In April 2024, the EPA finalized a major update under TSCA that slashes the occupational exposure limit for methylene chloride—also known as dichloromethane—to just 2 ppm as an 8 hour TWA (Time Weighted Average) , and sets a sharp 15 minute STEL (Short Term Exposure Limit) of 16 ppm. It now falls under a rigorous Workplace Chemical Protection Program (WCPP), which includes mandatory exposure monitoring, regulated areas, exposure control plans, and more.
