subjected to independent scientific review. For reasons presented in the discussion of Recommenda- tion 1, the Committee believes that such an ad hoc approach is preferable to creation of a centralized risk assessment body. IMPROVING RISK ASSESSMENT ~K013GE UNIFORM I~EP~:NCE: GtJIDELINE:S RECOMMENDATION 5 a_; ;_- ~l~;~-l into: should be developed for use of federal regulatory agencies in the risk assessment In the Committee's judgment, the development of uniform inference guidelines Is feasible and desirable. However, the Committee emphasizes that guidelines cannot provide a formula for automatically calculating risk from available data; case-by-case scientific interpretation will still be crucial, and risk assessments must reflect experts' characterizations of the quality of the data and of the uncertainty associated with the final assessment. Adherence to uniform guidelines has several advantages over ad hoc performance of risk assessments. Guidelines could help to separate risk assessment from risk manage- ment considerations, improve public understanding of the process, foster consistency, and prevent oversights and judgments Mat are inconsistent with current scientific thought. The development and application of guidelines would help to focus discussion by the public and tile scientific community on the generic issues of risk assessment, outside the some tomes charged context of particular regulatory decisions. Such discussion could stimulate research interest and lead to evolutionary improvement in the guidelines and thus in the quality of
163 risk assessment--improvement that would not occur if risk assessments were performed on an ad hoc basis. Guidelines also provide an efficient means to ensure the quality and relevance of data generated in new bioassay, epidemi o- logic, and other pertinent studies on the toxicity of particular chemicals, thus improving the scientific data base for future risk assessments of those chemicals. Guidelines can also help regulated parties to know in advance the criteria that agencies will apply in exalt ating substances. Industry would benefit if all federal agencies used the same guidelines. Furthermore, uniform federal guidelines could help to harmonize the current development of risk assessment methods by an increasing number of state programs. Uniform guidelines should be prepared for hazard identif ~cation, dose~response assessment, and risk char- acterization. Government-wi de guidelines for exposure assessment may be impractical, and this aspect of risk assessment is treated separately in Recommendation 9. The Committee is aware of several arguments to the effect that uniform guidelines could have adverse effects. We believe, however, that well-designed and carefully applied guidelines will minimize these disadvantages. PECOMME:NDATION 6 l The inference guidelines should be comprehensive' detailed, and flexible. They should make - distinctions between the science and PolicY aspects of risk assessment. Specifically, they should have the following characteristics: . Thev should describe al1 components ct_~a~4 identif ication, aose~reSPonse assessment, and ruse characterization and should require assessors to show that they have considered all the necessary components an each step. . They should Provide detailed Guidance on how each component should be considered, but Permit flexibility to depart from the General case if an assessor demonstrates that an exception is warranted on scientific ~rounds. · TheY should provide susc~f ic Guidance on components of data evaluation that require the imposition of risk assessment policy decisions and should clearly d ~ stinquish those decisions f rom scientif ic decisions.
164 . They should provide specific Guidance on how an a!::~P550r is ICY Dresent the results of the assessment and the attendant uncertainties. . Dist~nguishi no Science f rom Pol icy A frequent deficiency of agency risk assessments is the failure to distinguish between scientific and policy considerations i n risk assessment. Cr. tics contend that the results of risk assessment are often seen as scien- tific findings by regulators and the public, whereas in fact they are based in part on other considerations. The Committee believes that guidelines can lead to risk assessments that clearly delineate the limits of current scientific knowledge and the policy basis for choosing among inference options. Comprehensive and Detailed Nature Comprehensive, detailed guidelines are needed to delineate risk assessment as a process distinct from risk manage- ment. Comprehensive guidelines are those which address all components of risk assessment that are subject to generic treatment. Detailed guidelines are those which provide substantial supplementary scientific discussion of each component. Such discussion helps to reduce the possibility that analysts will misuse guidelines as cookbook instructions and helps analysts to anticipate special conditions for which particular inference options are appropriate or inappropriate. Broad statements of principle are inadequate, because they leave components undefined and may permit excessive discretion in particular cases. An explicit, comprehen- s Eve statement has the advantages of improving public understanding of government risk assessment and of assisting regulated parties to anticipate government actions. Another reason for specifying comprehensive, detailed guidelines is that they hold the greatest promise of preventing inconsistency within and among agencies. At numerous points in a risk assessment, different risk assessors may select different (but scientifically valid) inference options; guidelines should speci fically address each of these. A related advantage is an improvement in quality control that could occur if all assessors were
