Ethylene Oxide: Interim Registration Review Decision
Garth Conrad
MedTech Quality/Regulatory Executive | Change Agent | Risk Management Evangelist | Data Analytics Enthusiast
Environmental Protection Agency's (EPA) released the interim registration review decision for ethylene oxide (EtO), a pesticide used in medical sterilization and food processing. The EPA assessed human health and ecological risks, considering public comments and interagency collaborations with the Food and Drug Administration (FDA) and Occupational Safety and Health Administration (OSHA). The interim decision outlines risk mitigation measures, including use cancellations and reduced EtO concentrations, to decrease worker and bystander exposure. Appendices provide further detail on labeling changes, species assessments, and public comment summaries. The EPA aims to balance EtO's benefits with the need to reduce its associated risks.
The transition from the Proposed Interim Decision (PID), issued March 2023, to the Interim Decision (ID) for Ethylene Oxide (EtO) involved several key changes, with some measures being deleted or decreased, and others being added or increased. The ID reflects the EPA's response to public comments and further analysis.
Decreased or Deleted from the PID to the ID:
(1) Specific Engineering Controls: The PID proposed specific engineering controls for commercial sterilization facilities and healthcare facilities. However, the ID removed the requirement for specific engineering controls like ventilation or negative air pressure systems for commercial sterilization facilities. Instead, the ID allows facilities flexibility to choose the most appropriate controls to meet new exposure limits.
(2) Real-time Monitoring at 10 ppb: The PID proposed continuous, real-time monitoring at a level of 10 parts per billion (ppb) inside commercial sterilization facilities. This requirement was revised in the ID to require continuous stationary indoor air monitoring using systems that can reliably measure to 0.1 parts per million (ppm) or lower, with facilities choosing their monitoring systems. The EPA determined that the 10ppb limit was not feasible.
(3) Data Requirements for Monitoring Technologies: The PID proposed a data call-in (DCI) for data on commercially available technologies that can monitor below 10 ppb in real time. However, this requirement was removed in the ID because the EPA acquired sufficient information through the public comment period.
(4) Concentration Rate Limit of 500 mg/L for Existing Cycles: The PID proposed a use rate reduction through reduced concentrations for existing cycles of 500 mg/L or less, with a 5-year implementation timeframe. This specific concentration rate limit and timeframe for existing cycles was not included in the ID.
(5) Air Exchanges Per Hour: The PID included air exchanges per hour as a way to reduce worker exposure, but this was removed due to potential conflicts with the Office of Air and Radiation’s (OAR) EtO Commercial Sterilizers NESHAP.
Added or Increased from the PID to the ID:
(1) Time-Weighted Average (TWA) Occupational Exposure Limit: The ID introduced a new requirement for an 8-hour time-weighted average (TWA) occupational exposure limit, measured near the worker’s breathing zone. The ID mandates a reduction from the OSHA Permissible Exposure Limit (PEL) of 1 ppm to 0.5 ppm within three years, 0.25 ppm within five years, and 0.1 ppm within 10 years.
(2) Worker Monitoring Data Collection: The ID requires EtO registrants to collect worker monitoring data annually from their customers beginning six months after the ID label amendments are approved. Registrants may not continue to sell EtO products to customers who do not provide worker monitoring data to EPA.
(3) Recordkeeping Requirements: The ID specifies that facilities must maintain records of indoor EtO levels by room or area throughout the facility.
(4) Training Requirements: The ID includes training requirements that align with OSHA’s information about the acute and chronic health effects of EtO exposure. Training must include information on the health effects of EtO exposure, and must be provided at the time of initial assignment and annually thereafter to all workers.
(5) Phased Cancellation of EtO Use on Certain Food Commodities: While the PID discussed a phased-out cancellation for food commodities, the ID implements this by requiring registrants to submit requests to terminate the uses of EtO for museum materials, library materials, archival materials, cosmetics, musical instruments, and beekeeping equipment within 60 days. The ID also implements a phased cancellation for certain food commodities, with a focus on commodities for which alternative treatments exist.
Other important clarifications or changes:
(1) Flexibility in Mitigation: The ID emphasizes flexibility for facilities to meet the demand for sterilized medical devices and food while reducing worker exposure.
(2) Label Language Changes: The ID includes revised label language regarding the OSHA PEL. Label amendments are expected to be submitted within 60 days after the decision.
(3) Risk-Benefit Analysis: The ID explains that while a quantitative cost analysis is not required, the EPA does consider the economic, social, and environmental costs and benefits of EtO use. The agency weighs the benefits of EtO (like medical device sterilization) against potential health risks.
(4) Consideration of the OAR NESHAP: The ID considers the requirements of the Office of Air and Radiation’s (OAR) NESHAP for EtO commercial sterilizers and how those requirements interact with the mitigation measures under FIFRA.
(5) Endocrine Disruptor Screening Program (EDSP): The ID states that the agency will make an EDSP determination before issuing a final registration review decision. The PID also noted that the Agency will complete the EDSP before completing registration review.
(6) Endangered Species Act (ESA): The ID notes that while the Agency is working on its obligations under the ESA, the mitigation measures identified in the ID are expected to reduce the extent of environmental exposure and may reduce risk to listed species.
(7) Reevaluation: The ID states that the Agency will reevaluate this interim decision within 8 years.
In summary, the ID reflects a more refined approach to mitigating the risks of EtO, shifting from prescriptive engineering controls to performance-based exposure limits, emphasizing flexibility for facilities, and incorporating more robust worker monitoring and training requirements.