EPA Emissions Standards Proposal Would Reduce Regulatory Burdens

The Environmental Protection Agency in March formally proposed amendments to the National Emission Standards for Hazardous Air Pollutants for commercial sterilization facilities that use ethylene oxide, a chemical commonly used as a sterilant for certain foods and approximately half of all medical devices in the US each year.

The proposed rule would reduce regulatory burdens on sterilization facilities that use EtO, resulting in significant savings for regulated parties over the next two decades.

The EPA proposes rescinding Biden-era 2024 standards and revising other standards for EtO emissions. In additon, the EPA will solicit comments on whether the 2016 Integrated Risk Information System cancer risk value for low-level ethylene oxide exposure, implemented during the Obama administration, is scientifically supported and suitable for regulatory decision-making.

Commercial Sterilization Facilities

Pursuant to its authority under Clean Air Act section 112, the EPA issues standards for stationary sources that emit substances the EPA has designated as “Hazardous Air Pollutants,” known as NESHAP. Under the CAA, the EPA has designated 188 substances as HAPs.

Commercial EtO sterilization facilities are a category of stationary emissions sources that use sealed chambers to sterilize medical products with EtO, a CAA-listed HAP. The first NESHAP for this source category was promulgated in 1994 and amended in 2001.

CAA section 112 established a multi-stage process for developing standards for HAP emissions from stationary sources. The first step generally involves establishing technology-based standards that reflect the Maximum Achievable Control Technology (MACT) or a proper alternative. The second stage requires the EPA to conduct a review to identify and address residual risk and determine whether additional standards are required “to provide an ample margin of safety to protect public health” within eight years of the promulgation of the NESHAP. At least every eight years, the EPA is required to review and revise the NESHAP “as necessary” considering “developments in practices, procedures, and control technologies.”

The EPA completed a required residual risk and technology review for commercial sterilization facility sources in 2006, finding the amended 1994 standards were adequate to protect public health.

Biden Administration Rule

However, in 2022, the Biden administration EPA conducted a second RTR, including a second risk review under CAA section 112(f)(2), following the EPA’s 2016 IRIS risk assessment for EtO. That IRIS risk value sets an “unacceptable” risk concentration that is far below reported background levels of EtO in ambient air, reported levels of EtO produced by everyday activities, and reported EtO levels naturally created within the human body. The EPA argued that while CAA section 112(f) only requires a single risk review, the statute didn’t limit EPA’s discretion to conduct further reviews based on the 2016 IRIS risk assessment for EtO.

In 2024, based on the results of the second RTR, the EPA adopted revisions to the NESHAP for commercial EtO sterilization facilities, including additional risk-based emissions control and monitoring requirements.

Depending on the amount of EtO a sterilization facility uses, those additional emissions control requirements include increased control equipment efficiencies for emissions sources, permanent total enclosure requirements, continuous emissions monitoring systems, and additional reporting requirements.

On March 12, 2025, the Trump administration EPA announced that it’s reconsidering the 2024 rule.

Proposed Rule

This year, the EPA proposed the repeal of the Biden-era rule and emphasized EtO’s importance to the domestic supply chain for medical devices, as the chemical is the only method to effectively sterilize moisture- and heat-sensitive products without damaging the products. The EPA also cited stakeholder concerns about the feasibility of complying with requirements imposed by the 2024 rule.

In proposing to rescind the 2024 standards promulgated under CAA section 112(f)(2), the EPA asserts that the statute only authorized a single residual risk review, so the Biden administration’s second RTR was improper and the 2024 risk-based standards should never have been adopted.

The proposal also states that the 2016 IRIS risk value isn’t appropriate for setting emissions standards and acknowledges that “significant uncertainties regarding the magnitude of EtO’s carcinogenic potency particularly at low levels” are additional reasons to rescind the 2024 rule. The EPA proposes MACT-based revisions to the emissions control efficiencies required for sterilization facilities’ emissions sources based on CAA section 112(d)(5) or (6), rather than risk-based standards under CAA section 112(f)(2). The proposed MACT-based standards would:

• impose a uniform control efficiency for new and existing sterilization chamber vents and aeration room vents of 99.9% and 99.6%, respectively, at facilities using at least 10 tons of EtO per year
• impose a uniform 99% control efficiency for chamber exhaust vents at facilities constituting area sources regardless of the amount of EtO used
• set uniform control efficiency requirements within defined Group 1 and Group 2 room air emissions sources that differ based only on major vs. area source classifications
• remove the permanent total enclosure requirements imposed by the 2024 revisions.

In addition, the proposed rule would give facilities the option to demonstrate compliance using either annual performance testing and parametric monitoring or a continuous emissions monitoring system.

Implications

The proposed rule would reduce regulatory burdens on sterilization facilities that use EtO. The Trump administration estimates the proposed rule would result in $630 million in compliance cost savings over 20 years for this essential component of the medical products supply chain.

The administration further asserts increased security in the US medical product supply chain and increased national security by decreasing the probability of sterilization facility closures and the need to rely on other countries for properly sterilized medical products.

For example, the proposal imposes emissions control requirements based on MACT standards reflecting the maximum reduction of HAP emissions technologically achievable, rather than the regulatory risk-based requirements derived from the 2016 IRIS risk assessment for EtO.

The proposal also removes the federal requirement for expensive capital improvements such as permanent total enclosures to capture low-level room air EtO emissions from ambient air inside the facility.

Additionally, the proposed rule gives facilities more flexibility in demonstrating compliance by continuing to use performance testing and parametric monitoring.

However, the federal rule change wouldn’t necessarily affect state or local air regulations and permitting requirements, which may impose different and more stringent standards.

If the EPA adopts the proposed rule, regulated parties must remain aware of any state and local air regulations and requirements imposed in the 2024 NESHAP rule or other requirements in addition to those in the proposed rule.

The EPA hosted a virtual public hearing on April 1 and is accepting public comments through May 15. Interested stakeholders should engage in EPA’s ongoing public comment period and continue tracking rulemaking updates.

This article does not necessarily reflect the opinion of Bloomberg Industry Group, Inc., the publisher of Bloomberg Law, Bloomberg Tax, and Bloomberg Government, or its owners.

Author Information

Jeffrey Dintzer is a partner with Alston & Bird in Los Angeles representing companies in the energy, manufacturing, and defense industries.

Clay Massey is partner with Alston & Bird in Atlanta representing clients on complex litigation matters, particularly in the areas of toxic torts, environmental torts, and complex land use disputes.

Megan Couch is an associate with Alston & Bird in Los Angeles and focuses her practice on a range of commercial litigation matters.

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