165 required to consider the broad range of issues addressed in such guidelines; that would decrease the likelihood that important considerations would be neglected or that uninformed judgment would occur. Flexibility Rigid guide- ]?he Committee espouses flexible guidelines. lines, which permit no variation, might preclude the consideration of relevant scientific information peculiar to a particular chemical and thus force assessors to use inference options that are not appropriate in a given case. Also, rigid guidelines might mandate the continued use of concepts that become obsolete with new scientif ic developments. Large segments of the sc ientif ic community would undoubtedly object to such guidelines as incompat- ible with the use of the best scientif ic judgment for policy decisions. Flexibility can be introduced by the incorporation of default options. The assessor would be instructed to use a designated (default) option unless specific scientific evidence suggested otherwise. The guidelines would thus permit exceptions to the general case, as long as each exception could be justified scientifically. Such justi- ficatzons would be reviewed by the scientific review panels and by the public under procedures described above. Guidelines could profitably highlight subjects undergoing relatively rapid scientific development (e.g., the use of metabolic data for interspecies comparisons) and any other components in which exceptions to particular default options were likely to arise. They should also attempt to present criteria for evaluating whether an exception is justified. Presentin the Results of the Assessment g Conclusions based on a large number of sequential, dis- cretionary choices necessarily entail a large, cumulative uncertainty. The degree of uncertainty may be masked to some extent when, in the final form of an assessment, risk is presented as a number with an associated measure of statistical significance. If they are to be most instructive to decision~makers, assessments should provide some insight into qualitative characteristics of the data and interpretations that may impute more or less certainty to the f inal results.
166 RECOMMENDATION 7 The process for developing, adopting, applying, and revising the recommended inference guidelines for risk assessment should reflect their dual scientific and . . . policy nature: · An expert board should be established develop recommended guidelines for consideration and adoption by regulatory agencies. The board's recommended guidelines should define the scientific capabilities and limitations in assessing health risks, delineate subjects of uncer- taintv, and define the consequences of alternative policies for addressing the uncertainties. · The expert board1s report and recommendations should be submitted to the agencies responsible for regulating the hazards addressed by the guidelines for their evaluation and adoption. The agencies, perhaps with central coordination, should, when possible, choose a preferred option from among the options that are consistent winch ~ = ~ ]~ =~ members of the public to comment. The process followed by the qoverrment for adoption of inference Guidelines should ensure that the resulting Guidelines are uniform among all responsible agencies and are consistently adhered to In assessing the risks of individual hazards. . . The resulting uniform guise nes should govern the performance of risk assessments by all the agencies that adopt them until they are re-examined and revised: they should not prevent members of the public from disputing their soundness or applicability in Particular cases. In short the guidelines should have the status . of established agency procedures, rather than binding regulations. The guidelines should be reviewed periodically with the advice and recommendations of the expert board. The ^~ - cat Fox r - =is:ina ~h`? guidelines. like the process for adoption, should afford an opportunity for comment by all interested individuals and organizations. Inference guidelines for risk assessment are based largely on science, but other considerations are involved in components with substantial scientific uncertainty. For these, the choice among inference options can have substantial policy ramifications. Thus, we recommend a
167 two-step process in which a board of experts recommends guidelines and provides scientific commentary on avail- able inference options and then the government adopts final guidelines based in part on the board's recommendations. The Board and Its Role The recommended guidelines should be developed by a congressionally chartered board of experts who are independent of regulatory policy-making. We describe this board, its placement, and other functions that ~t can serve in Recommendation 10. In genera, terms, the board should be permanent, should represent professional excellence on a national scale, and should have facil ity with issues that have policy ramifications. We see advantages in locating the board outside the government. The board's Cope is mainly scientific. It should define the components of risk assessment and describe the scientific basis for each. When it finds general scien- tific agreement on the proper inference option for a component, it should designate that option in a recomb mended guideline. When the board finds no general scientific agreement on the available inference options, ~ t should recommend against the use of options that are scientifically unsupportable and comment on the relative strength of the scientific support For the options that remain.* Agency Adootion The Committee envisions that the second step in the establishment of guidelines w'11 be in the hands of the *Some members of the Committee believe that the board should also be encouraged in such cases to recommend th e option that it judges to have the most scient~f ~ c support, as long as the board clearly indicates that such choice s are based on m~ers' informed scientific judgment, not on general agreement in the scientific community. Other Committee members believe that such recommendations would imply scientific certainty where none exists and thus would result in scientists' improperly recommending policy on the basis of their subjective judgments.
