A revised risk determination finalized by EPA on Nov. 10 finds that methylene chloride “presents an unreasonable risk of injury to human health.” According to EPA, methylene chloride is used as a solvent in vapor degreasing and metal cleaning as well as an ingredient in sealants and adhesive removers. The chemical also has consumer applications such as adhesives, sealants, degreasers, cleaners, and automobile products that contain methylene chloride. Adverse human health effects from acute and chronic inhalation and dermal exposures to methylene chloride include neurotoxicity and liver effects, EPA notes. The agency also identifies risks for cancer from chronic inhalation and dermal exposures to the chemical. The severity and potential irreversibility of the health effects associated with exposures to methylene chloride prompted EPA to use its “whole chemical risk determination approach” for the chemical rather than making separate risk determinations for individual conditions of use. The revised risk determination differs from previous risk evaluations of methylene chloride in that it does not assume that all workers exposed to the chemical always or properly wear personal protective equipment. This “reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed” for a number of potential reasons, the agency explains in a press release. For example, some workers could have increased exposure if they are not covered by OSHA standards or if the OSHA permissible exposure limit alone may be inadequate for ensuring the protection of workers’ health, which EPA states “is the case for methylene chloride.” OSHA’s permissible exposure limit for methylene chloride is 25 ppm as an 8-hour time-weighted average, and its action level is 12.5 ppm. The PEL was lowered to 25 ppm from 500 ppm in 1997. In a regulatory review of its methylene chloride standard published in 2010 (PDF), OSHA found that the standard “[remained] justified and necessary in light of ongoing hazards and fatalities” and that it should continue with no changes. Methylene chloride is found in some products used to remove paint from bathtubs. In 2013, OSHA and NIOSH jointly issued an alert about the hazards of methylene chloride for bathtub refinishers. The agencies had identified at least 14 workers since 2000 who had died while using paint stripping agents containing methylene chloride for bathtub refinishing. The alert advised employers to provide adequate ventilation and respiratory protection for these workers. A study published in JAMA Internal Medicine in 2021 identified 85 fatalities linked to use of methylene chloride paint strippers between 1980 and 2018. Most of the deaths—87 percent—occurred in occupational settings. EPA intends to develop a risk management rule for methylene chloride. “[EPA] will strive for consistency with existing OSHA requirements or best industry practices when those measures would address the identified unreasonable risk,” the agency explains. “EPA will propose occupational safety measures in the risk management process that would meet [the Toxic Substances Control Act’s] statutory requirement to eliminate unreasonable risk of injury to health and the environment.” The agency’s revised risk determination is available online. For more information, see EPA’s press release and its risk management webpage for methylene chloride.

ASHRAE, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, announced in December that it will develop a national indoor air quality pathogen mitigation standard. The organization aims to finalize the new consensus-based, code-enforceable standard within six months. ASHRAE cites the recent convergence of the influenza, respiratory syncytial, and SARS-CoV-2 viruses as one reason for expediting development of its IAQ pathogen mitigation standard, which will provide guidance for jurisdictions and building owners. The standard will address design and operation; alternative paths with the goal of equivalent clean air; and testing, verification, documentation or commissioning, and periodic recommissioning. ASHRAE says it will gather a team of internationally recognized experts to develop the IAQ pathogen mitigation standard. For more information, read the news release. Other COVID-19 resources from ASHRAE are available on the organization's website.

New resources published by EPA are intended to raise awareness about the prevention of lead exposure during renovation, repair, and painting (RRP) projects in homes built before 1978, when lead-based paint was banned for residential use in the United States. The agency’s “Renovate Lead-Safe Media Kit” includes communications resources for those who work on pre-1978 homes and plan to film, document, or otherwise share their renovation projects with viewers, social media followers, and others. The media kit includes a fact sheet, sample public service announcement scripts, ideas for videos to promote lead-safe work practices, shareable social media posts, and a suggested shopping list. The materials discuss the risks of lead exposure during RRP projects and steps for reducing lead exposure during home renovation. They also promote the availability of contractors who are certified and trained in lead-safe work practices. The media kit is available on EPA's website.