Ethylene oxide

CASRN 75-21-8

Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide (2011 Interagency Science Discussion Draft)

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On September 22, 2006, the draft Evaluation of the Carinogenicity of Ethylene Oxide (EPA/635/R-06/003) and the draft charge to external peer reviewers were released for external peer review and public comment. This draft was reviewed by EPA’s Science Advisory Board (SAB) and the expert panel’s final report was made available December 21, 2007. Since that time the Agency implemented the May 2009 IRIS assessment development process in which other federal agencies and the Executive Offices of the President are provided two opportunities to comment on IRIS human health assessments; Interagency Science Consultation (Step 3) prior to public comment/peer review and Interagency Science Discussion (Step 6b) following peer review. In July, 2011, the draft assessment incorporating the SAB recommendations (December 2007) was sent to other federal agencies and Executive Offices of the President as part of Step 6 of the IRIS process. Following the May 2009 process, all written comments submitted by other agencies will be made publicly available. Accordingly, the interagency comments for ethylene oxide and the interagency science discussion materials provided to the other agencies are posted on this site.

Note: After further consideration EPA has decided to undertake an additional peer review of the revised draft assessment on how the Agency responded to the SAB panel recommendations (December 2007), the exposure-response modeling of epidemiologic data, including new analyses since the 2007 external peer review, and on the adequacy, transparency, and clarity of the revised draft assessment.


U.S. EPA. Evaluation of the Inhalation Carcinogenicity of Ethylene Oxide (2011 Interagency Science Discussion Draft). U.S. Environmental Protection Agency, Washington, DC, EPA/600/P-03/007B, 2011.

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Ethylene Oxide (EtO) is a gas at room temperature used in chemical manufacturing and as a sterilizing agent for medical equipment and a fumigating agent for spices. Human exposure can occur in occupations involving contact with the gas in production facilities and in hospitals and facilities that sterilize medical equipment. EtO can also be inhaled by residents living near production or sterilizing/fumigating facilities.


Date Description
01-Apr 1984EPA released the Health Assessment Document for Ethylene Oxide (External Review Draft)(EPA-600/8-84/009A).
02-Jun 1985EPA published the Health Assessment Document for Ethylene Oxide (Final).
03-Dec 1998EPA begins work on new assessment of carcinogenicity of EtO.
04-Mar 2006Completion of internal EPA review of draft assessment of carcinogenicity of EtO.
05-Aug 2006Completion of external Federal agencies review of EPA's draft assessment of carcinogenicity of EtO.
06-Sep 2006EPA released the draft assessment for a 30-day public comment period. [Federal Register Notice September 22, 2006]
07-Oct 2006A 30-day extension is given for the public comment period. [Federal Register Notice October 12, 2006]
09-Nov 2006EPA released the draft EtO peer review charge and Memo to the Science Advisory Board (SAB) for their review.
10-Jan 2007Peer review meeting of the SAB (public meeting).
11-Dec 2007EPA's SAB issued a final report on the review of the draft assessment of EtO.
12-Jul 2011EPA initiated Final Agency review and Interagency Science discussion (step 6 of the IRIS process) of the draft assessment of EtO.
13-Jun 2012EPA conducted further Agency review of the revised draft.
15-Jul 2013EPA released a revised draft assessment for additional peer review and public review and comment (step 4 of the IRIS process). [Federal Register Notice Jul 23, 2013] The interagency science discussion draft of the assessment and related comments were made available from this site.


Following review by SAB and consideration of public comments received, the Agency will revise the draft assessment and send it back to Final Agency review and Interagency Science Discussion (step 6 of the IRIS process). Then the carcinogenicity assessment will be finalized (step 7 of the IRIS process) and placed on the IRIS database.

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