Regulation of Ethylene Oxide (EtO) Under the Federal Insecticide, Fungicide, and Rodenticide Act
Certain products containing EtO are considered pesticides under federal law because they can be used to kill viruses and bacteria. Pesticide labels, which are part of a pesticide registration and are legally binding under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), carry directions and precautions that define who may use a pesticide, as well as where, how, how much, and how often it may be used. Failure to follow the label is a violation of federal law.
EtO can be used as a pesticide to sterilize certain equipment, including some medical devices (like implants and surgical equipment) which cannot be sterilized using alternative methods such as steam or radiation due to lack of compatibility with certain materials. EtO is also used to sterilize some spices, certain dried herbs, and dried vegetables at commercial sterilization facilities in order to control food-borne pathogens such as Salmonella and Escherichia coli. Other registered uses of EtO include the sterilization of some museum/library/archival materials, cosmetics, musical instruments, and beekeeping equipment (a use only in North Carolina). These uses are minimal, and in most cases, EtO is no longer used for these purposes.
Regular exposure to EtO over long periods of time can pose cancer risks. EPA is working to mitigate these risks by reviewing and proposing updates to the registrations of EtO as a pesticide under FIFRA. This is part of registration review, a process EPA conducts for all currently registered pesticides every 15 years to ensure that products can carry out their intended function without creating unreasonable risks to human health and the environment. The actions below outline the steps EPA has taken to date.
Draft Human Health and Ecological Risk Assessment
In November 2020, EPA's Office of Pesticide Programs released the draft human health and ecological risk assessment for EtO. In April 2023, EPA released its response to public comments on the 2020 human health and ecological risk assessment.
- 2020 Draft Human Health and Ecological Risk Assessment
EPA’s Response to Public Comments on the 2020 Human Health and Ecological Risk Assessment (pdf)
Draft Human Health Draft Risk Assessment Addendum
In April 2023, EPA released a draft risk assessment addendum that provides additional information on cancer risks from EtO. The addendum does not present any revisions to the human health dietary risk assessment or the ecological risk assessment.
Proposed Interim Decision
In April 2023, EPA also released the proposed interim decision (PID) for EtO. The PID proposes measures that would mitigate EtO's risk to human health as quickly as possible.
Fact Sheet: Proposed Actions under FIFRA to Reduce Ethylene Oxide Risk (pdf)
Explanation of Risk Reduction Measures in Proposed Interim Decision
Comment Period for the Proposed Interim Decision
Upon publication in the Federal Register, EPA's proposed interim decision (PID) and draft risk assessment addendum will be available for public comment for 75 days. Once closed, EPA will review comments and make any necessary revisions to the proposed mitigation before continuing to the next step in the registration review process, which may involve publication of an Interim Decision.
To view all documents related to EtO’s registration review or to participate in the public comment process, visit docket EPA-HQ-OPP-2013-0244.
Risk Reduction Measures in Proposed Interim Decision
Termination of Certain Uses Where Alternatives Exist
EPA proposes to terminate the following use sites of EtO:
Beekeeping equipment (in North Carolina)
The Agency anticipates no impacts from the proposed cancellation of museum, library, and archival materials; musical instruments; and cosmetic uses. This is because EtO is no longer commonly used in these sites and there are alternatives that are widely available, such as freezing, anoxia (oxygen deprivation), and gamma irradiation.
Similarly, there is low to no impact expected from the proposed termination of the beekeeping equipment sterilization use in North Carolina (the only state with this registered use). Chemical, cultural, and mechanical controls can be used as alternatives to EtO to manage American foulbrood, a contagious disease that affects honeybees.
Additionally, EPA is using the public comment period for its proposed interim decision to gather information about which commodities depend on EtO sterilization for food safety. EPA will consider phasing out the use of EtO on commodities for which EtO use is not critical for food safety and for which alternative treatment methods are available.
Use Rate Reduction for Medical Equipment Sterilization
EPA proposes to lower the amount of EtO used per sterilization cycle for medical devices at sterilization facilities while continuing to meet FDA requirements for sterility assurance. It is the Agency’s understanding that many sterilization facilities sterilize medical devices using much higher concentrations of EtO than what is required for sterility assurance, often times double the necessary concentration.
