Medical instruments laid out on a light blue surface

Ethylene Oxide Standards

Eth­yl­ene oxide (EtO) is a flam­ma­ble and high­ly reac­tive gas that is used in more than 100 facil­i­ties nation­wide to ster­il­ize med­ical instru­ments and oth­er prod­ucts. Chron­ic con­tact with EtO is asso­ci­at­ed with can­cer, repro­duc­tive effects and neu­ro­tox­i­c­i­ty. Emis­sions from facil­i­ties that use EtO are sub­ject to nation­al emis­sion stan­dards for haz­ardous air pol­lu­tants (HAP) under the Clean Air Act, which the Envi­ron­men­tal Pro­tec­tion Agency (EPA) is required to review every eight years.


The EPA last con­duct­ed a review of HAPs for com­mer­cial ster­il­iz­ers in 2006 and is now more than five years late in con­duct­ing the next required review.

  • Decem­ber 2019

    In Decem­ber 2019, the EPA pub­lished an advanced notice of pro­posed rule­mak­ing request­ing input as it con­sid­ers propos­ing a future rule­mak­ing address­ing EtO emis­sions from com­mer­cial ster­il­iza­tion facil­i­ties. The pro­pos­al seeks infor­ma­tion on avail­able con­trol tech­nolo­gies for reduc­ing EtO emis­sions and on devel­op­ments in prac­tices, mea­sure­ment, mon­i­tor­ing, and tech­nolo­gies for the con­trol of EtO from com­mer­cial ster­il­iza­tion facilities.

  • Feb­ru­ary 2020

    In Feb­ru­ary 2020, a coali­tion of eleven attor­neys gen­er­al led by Illi­nois Attor­ney Gen­er­al Kwame Raoul sub­mit­ted com­ments urg­ing the EPA to adopt stricter stan­dards for EtO emis­sions. In their let­ter, the attor­neys gen­er­al rec­om­mend­ed the EPA reduce EtO air emis­sions by at least 99.9 per­cent, cap­ture 100 per­cent of all gen­er­at­ed EtO emis­sions, con­duct all required emis­sions test­ing under actu­al oper­at­ing con­di­tions, mon­i­tor emis­sions con­tin­u­ous­ly, and require each facil­i­ty demon­strate that its emis­sion reduc­tion mea­sures reduce the pub­lic health threat to work­ers and local communities.