168 government. The choice of guidelines is, ultimately, the responsibility of duly elected or appointed public officials, and public review and comment on the proposed guidelines should be completed before they are adopted. The Committee emphasizes that, to be most useful, the final guidelines should prescribe default options for all components of r isk assessment. Thus, the second step should f urther limit the inference options available to the agencies, even for components In which the }board found that no single option could be chosen on scientific grounds. In that case, full consideration should be given to the board's comments on the merit of the science tragic support that is available for each option. It is important that the process result in ~ timely, uniform set of inference guidelines to be used by all agencies. We thus see advantage in coordination of the agencies' adoption of guidelines by a single, central authority such as the Office of Science and Technology Policy, or by a mechanism designated by Congress. The Committee believes that adopting the guidelines as established procedures, rather than as formal regu~a- tions, would have several important advantages: it would allow guidelines to be adopted and amended more easily; it would bind the agencies to adhere to the guidelines until they were reviewed and revised (thus fostering predictability and consistency--any agency's failure to comply with its own guidelines could be noted by index pendent scientific review panels and could be cited as grounds for interested parties' legal appeal of an associated regulatory decision); and it would permit members of the public to advocate new or alternative approaches to risk assessment. Joint risk assessments performed by interagency task forces should be governed by the guidelines that emerge f ram this process . Uniformitv The Committee has presented its case for uniformity in guidelines: consistency in the conduct of risk assessment reduces the appearance of unfair and inconsistent regular tory policies, improves przority-setting among regulators' programs, increases public understanding, and provides coherence for those subject to various regulatory author- ities. A frequent argument against government-wide gu~de- lines is that different agencies have statutory respond
169 sibilities that reflect different social policies and therefore require different approaches to risk assess- ment. This argument reflects a misunderstanding of the purpose of guidelines. An agency would remain free to incorporate whatever social judgments are embodied in its mandate when deciding whether and how to regulate. Such risk management choices can be made independently of and after the completion of a risk assessment. Thus, two agencies could use the same risk assessment of a sub- stance, but regulate it differently on the basis of statutory or policy criteria applied after risk assessment. Periodic Review The scientific basis of risk assessment is evolving rapidly. Guidelines must continue to evolve to accom- modate scientific innovations and theories. By their very nature, guidelines themselves will help to foster evolutionary improvements by defining generic principles of risk assessment and focusing debate and empirical research on these principles. Furthermore, new public perceptions of risk occur, and guidelines will evolve in response to these changes as well. For example, attitudes about the practicality of the outright elimination of carcinogenic risk as a regula- tory goal have changed in the last decade. New methods of quantitative risk assessment have developed, and public discussions have increasingly focused on that field. These changes can be expected to continue, so regular periodic review of guidelines appears to be essential. Such review should follow the same procedures recommended for the initial guidelines, including ultimate agency adoption af ter public comment. RECOMMENDATION 8 l The Committee recommends that guidelines initially be developed, adopted, and applied for assessment of cancer risks. Consideration of other types of health effects should follow. It mav not vet be feasible to draw up as complete a set of inference guidelines for some other ~ . health effects. For these, def fining the extent of science tif Sac knowledge and uncertainties and suggesting methods for dealing with uncertainties would constitute a useful f irst step.
