Extremely hazardous substances (EHSs) can be released accidentally as a result of chemical spills, industrial explosions, fires, or accidents involving railroad cars or trucks transporting EHSs. They can also be released intentionally through terrorist activities, or inadvertently by improper storage or handling. Workers and residents in communities surrounding industrial facilities where EHSs are manufactured, used or stored, and in communities along the nation's railways and highways, are potentially at risk of being exposed to airborne EHSs during accidental or intentional releases.
The Twentieth Interim Report of the Committee on Acute Exposure Guideline Levels: Part A presents conclusions and recommendations for improving the National Advisory Committee (NCA) on Acute Exposure Guideline Levels (AEGL) documents for the various twenty-nine chemicals and chemical classes, among them being chloroacetyl chloride, butane, ethyl, and nitrogen mustards. In addition to providing advisory data, the interim report reviews the proposed AEGLs for scientific validity, completeness, internal consistency, and conformance to prior National Research Council guideline reports. The report reviews NAC's research recommendations and-when appropriate-identifies additional priorities for research to fill data gaps. Moreover, this all-inclusive report provides updated technical guidance for establishing community emergency exposure levels for extremely hazardous substances pursuant to the Superfund Amendments and Reauthorization Act of 1986.