“Confusing Landscape” of Exposure Limits Complicates Decision Making during Chemical Releases

By Ed Rutkowski

Washington State Convention Center, Seattle, Wash. (June 5, 2017)—When Andrew Maier trains emergency responders, he always asks them two questions. First, can they name the exposure limits available for use during an emergency response; and, second, can they identify which of those limits is most relevant for a specific scenario?

As Maier explained at “Acute and Emergency Exposure Limits for Chemical Release Incidents,” an educational session at AIHce EXP 2017, very few responders can answer these questions, and their uncertainty indicates one area where industrial hygienists can play a vital role in emergency response situations.

“There is this confusing landscape of alternative values we have at our disposal as industrial hygienists,” said Maier, who is an associate professor at the University of Cincinnati. To help ensure a successful response, industrial hygienists must understand how the various levels were derived and intended to be used.

Several organizations and government agencies produce exposure limits for emergency response situations. The National Academies of Science, Engineering, and Medicine publishes acute exposure guideline levels (AEGLs), exposure levels below which adverse health effects are not likely to occur. AEGLs are applicable to emergency exposures ranging from 10 minutes to eight hours. EPA’s levels of concern, or LOCs, indicate the risk potential of a hazard. Other exposure limits intended for emergency responses include AIHA’s emergency response planning guidelines (ERPGs), NIOSH’s immediately dangerous to life or health (IDLH) values, and the temporary emergency exposure limits (TEELs) of the U.S. Department of Energy.

A typical response evolves over time, Maier said, and the exposure limit appropriate when responders first arrive at the scene of a chemical release may no longer apply as more information about the chemical becomes known and the industrial hygienist has the opportunity to observe effects, if any, of exposure on the responders’ health. Over time, as remediation of a chemical release proceeds and the risk of high exposures dwindles, industrial hygienists might adopt risk management actions more consistent with occupational exposures.

Maier encouraged attendees to familiarize themselves with free online tools in preparation for emergency responses. The National Library of Medicine (NLM) maintains Chemical Hazardous Emergency Medical Management (CHEMM), which contains information on medical management, decontamination, and toxicology for various agents. Users of the Wireless Information System for Emergency Responders (WISER), another NLM tool, can determine the possible identities of an unknown chemical by entering physical descriptions of an accidental release into a database. EPA’s Computer-Aided Management of Emergency Operations (CAMEO) stores and evaluates information necessary for developing emergency plans.

According to Maier, industrial hygienists should carefully read the documentation for various emergency levels so they can develop a framework for how different values apply to different parts of an emergency response.

“It’s really important to read the basis for these values if you’re going to be using them,” Maier said, “so you can apply them in an appropriate manner.”

Ed Rutkowski is editor in chief of The Synergist. He can be reached at (703) 846-0734.
View more Synergist coverage of the conference on the AIHce Daily page.