170 The Committee believes that guidelines for carcinogenic rise assessment should be drawn up first both because cancer is perceived as a major public-health hazard and because there is considerable experience with carcinogenic Disk assessment from which to draw. Several guideline documents for carcinogenic risk assessment have already been produced, and review of these documents and of their history should provide a useful point of departure. Bowever, the other health effects that result from exposure to hazardous substances are equally amenable to prevention by regulatory action. Guidelines are desirable for these types of effects, which include mutagenicity, reproductive and teratogenic effects, neurotoxicity, and behavioral changes. Less information (and, in some cases, less knowledge of causal mechanisms) is usually available on these effects. In fact, In some situations where the knowledge base is less adequate than in cancer, stipulated methods for handling scientific uncertainty may be even more Important. Risk assessments for cancer are likely more frequently to engage the problems of evaluating data on exposure of experimental animals, whereas many other health effects will require greater reliance on epidemio- logic evidence. The Committee believes that the absence of guidelines for a health effect Is not a justification for agency failure to perform risk assessments or to regulate on a case-by-case basis. RECOMMENDATION 9 Agencies should develop guidelines for exposure assess- . meet. Because of diverse problems in estimating different ._ . means of exposure (e.q~, through food, drinking water, and consumer Products), separate guidelines mav be needed for each. Operating assumptions are needed to estimate exposures when direct measurements cannot be obtained. Examples of cases in which such estimates would be important are the projection of exposure to new chemicals and determination of the exposure reduction that would result from ~mplemen- tation of a particular control option. In Only a few narrow cases (e.g., food additives) have general guide- l~nes been developed for exposure assessment. Although they are no less impor ant than techniques for hazard identification and dose-response assessment,
171 exposure assess...ent techniques have not been the subj ect of major scientific debate and scrutiny. For example, if exposure were known more accurately, priority-sett~ng for testing new chemicals or for initiating regulation of one of a group of chemicals could be organized on a more rigorous basis; consideration of both the apparent potency and the estimated exposure would be factored into such decisions. Exposure assessment guidelines that are uniform across federal programs may not be feasible, because of the diversity or media that must be addressed and the large variation in exposures. Medium-specific exposure models (such as dispersion models for air, water, and soil) are used by programs in the agencies with various degrees of sophistication and validation. Each agency or each prom gram in an agency should develop mediumrspecific guide- lines to stimulate evolutionary improvement, increase consistency and predictability, and isolate the choice among inference options from inappropriate risk manage- ment considerations. Two or more programs that deal with a given median of exposure should use the same guidelines. Agencies should make their proposed exposure assess ment guidelines available for public comment and should subsequently issue final guidelines as established procedures. A CENTRAL BOARD ON RISE ASSESSME:NT }METHODS RECOMME:NOATION 10 The Committee recommends to Congress that a Board on Risk Assessment Methods be established to Perform the following f unctions: . Of risk assessment and to make explicit the underlying assl ~ tions and policy ramifications of the different inference options in each component of the risk assess- ment process. . . To draft and periodically to revise recommended inference guidelines for risk assessment for adoption and use be federal regulatory agencies. To study agency experience with risk assessment and evaluate the usefulness of the Guidelines. To identify research needs in the r isk assessment field and in relevant underlying disciplines.
172 To avoid possible misunderstanding of the role of the Board, the Committee stresses the limitations on proposed Board activities. The Board would not perform or review individual risk assessments, nor would it adjudicate dis- putes arising from regulatory actions related to specific substances. Thus, the Board as envisioned would not per- form functions contemplated by the ALEC proposal or H.R. 638. A central board of distinguished expert advisors is not well-suited to such day-to-day responsibilities. Furthermore, we believe strongly that it would be inappro- priate to remove such essential analytic functions from the responsible agencies and that it would be wasteful to duplicate agency activities. m e Board would make its contributions through discus- sion of contending scientific positions, preparation of recommended uniform guidelines, and fostering of advance- ment of the field. It would fill a need for a prestigi- ous, independent locus of activity for improving the understanding of generic issues in both the scientific basis and the federal practice of risk assessment. Current ad hoc approaches too often color debate on general issues with the implications for particular, often contentious, risk management decisions. We expect that Board activities would improve the scientific performance of the agency processes and, in conjunction with other mechanisms we recommend, achieve greater objectivity and consistency and better public unde~stand- ing of risk assessment. The Board would be the body to which agencies, agency review panels, and others would turn both for periodic recommendations of guideline revisions and for information on the evolving art of risk assessment. Board Functions - We foresee four major functions for the Board. The first two, scientific review and development of recommended guidelines, would pursue the process described above for ache initial generation of inference guidelines (Rec~en~ cation 7) . The deaf ting of guidelines by the Board would ensure that guidelines benefit from the best available scientific knowledge and judgment. After recommended guidelines for a particular health effect were prepared and referred to the agencies for review and adoption, the Board would probably find it useful to continue its activ- ity in the review of scientific developments relevant to risk assessment for that effect.
