On April 20, EPA announced a proposed rule that would ban most uses of methylene chloride, a chemical used as a solvent in vapor degreasing and metal cleaning as well as an ingredient in sealants and adhesive removers. Methylene chloride also has consumer applications in adhesives, sealants, degreasers, cleaners, and automobile products. Following last year’s proposed actions to ban chrysotile asbestos, the new EPA proposal regarding methylene chloride is the second to be issued through a new process that calls for the agency to evaluate and address the safety of existing chemicals regulated under the Toxic Substances Control Act, as amended by the Frank R. Lautenberg Chemical Safety for the 21st Century Act in 2016. The summary section of EPA’s proposed rule explains that methylene chloride “is acutely lethal, a neurotoxicant, a likely human carcinogen, and presents cancer and non-cancer risks following chronic exposures as well as acute risks.” EPA’s press release announcing the proposed rule states that at least 85 people have died from acute exposure to methylene chloride since 1980, and many more have experienced severe, long-lasting health impacts. The fatalities have largely been among home renovation contractors who, in some cases, were fully trained and wearing personal protective equipment. In addition to prohibiting the manufacture, processing, and distribution of methylene chloride for all consumer uses, EPA’s proposal would ban most of the chemical’s industrial and commercial uses. Manufacturers, importers, processors, and distributors would be required to notify companies that receive methylene chloride shipments about these prohibitions and to keep records. However, the proposed rule would allow some military, industrial manufacturing, and industrial processing uses of methylene chloride under what EPA describes as “a workplace chemical protection program with strict exposure limits to better protect workers.” Examples of uses EPA’s proposal would allow to continue include the processing of methylene chloride to produce chemicals related to efforts to limit climate change as well as specific uses required by the National Aeronautics and Space Administration, the Department of Defense, and the Federal Aviation Administration. According to EPA’s press release, the agency consulted with OSHA and considered existing OSHA requirements while developing the proposed worker protections outlined in the rule. The pre-publication copy of the proposal explains that the workplace chemical protection program would include requirements related to inhalation exposure concentration limits and exposure monitoring for certain continued conditions of use of methylene chloride. The program would also include an existing chemical exposure limit (ECEL) that EPA describes as “an 8-hour occupational inhalation exposure limit based on the point of departure of the endpoint that drives the unreasonable risk determination,” which in the case of methylene chloride is chronic non-cancer liver effects. EPA’s proposed ECEL for methylene chloride is 2 ppm as an 8-hour time-weighted average, and its proposed short-term exposure limit is 16 ppm as a 15-minute TWA. These limits are lower than OSHA’s permissible exposure limit for methylene chloride of 25 ppm as an 8-hour TWA and STEL of 125 ppm. The proposed rule may be read in the Federal Register. Stakeholder feedback was accepted during a public comment period that ended July 3. For more information, see EPA’s April 20 press release and the agency’s webpage on risk management for methylene chloride.

NIOSH is seeking employers who are interested in participating in a project intended to reduce workers’ exposure to metal fumes, particles, and gases during thermal spray coating (TSC) and associated activities. TSC processes are fast-growing technologies developing new specialized applications. However, little is known about exposure and potential health effects when performing these processes. NIOSH plans to assess exposures and respiratory abnormalities in workers using TSC technologies in various industries, evaluate control measures present in workplaces, and make recommendations to improve the work environment. Following inhalation exposure, respiratory health, and control measure assessments, NIOSH will meet with employers to discuss study results and develop intervention strategies. Participating employers can benefit by gaining knowledge about workplace factors and activities that influence exposures, as well as effective control measures. More information, including contact information for the project’s officers, is available in NIOSH’s flyer (PDF).

New CDC recommendations for improving ventilation in buildings urge owners and operators to aim for at least 5 air changes per hour (ACH) in occupied spaces and to upgrade filters to those rated MERV-13 or higher. The agency stresses the importance of good ventilation in maintaining healthy indoor environments and protecting building occupants from respiratory infections, including COVID-19. CDC’s guidance outlines basic as well as “enhanced" strategies for improving buildings’ ventilation, filtration, and air treatment systems. According to the agency, enhanced strategies are those that can help lower the concentration of viral particles in building air. In addition to delivering 5 or more ACH and upgrading filters, these strategies include setting a building’s HVAC system to circulate more air when people are inside; bringing in clean outdoor air by opening windows or doors and using exhaust fans; and using air cleaners with high-efficiency filters to filter air. CDC also recommends that building owners and operators consider installing UV air treatment systems and using portable carbon dioxide monitors to help assess whether indoor air is stale or fresh. CO2 readings above 800 ppm suggest that more fresh, outdoor air may be needed in a space, the agency says. These updates accompany changes to CDC’s monitoring strategy for COVID-19 following the end of the national public health emergency on May 11. Further details can be found on CDC’s pages on improving ventilation in buildings and ventilation in buildings.