Marking, Rendering Inert, and Licensing of Explosive Materials: Interim Report (1997)

The most recently compiled bomb threat data from the Bureau of Alcohol, Tobacco, and Firearms⁷ and Federal Bureau of Investigation (FBI)⁸ is shown in Table 1. The data for property damage and injuries in 1993 was significantly affected by the bombing of the World Trade Center in New York; the 1995 data was affected by the bombing of the Alfred P. Murrah Federal Building in Oklahoma City. For example, the bombing of the World Trade Center in 1993 caused $510 million in damage and resulted in 1042 persons injured—a significant portion of the 1993 data.

The most common materials used as ingredients in destructive devices in 1994 were reportedly flammable liquids (29%); various chemicals (26%); black powder (16%); photoflash/fireworks powders (16%); smokeless powder (9%); military explosives other than C-4 and TNT (1%); and dynamite/water gels, matchheads, blasting agents (including ammonium nitrate fuel oil, (ANFO)), and other fillers (2%). Ammonium nitrate fuel oil (ANFO), although used in a few highly publicized bombings, is not a frequently used ingredient. Significant amounts of information are now available on the Internet, compounding the bombing threat.