Methylene Chloride Rule
In May of 2024, the US Environmental Protection Agency (EPA) issued an update to the Toxic Substances Control Act known as the Methylene Chloride Rule. It effectively prohibits the use of Methylene Chloride (CAS 75-09-2) and Methylene Chloride containing materials. Methylene Chloride, also known as Dichloromethane, DCM or Methane Dichloride, is a volatile, colorless liquid and is used in laboratory processes, automotive products and paint removers. Despite its utility, Methylene Chloride poses serious health risks, including respiratory and central nervous system effects, liver toxicity, and increased cancer risk from prolonged exposure.
Prohibition for consumer uses goes into effect May 2025. Only specifically allowed uses, such as use as a laboratory chemical, will continue to be permitted. However, the new rule creates additional documentation, record keeping and air monitoring requirements that users will need to comply with in order to continue using Methylene Chloride as a laboratory chemical. In addition, the exposure threshold is lowered to 2 ppm, well below the current OSHA PEL of 25 ppm.
EHS is currently working to comply with these changes and issuing direct communications to groups with qualifying materials in their inventory. For groups who no longer want to have methylene chloride or these materials on hand, EHS is prepared to pick up and remove the material without charge. For Laboratory Groups wanting to continue to use Methylene Chloride, EHS will be implementing the following:
- Initial Air Monitoring: Initial air monitoring will be conducted by EHS to determine exposure levels of employees to methylene chloride. Laboratories correctly applying the guidelines and requirements of the Chemical Hygiene Plan, Methylene Chloride Standard Operating Procedures (SOP) and the Exposure Control Plan are expected to have no exposure. Results will be provided to affected employees within 15 days after EHS receives the sample analysis report and will be kept for a minimum of 30 years.
- Training: In addition to Laboratory Chemical Safety Training, SOP Review and documentation, and lab specific training, additional Methylene Chloride training will be given to laboratory personnel in groups who have Methylene Chloride. This training will be provided via SciShield/BioRAFT.
- Continuous Periodic Monitoring: Periodic monitoring will be conducted as directed by the rule, including when work practices are changed in the laboratory or upon introduction of new processes.
- Engineering Controls and Work Practices: If air monitoring results indicate that methylene chloride levels exceed the PEL, EHS will work with groups to implement engineering controls to reduce exposure. This could include ventilation systems, process enclosure, or equipment modifications. Changes in work practices may also be required to minimize exposure, such as limiting the time employees spend in high-exposure areas or altering the way tasks are performed.
- Personal Protective Equipment (PPE): Regardless of exposure levels, PPE must be worn as required when working with hazardous materials including Methylene Chloride. If exposure monitoring indicates that respiratory protection is required, EHS will consult with end users to determine how to utilize elimination, substitution, or engineering controls to reduce exposure to below the regulated exposure limits.
By adhering to these requirements, SDSU can better protect our employees and students from the potential health risks associated with methylene chloride exposure, ensuring a safer and healthier workplace. Additional resources can be found below and you can contact EHS with any questions or concerns.