The U.S. Environmental Protection Agency (EPA) has posted an advanced notice of proposed rulemaking for control of ethylene oxide emissions (EtO), which would update a 2006 final rule that declared no additional controls for EtO were necessary. However, the agency’s latest proposed rule makes note of several technological advances that allow for greater control of EtO, a fact that could drive a greater regulatory requirement for containment and destruction of EtO emissions at medical device sterilization plants.