Notice of Adoption of Reference Exposure Levels for Ethylene Glycol Mono-N-Butyl Ether
Download Reference Exposure Levels for Ethylene Glycol mono-n-Butyl Ether (EGBE)
The Office of Environmental Health Hazard Assessment (OEHHA) is adopting revised Reference Exposure Levels (RELs) for Ethylene Glycol mono-n-Butyl Ether (EGBE) (CAS No. 111-76-2) for use in the Air Toxics Hot Spots program. RELs are airborne concentrations of a chemical that are not anticipated to result in adverse noncancer health effects for specified exposure durations in the general population, including sensitive subpopulations. The adopted RELs cover different types of exposure to EGBE in air: infrequent 1-hour exposures, repeated 8-hour exposures, and continuous long-term exposure.
OEHHA is required to develop guidelines for conducting health risk assessments under the Air Toxics Hot Spots Program (Health and Safety Code Section 44360(b)(2)). In response to this statutory requirement, OEHHA develops RELs for many air pollutants, including EGBE. The EGBE RELs were developed using the most recent “Air Toxics Hot Spots Program Technical Support Document for the Derivation of Noncancer Reference Exposure Levels” (OEHHA, 2008).
Draft documents for the EGBE RELs were released on August 14, 2015, to solicit public comment and were discussed at public workshops in Sacramento and Diamond Bar, California, during the subsequent 60-day public review period. The documents were revised to reflect public comments, and peer-reviewed by the State’s Scientific Review Panel on Toxic Air Contaminants (SRP) in March 2016, and again in December 2016 before being finalized.
The REL values for EGBE are as follows:
Acute REL (for a 1-hour exposure): 4700 µg/m3 (1000 ppb)
8-Hour REL (for repeated 8-hour exposure): 164 µg/m3 (34 ppb)
Chronic REL (for long-term exposure): 82 µg/m3 (17 ppb)
Please direct any inquiries concerning technical matters or availability of the documents to:
Dr. John Budroe, Chief
Air Toxicology and Risk Assessment Section
Office of Environmental Health Hazard Assessment
1515 Clay Street, 16th Floor
Oakland, CA 94612
E–mail: john.budroe@oehha.ca.gov