EPA Ends Affirmative Defense for Polyether Polyols Producers

Published in the Federal Register on September 2, 2025 (90 FR 42323), the rule takes immediate effect and fulfills a consent decree requiring final action by September 10, 2025.

What is affirmative defense?
Affirmative defense was introduced between 2008 to 2014 as a safeguard for companies facing emissions exceedances caused by sudden and unavoidable malfunctions. If facilities could show they took the right corrective steps, they could avoid civil penalties. But this protection was short-lived. In NRDC v. EPA (2014), the D.C. Circuit ruled that only federal courts, not EPA, have authority to determine penalties under the Clean Air Act. Since then, EPA has worked to remove affirmative defense provisions from dozens of industry rules.

What does this rule change?
With the September 2025 action, polyether polyol producers lose this legal shield. Any emissions violation, whether during normal operations, startup, shutdown, or malfunction, can now result in civil penalties. EPA emphasizes that emission limits and reporting requirements have not changed, but the ability to pre-emptively avoid liability has been eliminated. Companies must now make their case in court if enforcement actions are brought.

Why does this matter?
Polyether polyols are essential feedstocks for polyurethane foams, coatings, sealants, and elastomers. Their production, however, involves hazardous air pollutants such as ethylene oxide and propylene oxide, which carry significant toxicity and health risks. By removing affirmative defense, EPA is ensuring that emissions standards apply at all times, closing what it considers a loophole that weakened accountability.

After September 10, 2025
For the roughly 23 U.S. facilities in this sector, the deadline signals a stricter compliance environment. Producers face greater liability risks, as malfunctions will no longer excuse violations. This is expected to push companies toward stronger monitoring, preventive maintenance, and investment in emissions-control technology. It also increases the likelihood of legal disputes, since penalty decisions will rest entirely with the courts.

In practice, the September 10 rule does not change the standards themselves, but it raises the cost of failure. The move brings the polyether polyols industry in line with more than two dozen other sectors where affirmative defense provisions have already been removed, underscoring EPA’s broader strategy of tightening air toxics enforcement.

Source: PUdaily

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