This article was authored by Joshua Fine of Crum & Forster

[author: Joshua Fine, Crum & Forster]

Methylene Chloride – A Hazard to Public Health

Methylene chloride, also known as dirchloromethane [osha.gov], is a volatile, colorless liquid with a chloroform like odor. Historically, it has been used in various industrial processes, such as pharmaceutical manufacturing, metal cleaning and degreasing, paint stripping, and paint remover manufacturing. Human exposure to methylene chloride occurs through inhalation, ingestion and skin contact. While exposure to methylene chloride from consumer products either in a home or occupational setting leading to fatalities has been documented since 1947 [dcreport.org], United States agencies [ocf.berkeley.edu], such as the Consumer Product Safety Commission and the Environmental Protection Agency (“EPA”) refrained for years from thoroughly addressing the health hazard.

Humans may suffer from acute and chronic exposure [toxicfreefuture.org] to methylene chloride. Acute exposures to methylene chloride can cause death by heart attack or asphyxiation, as it transforms to carbon monoxide in the body and can cut off the oxygen supply to the heart, and at high doses, turns off the breathing center of the brain. In particular, fetuses exposed to high concentrations of methylene chloride may experience these nervous system effects, as carbon monoxide binds tightly to fetal hemoglobin. Chronic exposures have been associated with cognitive impairment, effects on attention, non-Hodgkin’s lymphoma, multiple myeloma, liver, kidney, and reproductive toxicity, and cancer of the brain, liver and lung.

Increasing Regulation of Consumer and Commercial Uses of Methylene Chloride

Methylene Chloride in Consumer Products

In 2017 [epa.gov], EPA estimated that 32,000 workers and about 1.3 million consumers use methylene chloride paint removers annually. In March 2019, EPA issued a final rule titled “Methylene Chloride; Regulation of Paint and Coating Removal for Consumer Use Under TSCA Section 6(a),” which proscribed the manufacturing, processing, and distribution of methylene chloride for consumer paint removal products but not the commercial sale or use of such products in the workplace. In April 2019, various environmental groups challenged this rule in the Second Circuit of the United States Court of Appeals, seeking to expand the prohibition to commercial uses.  In 2021 [law.justia.com], the court denied the petitions for review of the rule, in part, holding that the retailer distribution ban was a fair means for EPA to accomplish its goal of ensuring protection from the risks of methylene chloride consumer uses.

In a 2021 JAMA article, titled Assessment of Methylene Chloride–Related Fatalities in the United States, 1980-2018 [ncbi.nlm.nih.gov], a case series of 85 methylene chloride–related fatalities from 1980 to 2018, found that 75% of the deaths occurred from exposures on the job. In November 2022 [epa.gov], the EPA found that most uses of methylene chloride constitute an “unreasonable risk of injury to health,” and in 2023, the EPA proposed a ban of most uses of methylene chloride, which it adopted on April 30, 2024. The EPA’s final rule titled “Methylene Chloride; Regulation under the Toxic Substances Control Act (“TSCA”), which was issued on May 8, 2024 [epa.gov], and became effective as of July 8, 2024 [federalregister.gov], will prohibit the manufacturing, processing and distribution of the chemical for all consumer uses by May 5, 2025, and most of its industrial and commercial uses by April 28, 2026.

Methylene chloride is only the second compound, after asbestos, to be banned under the 2016 Amended TSCA. Exemptions to the EPA ban [epa.gov] include using methylene chloride as a laboratory chemical and as a raw material in the production of electric-vehicle batteries and climate-friendly refrigerant chemicals. EPA’s final rule [epa.gov] also creates strict workplace protections to ensure that workers will not be harmed by methylene chloride in its exempted uses, and requires records maintenance, and notification of its restricted uses to companies to whom the chemical is being shipped by manufacturers, processors, and distributors.

Methylene Chloride in Food

Both the food additive and color additive Delaney clauses [ncbi.nlm.nih.gov] of the Federal Food, Drug and Cosmetic Act prohibit a cancer-causing substance for use in food. However, to date, methylene chloride is still listed as approved for use in food. In late December 2023, the Environmental Defense Fund, Breast Cancer Prevention Partners, Center for Environmental Health, Environmental Working Group (EWG), and Lisa Lefferts, an environmental health consultant, filed a food-additive petition [federalregister.gov] and a color-additive petition [govinfo.gov] with the Food and Drug Administration (“FDA”) requesting revocation of its approval of four solvents, including methylene chloride, from use in food. On 1/11/24, the FDA published a proposed rule to ban several food additives including methylene chloride, which is used to decaffeinate coffee [cspinet.org], for which electronic or written comments were accepted through 3/11/24. Proponents of these petitions, such as the Center for Science in the Public Interest, have asserted that although exposure to solvents, such as methlyene chloride, may only present a small cancer risk they should be banned from use in food.  On the state level, California Assembly Bill 2066 [legiscan.com] calls for the Office of Environmental Health Hazard Assessment to conduct a study on the health impacts of the consumption of methylene chloride and to update its no significant risk level and its maximum allowable level of methylene chloride by January 1, 2026.

Chevron Deference’s Demise

There will likely be challenges to the EPA’s ban by various companies and industry associations.  Already, on May 10, 2024, two Texas based-paint companies, East Fork Enterprises Inc. and Houston-based Epic Paint Co., filed a joint petition the U.S. Court of Appeals for the Fifth Circuit to review the EPA’s methylene chloride rule Federal Rule of Appellate Procedure 15, the TSCA § 19(a), 15 U.S.C. § 2618, the Administrative Procedure Act, 5 U.S.C. §§ 701-706, and the Small Business Regulatory Enforcement Fairness Act, 5 U.S.C. § 611.  Subsequent to the filing of the joint petition, on June 28, 2024, the U.S. Supreme Court issued its decision in Loper Bright Enterprises v. Raimondo [supremecourt.gov] (“Loper Bright”), which ended the 40-year-old precedent of Chevron v. Natural Resources Defense Council [supreme.justia.com]. Under the Chevron doctrine, courts were to defer to agencies’ expertise to determine how ambiguous language relating to their work should be interpreted. In its stead, the Loper Bright decision requires courts to “exercise their independent judgment in deciding whether an agency has acted within its statutory authority,” and “not defer to an agency interpretation of law simply because a statute is ambiguous.” The U.S. Supreme Court’s overruling of Chevron may curtail the ability of agencies like the EPA and FDA to expand their regulatory authority, as their rules regarding methylene chloride endeavor to do, absent explicit authorization from Congress.

Future Litigation Involving Methylene Chloride

For now, should the EPA’s finalized methylene chloride rule be upheld, considering the number of workers and consumers that may experience acute or chronic exposure to methylene chloride, there is clearly potential for litigation due to methylene chloride exposures to grow exponentially.