The U.S. Environmental Protection Agency (EPA) announced Nov. 10 that methylene chloride presents an unreasonable risk to worker health when evaluated under its conditions of use.
Exposure leads to neurotoxicity, liver problems, cancer
Methylene chloride is used as a solvent in vapor degreasing, metal cleaning, production of refrigerant chemicals, and as an ingredient in sealants and adhesive removers. Common uses include adhesives, sealants, degreasers, cleaners and automobile products.
EPA identified risks for adverse human health effects:
- not related to cancer, including neurotoxicity and liver effects, from acute and chronic inhalation and dermal exposures, and
- risks for cancer from chronic inhalation and dermal exposures.
Evaluated under whole chemical risk determination approach
In its revised risk determination, EPA used its whole chemical risk determination approach because:
- there are points where the chemical exceeds benchmarks for multiple conditions of use spanning most aspects of its lifecycle that could impact the health workers, occupational non-users, consumers and bystanders, and
- the health effects associated with methylene chloride exposures are severe and potentially irreversible (specifically cancer, coma, hypoxia, and death).
EPA determined that 52 of the 53 conditions of use evaluated drove the unreasonable risk determination, with the only one not presenting an unreasonable risk being distribution in commerce.
An assumption that workers aren’t wearing PPE
This new risk determination doesn’t reflect an assumption that workers always wear appropriate PPE, even though facilities may be using proper PPE as a means to reduce exposure.
According to EPA, this doesn’t mean the agency feels there is widespread non-compliance with OSHA standards.
The EPA news release notes, “(EPA) received public comments from industry respondents about occupational safety practices currently in use at their facilities and will consider these comments, as well as other information on use of PPE, engineering controls, and other ways industry protects its workers, as potential ways to address unreasonable risk during the risk management process.”
The agency acknowledges that there could be protections in place at some facilities, but its assumption that PPE isn’t used in its baseline exposure scenarios reflects recognition that certain subpopulations of workers exist that may be highly exposed because:
- they aren’t covered by OSHA standards because their employers aren’t compliant with those standards
- OSHA’s chemical-specific permissible exposure limits (PEL) are described by OSHA as being “outdated and inadequate for ensuring protection of worker health”
- OSHA’s PEL alone may be inadequate for ensuring protection of worker health.
Risk management proposal on the way
As it moves forward with a risk management rulemaking for this chemical, EPA said it will “strive for consistency with existing OSHA requirements or best industry practices when those measures would address the identified unreasonable risk.”
EPA is currently working on a risk management proposal for methylene chloride, in which it will propose occupational safety measures.