On January 5, 2022, the U.S. Environmental Protection Agency (EPA) published a final rule to add 1-bromopropane (1-BP) to the Clean Air Act (CAA) list of hazardous air pollutants (HAP). The addition of 1-BP, also known as n-propyl bromide, is the first time the EPA has added a new compound to the HAP list since Congress provided the original HAP list in the 1990 CAA Amendments.

A wide variety of industries may be impacted by the listing of 1-BP, which is primarily used as a cleaning solvent in solvent cleaning machines or as an applied solvent (e.g., wipe cleaning). 1-BP also has reported uses in both the manufacturing process and the final cleaning of metal and plastic parts.

A facility must include 1-BP in its potential emissions (PTE) HAP inventory in construction permit applications beginning February 4, 2022.

A facility’s HAP classification may change from area source to major source, due to the inclusion of 1-BP in the facility’s PTE. There are currently no National Emission Standards for Hazardous Air Pollutants (NESHAP) standards that include 1-BP. However, if a facility becomes a major source because of the inclusion of 1-BP in the facility’s PTE, the facility could become major for other NESHAP categories such as the NESHAP for boilers or reciprocating internal combustion engines. In addition, the facility will need to follow the Title V permitting requirements for major sources.

A facility that becomes a major source due to this rule, and has actual HAP emissions below the major source levels, may be able to establish enforceable limits to reduce potential HAP emissions and remain a minor source. In this case, the DNR will work with the facility to determine how to establish federally enforceable limitations.

Actual emissions of 1-BP are not required to be reported in Title V or minor source emissions inventories until 2023, for the 2022 emissions year.

The final rule and supplemental information can be accessed here.

Under a separate action, EPA has begun work on an “infrastructure” regulation that will address compliance and implementation issues associated with the addition of 1-BP to the HAP list. EPA is expecting the regulatory infrastructure will be proposed in 2022 and finalized in early 2023.