The U.S. Environmental Protection Agency (EPA) has proposed banning most uses of methylene chloride (dichloromethane) under the Toxic Substances Control Act (TSCA), which governs chemical policy in the United States. Dichloromethane is a widely used laboratory solvent used in a variety of products such as adhesives, sealants, degreasers and paint strippers. This is the second substance to be subject to risk management under the Tsca procedure established in 2016, after asbestos last year.
The EPA's proposal would ban the manufacture, processing, and distribution of methylene chloride for all consumer uses, ban most industrial and commercial uses, and establish strict workplace controls for the remaining uses.
Laboratory use of dichloromethane will be regulated under the program and will be subject to a workplace chemical protection program, not a ban. This move will limit occupational exposure to an average of 2 parts per million for eight hours and 16 percent for 15 minutes.
The EPA has identified the risk of adverse human health effects from inhalation and skin exposure to methylene chloride, including neurotoxicity and liver effects. The agency also found that long-term inhalation and skin contact with the substance can increase the risk of cancer.
In announcing the agency's proposal on April 20, EPA Administrator Michael Regan said the science of dichloromethane is clear and that exposure to it can cause serious health effects and even death, which is practical for too many families who have lost loved ones to acute poisoning.
According to the EPA, at least 85 people have died from acute dichloromethane exposure since 1980. Most of them were workers engaged in home renovation contracting work, some of whom were fully trained and wore personal protective equipment. The agency noted that many more people "experienced serious and lasting health effects, including certain cancers."
During the Obama administration, the EPA determined that methylene chloride paint remover posed an "unreasonable risk of health harm." In 2019, the agency banned consumer sales of such products, but was sued by public health advocates who argued that the rules did not go far enough and that tougher measures should be taken as soon as possible.
The EPA expects most of its proposed new changes to be fully implemented within 15 months, amounting to a ban on the use of an estimated 52 percent of annual production for TSA-compliant end-uses. The agency said that for most of the uses of methylene chloride it is proposing to ban, alternative products are typically available at a similar cost.
But the American Chemistry Council (ACC), which represents U.S. chemical companies, immediately hit back at the EPA, saying dichloromethane (dichloromethane sds) is an "essential compound" used in the production of many consumer products.
In response to the EPA announcement, the industry group expressed concern that the announcement "creates regulatory uncertainty and confusion" with existing dichloromethane exposure limits set by the U.S. Occupational Safety and Health Administration. ACC concluded that EPA had "not determined" the need for additional occupational exposure limits already established.
The lobby group also accused the EPA of failing to adequately assess the impact of its proposals on supply chains. The ACC warned that such a rapid scale of production cuts could have a significant impact on supply chains if manufacturers had contractual obligations that needed to be met, or if manufacturers decided to stop production altogether. This includes the pharmaceutical supply chain and specific safety-critical, corrosion-sensitive critical uses identified by EPA."