³ÉÈËÍ·Ìõ

As of May 2024, the EPA has designated methylene chloride as an unreasonable health risk under the Toxic Substances Control Act (TSCA). As a result of this ruling, all uses for DCM will be discontinued, with the exception of research. In order for a laboratory to continue working with DCM, initial and periodic exposure monitoring are required, along with a Workplace Chemical Protection Program (WCPP) and an Exposure Control Plan (ECP).

Under the new regulation, established occupational exposure limits (OELs) have been reduced to help protect users from the carcinogenic effects of DCM exposure. All labs that have or use DCM must be in compliance with this regulation.

Compliance Timeline:

Step 1: Elimination and Substitution

Labs are urged to discontinue use of DCM. Disposal and substitution are highly encouraged. 

Step 2: Workplace Chemical Protection Program (WCPP)

All researchers unable to eliminate methylene chloride must adopt a WCPP to limit lab occupant exposure. This plan must describe the exposure reduction measure(s) including but not limited to: 

1. Initial monitoring
2. Regulated area establishment
3. Exposure control plan
4. Respiratory protection and personal protective equipment (PPE)
5. Training
6. Periodic monitoring

Step 3: Exposure Monitoring

Exposure monitoring must be completed by May 5, 2025 or within 30 days of initial use.

Initial Exposure Monitoring

DCM users will be monitored for a full 8 hours using vapor monitoring badges or a series of activated charcoal tubes. The wearer should record their activity during the 8-hour monitoring window. Badges and tubes must be worn in the "personal breathing zone", usually on the lapel or lab coat pocket.

Periodic Exposure Monitoring

If initial monitoring is below OELs, periodic monitoring must be performed every 5 years. If levels are above the action limit of 1 ppm, respirators and additional monitoring will be required. 

Comparison of OSHA exposure limits with new EPA rule: