CSS employee owners supporting the University of Kentucky have started sampling campus laboratories with high use of methylene chloride to assess levels of employee exposure. This effort is in response to the Environmental Protection Agency (EPA) issuing methylene chloride regulations under Section 6(a) of the Toxic Substance Control Act in the Federal Register on May 8, 2024. This regulation prohibits manufacturing, importing, processing, and distributing methylene chloride for all consumer use, and most industrial and commercial uses. The exception to this regulation encompasses 13 different areas, which includes research laboratories. However, with these regulations, EPA has a new occupational exposure limit, called an EPA existing chemical exposure limit (ECEL). The weight average (TWA) ECEL for the standard eight-hour period is 2 parts per million (ppm) with an Action Level of 1 ppm. If an exposure of methylene chloride is at the action level, then the worker needs to be put into a Workplace Chemical Protection Program. This plan outlines how to reduce the employee’s exposure.  The rule indicates that initial exposure monitoring should be done by May 5, 2025.

To date, CSS has completed sampling in five laboratories covering six different uses of methylene chloride. The data shows, as of now, that using the chemical fume hood correctly keeps the methylene chloride exposure below the action level. However, operations occurring outside the chemical fume hood, then exposures are at the Action Level or near the eight-hour TWA ECEL.   

The next steps are to finish the initial monitoring, as well as working with the laboratories using engineering control or substitutions (if possible) to reduce the exposure to methylene chloride. 

Visit EPA’s webpage to learn more about risk management for methylene chloride

See More CSS Insights

Artist rendering of NOAA satellite in orbit

Engaging in New and Emergent Satellite Technologies 

CSS employee owners (formerly Riverside employees) support the National Oceanic and Atmospheric Administration’s (NOAA) National Environmental Satellite, Data, and Information Service’s (NESDIS) Center for Satellite Applications and Research (STAR). STAR is the science arm of NESDIS, which acquires and manages the nation’s environmental satellites for NOAA. Satellite observations are critical to informing situational awareness and…

Studying Mesophotic Coral Health

Mesophotic coral can live at depths of 500 feet below the ocean surface. Even at this depth, some of the mesophotic corals in the Gulf of Mexico were affected by the Deepwater Horizon oil spill in 2010. Our coral scientists supporting NOAA’s National Centers for Coastal Ocean Science are studying the extent of this impact.…

Assisting With Maui Wildfire Recovery

As part of our support to U.S. Environmental Protection Agency (EPA) Region 9 Superfund Technical Assessment & Response Team (START)—for which we are subcontracted through Weston Solutions, Inc.—CSS employee owners have been on-site in three-week rotations to assist throughout the rigorous recovery process.