Summary of CMAS Changes to Ethylene Oxide
The Chemical Manufacturing Area Sources (CMAS) rule now includes new requirements for Ethylene Oxide (EO). Under these updates, processes with EO levels above specified thresholds must implement tighter controls, enhanced monitoring, and stricter leak detection and repair (LDAR) protocols. Pressure relief devices, bypass systems, and storage vessels in EO service are all subject to more rigorous standards, with new performance testing required every five years to verify compliance.
Key Implementation Dates
- January 22, 2025: Proposed rule publication
- January 27, 2025: Deadline to request virtual public hearing
- March 24, 2025: Deadline for comments
- January 2026: Final rule expected (CD deadline)
- Early 2028: EO provisions compliance date
- Early 2029: Non-EO provisions compliance date
Important Note on Ethylene Oxide Health Effects
Ethylene Oxide (EO) is recognized as a potent carcinogen that can affect human health through chronic exposure. It is known to pose risks to the respiratory system and increase the likelihood of certain cancers. Given its volatile nature, even low-level EO emissions can contribute to health concerns in surrounding communities.
Summary of the El Paso Method
The “Modified El Paso Method” is a technique cited for measuring total strippable hydrocarbons (including EO) in heat exchangers. It involves sampling and analysis procedures designed to quantify volatile compounds potentially escaping into cooling water or ambient air. However, some facilities may find this method inapplicable due to unique process conditions or complex waste streams, so alternative approaches may be necessary to accurately assess and control emissions.