Industry News: EPA Seeks comments about ETO Inhalation Carcinogenicity

The EPA recently published a request for public comments in the Federal Register “Notice of a Public Comment Period on the Draft IRIS Carcinogenicity Assessment for Ethylene Oxide. The comment period closes on 8/23/2013. The National Center for Environmental Assessment (NCEA), try part of the EPA’s Office of Research and Development has drafted a report titled “Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide” available on the ISIS website. The first draft of this report was released in September 2006, and was revised following public comments, the second issue has now made its debut. The report summarizes the available evidence of carcinogenicity of EtO in humans and estimated the risk of developing cancer to someone as a result of exposure to EtO.

The two main conclusions of the report are that:

  • The weight of evidence from epidemiological studies and supporting information is sufficient to conclude that ethylene oxide is carcinogenic to humans.
  • Total cancer risk based on human data?lymphoid cancer incidence and breast cancer incidence in females is 1.80 × 10-3.

The report explained that “The derivation of unit risk estimates, defined as the lifetime risk of cancer from chronic inhalation of EtO per unit of air concentration, for lymphohematopoietic cancer mortality and incidence and for breast cancer mortality and incidence in females, based on results of the recent analyses of the NIOSH cohort, is presented in the following subsections.”

In other words, a woman exposed to 1 ppm EtO for her lifetime has a 0.18% chance of contracting either breast or lymphoid cancer due to this exposure, i.e. on top of the risk of developing these or other cancers due to others reasons.

This report is 174 pages long and so the brief summary here does not do it justice and therefore anyone interested is advised to download and read the report and perhaps offer comments to the EPA..