The US Environmental Protection Agency (EPA) recently finalized a ban under the Toxic Substances Control Act (TSCA) on most uses of methylene chloride (CH₂Cl₂). (Earlier post.) Methylene chloride, also known as dichloromethane and DCM, is a volatile chemical used in a wide range of industrial, commercial, and consumer applications such as adhesives, sealants, degreasers, cleaners, and automobile products.

In the automotive industry, methylene chloride is used as a solvent in the manufacturing process to create polycarbonates (PC). Polycarbonates are used to produce critical automotive safety components such as head lamps and automotive bumpers.

Automotive specialists also use a vapor methylene chloride in the degreasing process to remove oils and grease from car transistor parts, diesel motors, gasket removal and for prepping metal parts for a new gasket.

EPA said that since 1980, at least 88 people have died from acute exposure to methylene chloride, largely workers engaged in bathtub refinishing or other paint stripping, even, in some cases, while fully trained and equipped with personal protective equipment.

While EPA banned one consumer use of methylene chloride in 2019, use of the chemical has remained widespread. EPA’s final risk management rule requires companies to rapidly phase down manufacturing, processing and distribution of methylene chloride for all consumer uses and most industrial and commercial uses, including its use in home renovations.

Consumer use will be phased out within a year, and most industrial and commercial uses will be prohibited within two years.

EPA’s methylene chloride rulemaking also establishes worker protections under the nation’s premier chemical safety law. For a handful of highly industrialized uses, EPA has created a Workplace Chemical Protection Program. This workplace chemical protection program has strict exposure limits, monitoring requirements, and worker training and notification requirements that will protect workers from cancer and other adverse health effects caused by methylene chloride exposure.

Uses that will continue under the Workplace Chemical Protection Program are highly industrialized and important to national security and the economy. These are uses for which EPA received data and other information that shows workplace safety measures to fully address the unreasonable risk could be achieved. These uses include:

1. Use in the production of other chemicals, including refrigerant chemicals that are important in efforts to phase down climate-damaging hydrofluorocarbons under the bipartisan American Innovation and Manufacturing Act.

2. Production of battery separators for electric vehicles.

3. Use as a processing aid in a closed system.

4. Use as a laboratory chemical.

5. Use in plastic and rubber manufacturing, including polycarbonate production.

6. Use in solvent welding.

For uses of methylene chloride continuing under the Workplace Chemical Protection Program, most workplaces will have 18 months after the finalization of the risk management rule to comply with the program and would be required to periodically monitor their workplace to ensure that workers are not being exposed to levels of methylene chloride that would lead to an unreasonable risk.

In consideration of public comments on the proposal, EPA extended the compliance timeframe to give workplaces ample time to put worker protections in place. EPA also revised several other aspects from the proposal including ensuring the Workplace Chemical Protection Program applies to the same uses whether they are federal or commercial uses, establishing a de minimis concentration, and provisions to strengthen and clarify aspects of the Workplace Chemical Protection Program such as monitoring requirements.