EPA Fine-Tunes Factory Fumes: Polyols Get Emission Overhaul
Published Date: 3/18/2026
Rule
Summary
The EPA is updating rules for factories that make polyether polyols, chemicals used in lots of products. These changes focus on cutting harmful ethylene oxide emissions, improving testing every five years, and switching to electronic reporting. The new rules start March 18, 2026, and will help protect the air while keeping industry on track without big cost surprises.
Analyzed Economic Effects
8 provisions identified: 0 benefits, 7 costs, 1 mixed.
Stricter EtO Process-Vent Controls
For process vents and storage vessels in EtO service, owners/operators must either route emissions through a closed vent to a non-flare control device that reduces EtO by ≥99.9% by weight or to a concentration less than 1 ppmv for each process vent/storage vessel, or route to a flare that meets new operating and monitoring requirements. As an alternative for process vents, the rule retains an option of an annual combined limit of 5 pounds per year for all combined process vents.
EtO-Specific Standards Finalized
The EPA finalized ethylene oxide (EtO) specific standards for the polyether polyols production industry covering process vents, storage vessels, equipment leaks, heat exchange systems, and wastewater. These EtO-specific standards are finalized under Clean Air Act section 112(d)(6) and the final rule is effective March 18, 2026.
Heat-Exchanger Leak Monitoring Tightened
Owners/operators must conduct quarterly monitoring for heat exchange systems (after an initial six months of monthly monitoring if not already done) using the Modified El Paso Method and repair leaks at or above 6.2 ppmv (as methane) of total strippable hydrocarbon concentration. For heat exchangers "in ethylene oxide service" (process fluids that are 1.0 percent or greater by weight EtO) the rule requires monthly monitoring and repairs as soon as practicable but no later than 45 days after receiving results, and repairs cannot be delayed more than 30 days if monitoring shows 62 ppmv or higher.
More Storage Tanks Now Need Controls
The rule lowers the Group 1 storage vessel size threshold so existing and new storage vessels between 38 cubic meters (10,000 gallons) and 151 cubic meters (40,000 gallons) with vapor pressure ≥ 6.9 kPa must add controls. The EPA also requires upgraded deck fittings and guidepole controls for all storage vessels equipped with an internal floating roof (IFR).
Tighter Monthly Leak Monitoring Rules
The EPA finalized more stringent leak monitoring for equipment in EtO service: connectors in gas/vapor and light liquid service and valves in gas/vapor or light liquid service must be monitored monthly at a leak definition of 100 ppmv with no reduction in monitoring frequency and no delay of repair. Light-liquid pumps must be monitored monthly at a leak definition of 500 ppmv.
Regular 5-Year Testing and Electronic Reporting
The final rule requires performance testing once every five years to show compliance with emission limits for certain process vents if emissions are routed to a control device other than a flare. It also requires electronic reporting via the EPA Central Data Exchange (CDX) using the Compliance and Emissions Data Reporting Interface (CEDRI) for performance test reports, flare management plans, and periodic reports.
EtO Wastewater Standards Finalized
The EPA finalized EtO-specific requirements that apply to wastewater from PEPO production as part of the EtO-specific standards covered under section 112(d)(6). These finalized wastewater provisions target emissions related to EtO in wastewater streams at PEPO facilities.
Rule Affects About 23 Facilities
As of December 1, 2025, the EPA identified 23 polyether polyol production facilities that are subject to the PEPO NESHAP and thus to these final amendments. If you operate one of these facilities, the finalized requirements (effective March 18, 2026) apply to you if your processes meet the NESHAP applicability criteria.
Your PRIA Score
Personalized for You
How does this regulation affect your finances?
Sign up for a PRIA Policy Scan to see your personalized alignment score for this federal register document and every other regulation we track. We analyze your financial profile against policy provisions to show you exactly what matters to your wallet.