173 The Board's third function would involve observation of and research into federal experience with risk assess- ment generally and review or the usefulness of guidelines. A major purpose would be to acquaint the Board with ways of improving the guidelines in later periodic reviews. As a fourth function, the Board would identify the key scientif ic research needs in health risk assessment. Preparation of guidelines would put the Board in an ideal position to understand which of the many inference options needed to cover gaps in scientific understanding are most important and are amenable to study. The policy difficul- ties in regulating chronic health hazards can be resolved only if uncertainty in the scientific basis of assessments i s reduced. Board activities could take such forms as advising funding agencies on research priorities, c~mmis- s~oning survey papers to synthesize recent scientific findings, and sponsoring conferences or special publica- tions on particularly apt scientific questions or on matters that are important to risk assessment, but have been neglected by the scientif ic commune ty. In addition, the Board's experience would place it in an ideal posi- tzon to assess whether and how toxicologic research on part~cu' ar chemicals could be better tailored to the analytic needs of future risk assessors. For example, many current testing procedures were designed for the narrow purpose of hazard identification, and adjustments in these procedures could lead to more definitive dose- r esponse assessments. The Committee believes that the responsibilities of the Board could be discharged by a group of volunteer experts that convened monthly for 1-2 days. Organizational Placement The proper placement of the Board would be crucial to its prospects for success. There are four criteri a for identifying appropriate locations: professional excellence, facility with studies having substantial policy ratifications, permanence, and independence. Professional excellence is Important because the Board's recommended guidelines, as well as its other work, should be based on the best available science; the Board should be able to attract the best talent in the nation. Facility with difficult policy issues is ~mpor- tant because risk assessment is not a strictly scientific undertaking, and it would be crucial for the Board to
174 conduct its work competently and with full understanding of the policy process. Placement in a permanent, existing organization is advisable because the Board should be able to begin its work quickly and remain stable in order to conduct periodic revisions of guidelines. Independence is needed to provide credibility; work that is suspected of bias will not transcend the current atmosphere of dis- trust. We see advantages in placing the Board outside the government. In particular, the Board should be ante to draw on the widest poor OF Scientific ex~:Lu~ all - ~~- be restricted to government scientists; placement in the government might hinder the perception that the Board Is free from the policy orientation of the administration in power; and direct invol~r-~nent by the regulatory agencies themselves could detract from their ability to make regu- ~atory decisions while the guidelines were in preparation. The Committee has evaluated a number of possible organizational bases for the Board. The National Toxi- cology Program has had relevant experience with the c~imntifin Basis oF risk assessment, but it already has major responsibility for coordinating testing of chemi- cals of interest to regulatory agencies. The Congres- szonal Office of Technology Assessment is another possibility. Bowever, the governance of the Office of Technology Assessment by a board composed of members of _ Congress could prove a practical impediment to the production of guidelines. Guidelines would clearly have Policy ramifications that may be at variance with the established policy positions of OTA board members. The Office of Science and Technology Policy or the Office of Management and Budget could provide government-wide coordination; both are in the Executive Office of the President and are well positioned to ensure agency response and uniform implementation of guidelines and over Board findings. The major disadvantage of location in the Executive Office of the President is the lack of independence and, consequently, the greater likelihood of mixing scientific and policy considerations. All these organizations share the major drawback that they are in the goverrment. A specialpurpose national (or Presidential) co~is- sion on risk assessment methods could attract eminent scientists to service and could be designed to balance viewpoints, but would lack permanence and policy experi- ence. Professional societies constitute another class of possible candidates, but they generally have limited familiarity with policy studies. .
175 We conclude that the National Academy of Sciences- National Research Council meets the four criteria for placement. The ALEC proposal addressed the some general concerns that have occupied this Committee and concluded that the most appropriate locus for the central panel was in the NAS-N~C. Although we do not concur in the idea of centralizing the performance of risk assessments, the arguments presented by the AIEC propose' for the selection of the NAS-~RC are fully applicable to the question of the placement of a Board that would address generic scienr tific issues in risk assessment. We believe that the Board could best function under ~AS-N~ auspices, if the NAS-NRC agreed to provide them, and would be of great value In achieving many of the goals that we share with the authors of the ATEC proposal and of B.R. 638. Current NAS-N~C procedures for establishing, managing, and issuing study reports are appropriate for the prospective Board. Qualifications of Sobers We recommend that the Board consist of scientists with training and experience in the various disciplines involved in the process of risk assessment, including biostatistics, toxicology, epidemiology, environmental engineering, and clinical medicine. Other relevant fields--such as law, ethics, and the social sciences-- should be included to ensure due apprec cation of the policy context of Board activities. For the same reason, some members should have familiarity with regulatory programs. The nomination and selection of members should be in accordance with established NAS-NBC procedures. Service might be for staggered 3-year periods. Sunset Review The entire concept of the Board and its functions should be reviewed after approximately 6-8 years.