Final Risk Evaluation for 1-Bromopropane (1-BP)

In December 2022, EPA released a final revised risk determination for 1-bromopropane (1-BP) as a whole chemical substance. This final revision supersedes the previous condition of use-specific risk determinations in the 2020 1-BP risk evaluation (and withdraws the associated order under TSCA section 6(i)(1)). These chemical-specific changes are in accordance with the path forward for the first 10 risk evaluations under TSCA laid out by EPA in June 2021.

The final revised risk determination does not assume that workers exposed to 1-BP are always provided or appropriately wear personal protective equipment (PPE). The consideration of this information will be part of the risk management process. 

EPA determined that 23 out of the 25 conditions of use evaluated drive the determination that 1-BP presents an unreasonable risk of injury to human health under its conditions of use. Two out of 25 conditions of use do not drive the unreasonable risk: commercial and consumer use of 1-BP in insulation for building and construction materials, and distribution in commerce.

Read the Federal Register notice.

Read the final revised 1-BP risk determination.

Read the Response to Public Comments to the draft revised Unreasonable Risk Determination for 1-BP.

On this page:

Risk evaluation findings
Next steps and public participation
2020 risk evaluation and supporting documents

On other pages:

Risk Evaluation Findings

In December 2022, EPA released a final revised risk determination for 1-BP. The final revised risk determination finds that 1-BP presents an unreasonable risk of injury to human health under its conditions of use.

In the August 2020 risk evaluation, EPA reviewed the exposures and hazards of 1-BP and made risk findings on this chemical. This risk evaluation included input from the public and peer reviewers as required by TSCA and associated regulations. EPA considered relevant risk-related factors, including, but not limited to: the hazards and exposures, magnitude of risk, exposed populations, severity of the hazards, and uncertainties, as part of its unreasonable risk determination.

EPA determined that 1-BP, as a whole chemical substance, presents unreasonable risk to human health.

EPA assessed the impact of 1-BP on workers, occupational non-users, consumers, and bystanders to consumer use. 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. After reviewing these data, EPA determined that risk to workers, occupational non-users (workers nearby but not in direct contact with this chemical), consumers, and bystanders drive the whole chemical determination of unreasonable risk. Risk from 23 out of 25 conditions of use (including manufacturing (including import), processing, industrial and commercial use, consumer use, and disposal of 1-BP) drive the whole chemical determination of unreasonable risk to human health. Two out of 25 conditions of use do not drive the final revised unreasonable risk determination: commercial and consumer use of 1-BP in insulation for building and construction materials, and distribution in commerce.

The revised risk determination for 1-BP does not reflect an assumption that workers always and appropriately wear personal protective equipment (PPE), even though some facilities might be using PPE as one means to reduce worker exposure, or that there is widespread non-compliance with applicable federal standards. EPA understands there could be occupational safety protections in place at some workplace locations; however, 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’s chemical-specific Permissible Exposure Limits (largely adopted in the 1970’s) are described by OSHA as being “outdated and inadequate for ensuring protection of worker health,” because OSHA has not issued a chemical-specific PEL, as is the case for 1-BP, or because EPA finds unreasonable risk for purposes of TSCA notwithstanding existing OSHA requirements. The consideration of information on use of PPE, engineering controls, and other ways industry protects its workers, as potential ways to address unreasonable risk will be part of the risk management rule development process.

Next Steps and Public Participation

In July 2024, EPA proposed a risk management rule to address the unreasonable risk posed by 1-BP to human health. Learn more and submit a comment.

EPA hosted a webinar on August 28, 2024, about the proposed risk management rule. View materials from the webinar.

Stay up to date on additional opportunities for public participation. Just like the risk evaluation process, there will be opportunities for public comment as EPA works to propose and finalize risk management actions for 1-BP. You can stay informed by signing up for our email alerts or checking the public dockets at EPA-HQ-OPPT-2016-0741 and EPA-HQ-OPPT-2020-0471 at www.regulations.gov.

2020 Risk Evaluation and Supporting Documents

Below are the final revised risk determination, 2020 risk evaluation for 1-BP, non-technical summary, response to comments, and other supporting documents.

The discussion of the issues in the final revision to the risk determinations supersedes any conflicting statements in the 2020 1-BP risk evaluation and the response to comments document.

Read the Federal Register notice.

Final Risk Evaluation for 1-Bromopropane (1-BP)

Risk Evaluation Findings

Next Steps and Public Participation

2020 Risk Evaluation and Supporting Documents

Assessing and Managing Chemicals under TSCA