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History of Acute Exposure Guideline Levels (AEGLs)

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Why AEGLs were created

The 1984 release of methyl isocyanate in Bhopal, India, resulted in over 2,000 deaths, and many others were irreversibly injured with damage to the eyes and lungs. The release was from one container of methyl isocyanate.

This and other accidental releases of highly toxic chemicals focused international attention on the need for governments to identify hazardous substances and help local communities deal with them. The AEGL Program was established to provide guidance for emergency preparedness programs and emergency responders by developing hazard level guidelines for accidental or intentional chemical releases of airborne chemicals.

In November1995, the National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances, comprising government and non-government scientists from the national and international arena, was established to identify, review, and interpret toxicology and other scientific data and to develop acute exposure guideline levels (AEGLs) for high-priority, acutely toxic chemicals.

The Committee’s work, which spanned 15 years, produced AEGLs that are used worldwide by government at all levels and the private sector for emergency response activities. This was a huge accomplishment: It precluded individual federal and state agencies and private industry from developing their own individual acute exposure guideline levels that may have resulted in publication and use of different values, potentially creating confusion and controversy.

Read more about the history of AEGLs.

Steps leading to the creation of AEGLs

In June 1993, the then National Academy of Sciences (now called National Academies) published, "Guidelines for Developing Community Emergency Exposure Levels for Hazardous Substances." With this methodology in hand, EPA developed the concept of a working committee and solicited support and participation from federal and state agencies and organizations in the private sector to establish a joint committee to develop exposure guideline levels.

The National Advisory Committee for the Development of Acute Exposure Guideline Levels for Hazardous Substances -- usually referred to as the AEGL Committee or the NAC/AEGL committee – was a federal advisory committee (FACA). It first met in June 1996, and discussed more than 300 chemicals and developed AEGL values for at least 273 of the 329 chemicals on the AEGL priority chemical list.

The last meeting of the NAC/AEGL Committee was in April 2010, and its charter expired in October 2011. Although the work of the NAC/AEGL Committee ended, the AEGL program continues to operate at EPA and works with the National Academies to publish final AEGLs.

During its operation, the NAC/AEGL Committee set the standard for a new and fruitful way to develop a single high-quality scientific product required by many federal and state agencies as well as private sector groups.

Key accomplishments of the AEGL Committee

  • Pooled resources from the public sector (federal, international and state agencies) and the private sector (academic, non-profit organizations, and private industry) that provided a high level of scientific validity
  • Gathered comprehensive data and used a broad base of scientific knowledge and expertise.
  • Represented a significant cross-section of scientists in toxicology and related fields from both the public and private sectors as well as the international community that fostered consensus.