Effective February 4, 2022, the U.S. EPA has added the chemical 1-bromopropane (1-BP) to the national Hazardous Air Pollutant (HAP) list. This is the first time that the EPA has added a chemical to the Clean Air Act (CAA) list under section 112(b)(1) since 1990.


The compound 1-BP or n-propyl bromide (nPB), CAS #106–94–5, is a brominated organic colorless liquid that is insoluble in water but soluble in ethanol and ether. Common usage of 1-BP includes as a solvent in vapor degreasing, dry cleaning; electronic, metal, and precision cleaning operations; aerosols; adhesives; and as an intermediate chemical in the manufacture of pharmaceuticals and agricultural products. Also, 1-BP can be a replacement for traditional dry-cleaning solvents like perchloroethylene and 1,1,1-trichloroethene.


This substance is an air pollutant, that has emissions in ambient concentrations, causes bioaccumulation deposition that is known to cause or may reasonably be anticipated to cause adverse effects to human health or adverse environmental effects.



After evaluation and solicitation of data from petitioners and administrators and review of public comments on June 11, 2021, the EPA published an advanced notice of proposed rulemaking (ANPRM), to add 1-Bromopropane to Clean Air Act Section 112 HAP List.

At first, the Halogenated Solvents Industry Alliance (HSIA) and New York State Department of Environmental Conservation (NYSDEC) submitted petitions requesting that the EPA add 1-BP to the CAA section 112(b)(1) HAP list on October 28, 2010, and November 24, 2011, respectively. The EPA notes that in an action published on November 23, 2015, the EPA added the chemical by the name 1-BP to the Community Right-to-Know Toxic Chemical Release Reporting requirements.


Actions required

New requirements are yet to be proposed or promulgated by EPA for facilities using 1-BP. This final rule will amend 40 CFR part 63, subpart C, to add 1-BP to the list of CAA section 112 HAP.


Chemical facilities with 1-BP emissions should consider evaluating the effects of this new designation. The process likely requires the facilities to identify sources with 1-BP emissions; evaluate rules and regulations for 1-BP control that already exists, and update the required standards.


This Rule development most likely is followed by information requests from EPA for details of 1-BP emissions from affected facilities. Further actions from this development might require additional stack testing requirements, recordkeeping, or monitoring.


Furthermore, additional rule changes can impact compliance, it is better to review:

  • 1-BP emissions if determined delete its impact on HAP minor status for current minor sources.
  • Include 1-BP to the total HAP emission limits in state/federal air permits and update limit changes.
  • Incorporate 1-BP in current NESHAP compliance for total HAPs emissions in the current permit.
  • Looking in previously exempt process equipment/scenarios where 1-BP is emitted.


There is no specific period for promulgating standards for newly listed HAPs under CAA section 112(b)(1). At this time the implementation guidance is unclear, but Walden recommends to the facilities to be prepared for the changes if applicable by addressing the 1-BP emissions as mentioned.


For further contact information:

The final rule by EPA is effective on February 4, 2022. If you need more information about this or other environmental challenges, contact Walden to learn more.



  1. [See Docket ID No. EPA–HQ– OAR–2014–0471].
  2. https://www.govinfo.gov/content/pkg/FR-2022-01-05/pdf/2021-28315.pdf
  3. https://www.federalregister.gov/documents/2022/01/05/2021-28315/clean-air-act-section-112-list-of-hazardous-air-pollutant-amendments-to-the-list-of-hazardous-air