Status of EPA Proposal to Delist Ethylene Glycol Butyl Ether (EGBE) as a Hazardous Air Pollutant As of February 2004
The Environmental Protection Agency (EPA) published on November 21, 2003 in the Federal Register (68 Fed. Reg. 65648) its proposal to delist ethylene glycol butyl ether (EGBE) from the Clean Air Act Amendments' (CAAA) list of Hazardous Air Pollutants (HAPs). An EPA decision to delist would mean that EGBE would no longer be subject to the CAAA's Maximum Achievable Control Technology (MACT) requirements, or its residual risk and other requirements. EPA received comments for 60 days after Federal Register publication. All but two short comments supported delisting. EPA is now in the process of reviewing the comments and developing a Final Rule.
The American Chemistry Council Ethylene Glycol Ethers Panel (ACC Panel) filed a petition in August 1997 showing why the available evidence indicated that EGBE should be delisted. EPA found the petition complete as of December 21, 1998, and sought comments on the petition on August 3, 1999 (64 Fed. Reg. 42125).
EPA is directed under the CAAA to delist HAPs if there are "adequate data on the health and environmental effects of the substance to determine that emissions, ambient concentrations, bioaccumulation or deposition of the substance may not reasonably be anticipated to cause any adverse effects to human health or adverse environmental effects," Section 112(b)(3)(C). The Federal Register proposal (available at http://www.epa.gov/airlinks/airlinks1.html) indicates the Agency has found the data on EGBE meets this standard.
EPA finds wide margins of safety (“Hazard Quotients”) between estimated maximum exposures and lowest toxicity effect levels. Specifically, EPA states maximum human exposures will be 16 to 50 times lower than the lowest level expected to pose any risk to human health. Thus, EPA concludes: “[W]e judge that the potential for human health and environmental effects [from EGBE] is sufficiently low to provide reasonable assurance that such adverse effects will not occur.”
EPA also notes that exposure estimates were “at least a factor of 2” higher than what the Agency expects would be the maximum individual exposure and “at least an order of magnitude” less than the Agency’s Reference Concentration (RfC) (the level below which the Agency does not expect any adverse health effects).
EPA also reviewed the numerous toxicity studies of EGBE. The proposal includes extensive Agency scientific interpretation of all the toxicity studies (including lifetime animal studies that investigated chronic effects including cancer). The Agency finds these data fully support its RfC for EGBE issued in 1999. EPA includes in the proposal its most recent interpretation of the NTP study of cancer in mice and rats and concludes that extensive data show that its 1999 RfC is “sufficient” to prevent cancer risk to humans.
For an historical perspective of the delisting petition, please review the Information Update on the Panel’s website (http://egep.org).
This information is brought to you by the member companies of the American Chemistry Council CHEMSTAR® Ethylene Glycol Ethers Panel: The Dow Chemical Company, Eastman Chemical Company, Equistar Chemicals, LP, and Shell Chemical Company. For more information, please call your supplier representative, or Dr. Susan A. Lewis, Manager of the EGE Panel at
(703) 741-5635 or by E-Mail: