Health‐Based Emergency Guidelines

Abstract

Abstract Emergency health‐based limits were demanded worldwide following the Bhopal, India disaster in December 1984 when 30 tons of methyl isocyanate were released in an act of sabotage killing some 3500 residents. Prior to 1987, the only short‐term limits readily available were the NIOSH IDLHs which were used to assist workers in selecting respiratory protection. No guidance levels existed for the general public. In 1987, the American Industrial Hygiene Association sponsored the development of Emergency Response Planning Guidelines (EPRGs) as health‐based levels for the general public for a 1‐h exposure following an industrial accident, act of terrorism, or transportation incidents such as a train derailment or tanker truck traffic accident. Such incidents would be rare, perhaps once in a lifetime, and would present an exposure scenario in which the dispersion cloud would present an immediate threat to health for 1 h during which the public escape further exposure or shelter in place. EPA and other government agencies developed Acute Emergency Guidance Levels (AEGLs) from 1996–2011. No AEGLs are being developed, completed, or updated since 2011. For ERPGs and AEGLs, there are three levels of concern: Level‐3—threshold for lethality; Level‐2—threshold for incapacitation or irreversible toxicity; and Level‐1—threshold for mild toxicity or offensive odor. Acute inhalation toxicity data in animals provides important information for Level‐3, while incapacitation data and the onset in irreversible toxicity are important Level‐2 considerations. Irritation and annoyance data are important in setting Level‐1.