In a proposed rule published May 3, 2023, the US Environmental Protection Agency (EPA) has moved for a ban on all consumer and most industrial and commercial uses of methylene chloride (aka dichloromethane). The new rule follows EPA’s October, 2022 unreasonable risk determination which found that exposure to the solvent can lead to adverse health effects including neurotoxicity, liver effects, and cancer from inhalation and dermal exposure.
Methylene chloride is used in a variety of ways including consumer uses such as aerosol degreasers and brush cleaners for paints and coatings, commercial applications such as adhesives and sealants, in industrial settings for chemical and pharmaceutical manufacturing, and as a laboratory solvent. According to an EPA fact sheet, methylene chloride use is estimated at over 260 million pounds per year in the United States.
Some uses of methylene chloride are exempt from the proposed ban, including laboratory use. Per the EPA “Laboratory settings are expected to be more conducive to the implementation of engineering controls such as fume hoods to ventilate vapors and adequately reduce overall exposure to methylene chloride consistent with the hierarchy of controls.”
Although not covered by the ban, laboratory use would be subject to a Workplace Chemical Protection Program (WCPP). The WCPP would be based on the OSHA Methylene Chloride Standard, but would limit occupational exposure to 2 ppm as an 8-hour time weighted average (TWA) and 16 ppm as a 15-minute TWA short term exposure limit (STEL). These limits are significantly lower than OSHA’s current 8-hour permissible exposure limit (PEL) of 25 ppm and 15-minute STEL of 125 ppm.
Employers would have one year after the finalization of the rule to comply with the WPCC, and they would be required to periodically monitor their workplace to ensure that employees are not being exposed to levels of methylene chloride that would lead to an unreasonable risk.
Stakeholders have until July 3, 2023 to submit comments on the proposed rule via docket EPA-HQ-OPPT-2020-0465 at www.regulations.gov. To submit a comment, first navigate to the docket and then click “Browse Documents” to view the proposed rule and then click on the “Comment” button to submit your comment.
For additional information on the proposed rule and how it may affect your organization, please email us at [email protected].
This blog was written by Beth Graham, Safety Partners’ Director of Quality, Research, and Training.
