EPA Releases Draft Revised Risk Determination for 1-Bromopropane for Public Comment

Released on July 20, 2022.

Today, the U.S. Environmental Protection Agency (EPA) released for public comment a draft revision to the unreasonable risk determination for 1-bromopropane (1-BP) pursuant to the Toxic Substances Control Act (TSCA) section 6(b). The draft revised risk determination proposes to find that 1-BP, as a whole chemical substance, presents an unreasonable risk of injury to human health under the conditions of use.

The 1-BP draft revised risk determination incorporates policy changes announced in June 2021 to ensure the public is protected from unreasonable risks from chemicals in a way that is supported by science and the law. EPA’s proposed revisions will ensure that, if finalized, the 1-BP risk determination better aligns with the objectives of protecting health and the environment under the amended TSCA.

1-BP is a volatile organic compound with a wide range of uses, including as a solvent in degreasing operations, spray adhesives and dry cleaning; as a reactant in the manufacturing of other chemical substances; and in laboratory uses. There are also a variety of consumer and commercial products that contain 1-BP such as aerosol degreasers, spot cleaners, stain removers, and insulation for building and construction materials.

EPA’s 1-BP risk evaluation identified adverse human health effects to workers, occupational non-users, consumers, and bystanders to consumer use from 1-BP, including developmental toxicity, from acute and chronic inhalation and dermal exposures to 1-BP. EPA also identified cancer as an adverse health human health effect of chronic inhalation or dermal exposures to 1-BP.

The draft revised risk determination for 1-BP does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE). This decision should not be viewed as an indication that EPA believes there is widespread non-compliance with applicable Occupational Safety and Health Administration (OSHA) standards. In fact, EPA has heard from industry respondents about occupational safety practices currently in use at their facilities. EPA will consider this information, as well as other information on use of PPE and other ways industry protects its workers, as potential ways to address unreasonable risk during the risk management process.

Not assuming use of PPE in its baseline exposure scenarios reflects EPA’s recognition that certain subpopulations of workers exist that may be highly exposed because they are not covered by OSHA standards, because their employers are out of compliance with OSHA standards, because OSHA has not issued a Permissible Exposure Limit (PEL) for the chemical substance (as is the case for 1-BP), because OSHA’s chemical-specific PELs (largely adopted in the 1970’s) are described by OSHA as being “outdated and inadequate for ensuring protection of worker health,” or because the OSHA PEL alone may be inadequate for ensuring protection of worker health.

As EPA moves forward with a risk management rule for 1-BP, the agency will strive for consistency with existing OSHA requirements or best industry practices when they are sufficiently protective, and EPA will propose occupational safety measures in the risk management process that meet TSCA’s statutory requirement to eliminate unreasonable risk of injury to health and the environment.

Overall, 23 of the 25 conditions of use EPA evaluated would drive the 1-BP whole chemical unreasonable risk determination. Removing the assumption that workers always and appropriately wear PPE in making the whole chemical risk determination for 1-BP would result in seven conditions of use in addition to the original 16 driving the unreasonable risk for 1-BP. Additional risks of cancer from dermal exposures would also drive the unreasonable risk to workers in six conditions of use; additional risks for  non-cancer effects from acute and chronic inhalation exposures would also drive the unreasonable risk to workers in two conditions of use; and additional risks for non-cancer effects and cancer from acute and chronic inhalation and dermal exposures to workers would also drive the unreasonable risk in one condition of use.

Two out of 25 conditions of use would not drive the unreasonable risk: the commercial and consumer use of 1-BP in insulation for building and construction materials, and distribution in commerce.

Separately, EPA is conducting a screening approach to assess potential risks from the air and water pathways for several of the first 10 chemicals, including 1-BP. For 1-BP, certain exposure pathways that were or could be regulated under another EPA administered statute were excluded from the 2020 risk evaluation. This resulted in the air exposure pathway not being fully assessed. EPA’s screening approach will identify if there are risks that were unaccounted for in the risk evaluation for 1-BP. While this analysis is underway, EPA is not incorporating the screening-level approach into this draft revised unreasonable risk determination. If the results suggest there is additional risk, EPA will determine if the risk management approach being contemplated for 1-BP will protect against these risks or if the risk evaluation will need to be formally supplemented or revised.

Note that EPA has not conducted new scientific analysis on 1-BP as part of today’s actions. The 1-BP risk evaluation continues to characterize risks associated with individual conditions of use to support any determination of unreasonable risk for 1-BP as a whole chemical substance and to inform risk management.

EPA will accept public comments on the draft revised risk determination for 30 days following publication in the Federal Register via docket EPA-HQ-OPPT-2016-0741 at www.regulations.gov.

Read the Draft Revised Unreasonable Risk Determination for 1-BP