Key Dates
Department and Agencies
Related Federal Register Documents
2026-06275 — Renewable Fuel Standard (RFS) Program: Standards for 2026 and 2027, Partial Waiver of 2025 Cellulosic Biofuel Volume Requirement, and Other Changes
The EPA just set new rules for renewable fuels in 2026 and 2027, including how much biofuel must be used. They’re also easing the 2025 cellulosic biofuel goals because production fell short and dropping renewable electricity as a qualifying fuel. These changes affect fuel producers and sellers, kick in mostly by mid-2026, and aim to keep America’s fuel cleaner and greener without breaking the bank.
2026-05167 — National Emission Standards for Hazardous Air Pollutants: Ethylene Oxide Emissions Standards for Sterilization Facilities Residual Risk and Technology Review Reconsideration
The EPA is proposing changes to rules for sterilization facilities that use ethylene oxide, a chemical that can be harmful if not controlled. They want to remove some strict risk-based limits, fix technical mistakes, and update how facilities prove they’re following the rules. If you run or work with these facilities, get ready for new deadlines and clearer standards by mid-2026, which could affect how you manage emissions and compliance costs.
2026-04646 — Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Large Municipal Waste Combustors Voluntary Remand Response and Five-Year Review
The EPA is updating pollution rules for big trash-burning plants to cut harmful emissions like lead, mercury, and dioxins. These changes affect both new and existing facilities, tighten limits, remove some loopholes, and improve reporting, all starting May 11, 2026. This update will help clean the air by reducing over 3,200 tons of pollution each year, making communities healthier and safer.
2025-21788 — Oil and Natural Gas Sector Climate Review: Extension of Deadlines in Standards of Performance for New, Reconstructed, and Modified Sources and Emissions Guidelines for Existing Sources
The EPA is giving oil and natural gas companies more time to meet new pollution control rules and report their emissions. Deadlines for fixing leaks, monitoring equipment, and submitting state plans are pushed back to help everyone get ready without rushing. These changes keep the climate goals on track while easing the financial and timing pressure on the industry.
2025-20402 — Updated Definition of “Waters of the United States”
The EPA and Army Corps are updating the rules that decide which waters are protected under the Clean Water Act, following a 2023 Supreme Court decision. This change helps everyone know exactly which waters are covered, making it easier to protect lakes, rivers, and wetlands while respecting state and tribal rights. People and businesses affected should share their thoughts by January 5, 2026, as this update could impact water projects and environmental protections.
2025-19882 — Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) Data Reporting and Recordkeeping Under the Toxic Substances Control Act (TSCA); Revision to Regulation
The EPA is updating rules for companies that make or import PFAS chemicals, asking them to report certain info about these substances from 2011-2022. The changes add some smart exceptions to ease reporting on things companies probably don’t know, saving time and hassle. Comments on the proposal are open until late December 2025, so affected businesses should get ready to weigh in!
Previous / Next Documents
Previous: 2026-05252 — Fisheries Off West Coast States; Coastal Pelagic Species Fisheries; Biennial Specifications; 2025-2026 and 2026-2027 Specifications for Pacific Mackerel
Starting July 1, 2025, and again in 2026, the government is setting new fishing limits for Pacific mackerel off the West Coast to keep the fish population healthy. If fishermen catch the set target amounts—8,143 metric tons in 2025-2026 and 9,448 metric tons in 2026-2027—the fishery will close to protect the stock. These rules help balance fishing fun with conservation and take effect April 17, 2026.
Next: 2026-05264 — Special Conditions: Textron Aviation Inc. (Textron) Model MU-300-10, 400, 400A Airplanes; Rechargeable Lithium Batteries and Battery System Installations
Textron’s MU-300-10, 400, and 400A airplanes are getting a safety upgrade with new rules for their rechargeable lithium battery systems powering emergency lights. These special conditions make sure the batteries meet tough safety standards that current rules don’t cover. The changes take effect March 18, 2026, and Textron plus anyone interested can send feedback by May 4, 2026.
Take It Personal
Get Your Personalized Policy View
Start a Free Government Policy Watch to see how policy affects your household, then upgrade to PRIA Full Coverage for year-round monitoring.
Already have an account? Sign in