AOEC Exposure Codes

The AOEC Exposure Code List was first developed in 1994, for use by AOEC members in order to help systematically identify both existing and emerging occupational and environmental health concerns (Hunting and McDonald, “Development of a Hierarchical Exposure Coding System for Clinic-Based Surveillance of Occupational Disease and Injury”, Appl. Occup. Environ. Hyg. 10(4), April, 1995). The AOEC is a non-profit, 501(c)3 organization and encourages open access to the information and resources it has developed.  Neither the AOEC exposure code list nor the asthmagen designations are considered an official document of any governmental agency.

A supplemental designation for asthmagens (indicated by an “A”) is included on the list. Formal criteria for the asthmagen designation were first established for sensitizer-induced asthma in 2002, and for irritant-induced asthma (Reactive Airways Dysfunction Syndrome (RADS) in 2008. These criteria were developed in collaboration with experts in occupational and pulmonary medicine. Both sets of criteria have been reviewed and approved by the AOEC Board of Directors and are posted as a updated and combined document.

The AOEC Exposure Code List includes substances that have been reported as asthmagens by experts in occupational asthma (Chan-Yeung M and Malo JL. Tables of Major Inducers of Occupational Asthma in Asthma in the Workplace, 2nd edit., eds. Bernstein IL, Chan-Yeung M, Malo JL, and Bernstein DI. New York: Marcel Decker, Inc.1999; 683-720.).

Review Process: Although not all of the substances reported to be asthmagens have yet been formally evaluated against the AOEC criteria, the AOEC has established an ongoing process to determine which exposures meet the criteria. Each year, several exposures are selected for review based on recommendations from AOEC members, asthma experts, industry representatives, or other stakeholders. Requests for reviews should be addressed to Katherine Kirkland at either 202-347-4976 or Determination of which substances will be reviewed in a given cycle will be made by the AOEC Board of Directors. These annual reports are available from the AOEC office by request.

Exposures designated with an “A” for asthmagen are further classified by which criteria they meet.  Exposures reviewed and meeting criteria for sensitizer-induced asthma are designated “Rs”; those reviewed and meeting criteria for RADS are designated “Rr”; those reviewed and not meeting either set of criteria are designated “R”. Substances that are generally accepted as asthmagens are designated “G”.

The AOEC Exposure Code List was developed as a tool to help clinicians. It does not replace the user’s obligation to assess each situation on its individual merits and to draw independent judgments. In particular, the asthmagen list is not exhaustive. It is likely that some exposures not yet designated as asthmagens are capable of inducing asthma. Furthermore, the AOEC asthmagen criteria do not reflect a specific exposure scenario which will alter the risk of asthma from a particular substance (e.g. encapsulated or airborne form, enclosed or open process, low or high concentration).

AOEC Coding System: Downloadable

The codes themselves, in table format, are available through the interactive look-up program.