Assessment of Potential Hazards Associated with 1-Bromopropane (1-BP)

The Environmental Protection Agency (EPA) has taken a significant step in addressing the potential risks posed by the chemical substance 1-bromopropane (1-BP). On December 22, 2022, the EPA finalized a rule to add 1-BP to the federal list of hazardous air pollutants (HAPs) under the Clean Air Act.

In a separate development, the EPA proposed a risk management rule to address the unreasonable risk posed by 1-BP to human health in July 2024. The final revised risk determination for 1-BP, released in December 2022, finds that the chemical presents an unreasonable risk of injury to human health under its conditions of use.

The risk to workers, occupational non-users, consumers, and bystanders drives the whole chemical determination of unreasonable risk. The primary health risks identified in the risk evaluation are developmental toxicity from short-term and long-term inhalation and dermal exposure to the chemical and cancer from long-term inhalation and dermal exposure.

The revised risk determination does not assume that workers exposed to 1-BP are always provided or appropriately wear personal protective equipment (PPE). Instead, it considers the use of PPE, engineering controls, and other ways industry protects its workers as potential ways to address unreasonable risk in the risk management rule development process.

Out of the 25 conditions of use evaluated, 23 drive the determination that 1-BP presents an unreasonable risk. The conditions of use that do not drive the unreasonable risk include commercial and consumer use of 1-BP in insulation for building and construction materials, and distribution in commerce.

The EPA assessed the impact of 1-BP on all relevant groups, including workers, occupational non-users, consumers, and bystanders to consumer use. Several risk calculators and exposure models support the final risk evaluation for 1-BP.

As the process moves forward, there will be opportunities for public comment as EPA works to propose and finalize risk management actions for 1-BP. To stay informed, you can sign up for email alerts or check the public dockets at EPA-HQ-OPPT-2016-0741 and EPA-HQ-OPPT-2020-0471 at www.regulations.gov.

It is essential to note that while the EPA has taken steps regarding 1-BP, there is no specific information about a proposed rule for the EPA's Risk Management Program (RMP) specifically for 1-BP. For the most accurate and up-to-date information about the finalization of any proposed rule under the EPA's Risk Management Program for 1-BP, it would be best to consult the EPA's official announcements or contact their office directly.

On a separate note, the Office of Environmental Health Hazard Assessment (OEHHA) in California is currently proposing No Significant Risk Levels (NSRLs) for 1-BP under Proposition 65, with public comments accepted until October 6, 2025. Additionally, the EPA published a proposed rule on 1-BP under the Toxic Substances Control Act (TSCA) on August 8, 2024.

[1] OEHHA. (2021). Proposed No Significant Risk Level (NSRL) for 1-Bromopropane (1-BP) Under Proposition 65. Retrieved from https://oehha.ca.gov/prop65/proposed-nsrls

[2] EPA. (2022). Final Revised Risk Determination for 1-Bromopropane (1-BP). Retrieved from https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/final-revised-risk-determinations-1-bromopropane-1-bp

[3] EPA. (2022). Final Rule: Addition of 1-Bromopropane to the List of Hazardous Air Pollutants. Retrieved from https://www.federalregister.gov/documents/2022/12/22/2022-28026/addition-of-1-bromopropane-to-the-list-of-hazardous-air-pollutants

[4] EPA. (2024). Proposed Rule on 1-Bromopropane Under the Toxic Substances Control Act (TSCA). Retrieved from https://www.federalregister.gov/documents/2024/08/08/2024-15489/proposed-rule-on-1-bromopropane-under-the-toxic-substances-control-act-tsca