Due to the risks posed by EtO, EPA proposes an EtO use rate of 500 mg/L. EtO use rate above this amount for sterility assurance would no longer be permitted as an allowable use of EtO pesticide products, and as such would be considered a misuse enforceable under FIFRA. EPA will collaborate with FDA to ensure that lower concentrations of EtO for medical device sterilization will still sterilize pathogens effectively. EPA will also collaborate with FDA to ensure this proposed measure is implemented within a reasonable compliance timeframe.
EPA is aware of some medical device manufacturers who have been able to reduce the amount of EtO needed to sterilize certain medical devices. EPA's proposal aims to make this reduced EtO concentration a nationwide requirement to ensure all workers are protected at commercial sterilization facilities.
Engineering Controls for Worker Protection in Commercial Sterilization Facilities
EPA is proposing to require engineering controls in facilities that use EtO to sterilize medical equipment and/or fumigate spices. EPA proposes to require the following measures to reduce exposure within these facilities:
Implementing an air pressure gradient so air flows from low-EtO concentration spaces to high-EtO concentration spaces;
Separating Heating, Ventilation, and Air Conditioning (HVAC) systems between offices and EtO sterilization areas to ensure there is no circulation of EtO in office spaces;
Ventilating EtO storage areas to reduce the amount of EtO in the air;
Automating the transport of sterilized materials and aerated materials to remove humans and human exposure from the transport process (EPA is aware of some facilities that already automate transport of sterilized materials); and
Implementing EtO sterilization chambers where the sterilization and aeration occur within the same chamber (known as “all-in-one processing”) to eliminate EtO exposure during product transfer. This requirement would be for facilities where pressure sensitive devices are not sterilized, because pressure-sensitive devices may be damaged or otherwise compromised by all-in-one processing (all facilities that use EtO to sterilize spices are currently required to utilize this design).
Some of these risk reduction measures have been successfully implemented in recent years in some sterilization facilities to reduce worker exposure. EPA’s proposal aims to enforce these measures to further protect all workers at EtO commercial sterilization facilities.
Additional Personal Protective Equipment in Commercial Sterilization Facilities
EPA proposes that a self-contained breathing apparatus or a supplied airline respirator be required for any tasks where there may be high levels of EtO exposure. This will mitigate potential inhalation exposure risks to workers involved in the EtO sterilization process.
Additionally, EPA is proposing unprecedented real-time monitoring of EtO using technology with a limit of quantification at or below 10 parts per billion (ppb) of EtO in the air, the lowest possible measurement technology can currently quantify in the workplace. If levels surpass 10 ppb, workers (including office workers) will be required to wear PPE.
Engineering Controls for Healthcare Facilities
EPA proposes to require healthcare facilities to implement engineering controls to reduce exposure to EtO, including:
Separating EtO sterilization spaces from other work areas to reduce the broader circulation of EtO;
Implementing negative air pressure in rooms containing EtO sterilization devices to ensure that air will not flow from the room with a higher EtO concentration through the rest of the healthcare facility;
Using abatement devices (i.e., equipment used to capture polluting substances) that will remove EtO from the exhaust air and reduce discharge to the environment; and
Discharging exhaust air from EtO sterilization devices through exterior ventilation stacks after passing through abatement devices to reduce the amount of EtO re-entrained into the building.
New Data Requirements for Commercial Sterilization Facilities
EPA will propose a requirement that registrants submit data on commercially available technologies that can monitor below 10 ppb in real-time, while also documenting other instruments that can quantify levels around 0.19 ppb. This would aid in EPA’s efforts to find real time technologies that can detect EtO levels closer to the level of concern of 0.19 ppb for workers.
Additionally, EPA is proposing that registrants submit worker monitoring data to EPA after the implementation of our proposed mitigations, including engineering controls and PPE. This would help EPA determine whether the mitigation measures sufficiently reduce worker exposure in commercial sterilization facilities.
Upon receiving these data, EPA intends to initiate the next round of registration review for EtO earlier than the mandated 15-year timeframe, including assessing these measures and incorporating additional protections based on advances in technology that occur.
For More Information
Learn more about EtO by visiting www.epa.gov/hazardous-air-pollutants-ethylene-oxide.