EPA’s 2021 Listing of 1-Bromopropane as a CAA Section 112 Hazardous Air Pollutant Questions and Answers

This document is not legally enforceable and is not a rule or regulation, does not change or substitute for any law, regulati on, or any other legally

binding requirement. The answers and examples provided in this document are not site-specific and may not apply in all circumstances. EPA
re com mends that facilities work with their st ate, local, or Tribal air regulatory programs as necessary to evaluate any potential regulatory impacts.

EPA's 2021 Listing of 1-Bromopropane as a CAA Section 112 Hazardous Air Pollutant

Questions and Answers

U.S. Environmental Protection Agency
Office of Air Quality Planning and Standards
January 5, 2022

On December 22, 2021, the U.S. Environmental Protection Agency (EPA) Administrator Michael S.
Regan signed the final rule to add 1-bromopropane (l-BP)to the Clean Air Act (CAA) list of
hazardous air pollutants (HAP). This action was published in the Federal Register on January 5, 2022
[87 FR 393], The HAP list is provided in section 112(b) of the CAA, with amendments codified in 40
CFR part 63, subpart C. The addition of 1-BP 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.

This document is intended to provide initial guidance to stakeholders in the form of questions and
answers about some of the potential impacts of the addition of 1-BP to the HAP list.

The EPA expects to develop a rule in the near term that will address impacts, implications, and
requirements associated with the addition of a new HAP to the HAP list. This regulatory
infrastructure will be proposed for public notice and comment in 2022 and is expected to be
finalized in early 2023.

This document provides guidance to the EPA regional and state/local/tribal permitting authorities as
well as to potentially impacted industries and the general public on how the EPA intends to exercise
its discretion in implementing the statutory and regulatory provisions that concern the addition of
1-BP to the list of HAP under CAA section 112. The guidance is designed to implement national
policy on these issues.

The statutory provisions and the EPA regulations described in this document contain legally binding
requirements. This document does not substitute for those provisions or regulations, nor is it a
regulation itself. Thus, it does not impose legally binding requirements on the EPA, air permitting
authorities, or the regulated community, and may not apply to a particular situation based upon the
circumstances. The EPA and those agencies with delegated authority or approved programs retain
the discretion to adopt approaches on a case-by-case basis that differ from this guidance, where
appropriate. Any decisions regarding a particular facility will be made based on the statute and
regulations. Therefore, interested parties are free to raise questions and objections about the
substance of this guidance and the appropriateness of the application of this guidance to a
pa rticular situation.

The statements in this document are intended solely as guidance. This document is not intended,
nor can it be relied upon, to create any rights enforceable by any party in litigation with the United
States. The EPA may decide to follow the guidance provided in this document, or to act at variance
with the guidance based on its analysis of the specific facts presented.

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This document is not legally enforceable and is not a rule or regulation, does not change or substitute for any law, regulati on, or any other legally

1-BP Usage

A wide variety of industries may potentially be impacted by the listing of 1-BP as a CAA section 112
HAP due to potentially broad and widespread applications of this solvent. The primary use of 1-BP is
as a cleaning solvent, both in solvent cleaning machines and as an applied solvent (e.g., wipe
cleaning). In addition, 1-BP has reported uses in both the manufacturing process and the final
cleaning of metal and plastic rods and tubes. There may also be additional uses of 1-BP that are not
specified in this document.

Questions and Answers

Throughout the rulemaking process to review and ultimately grant the petitions to add 1-BP to the
list of HAP under section 112 of the CAA, the EPA has received questions from stakeholders
potentially impacted by this novel action. The most common questions and the EPA's answers are
provided in this document as initial guidance.

Emissions Calculations

1. When does 1-BP become a listed HAP?

The effective date for the listing is 30 days after the publication of the final rule in the
Federal Register. [Effective date: February 4, 2022]

2. When does a facility include 1-BP in a facility's potential to emit (PTE)?

A facility must include 1-BP in its PTE beginning on the effective date of the final rule.
[February 4, 2022]

3. What happens if including 1-BP in a facility's PTE causes the facility to become a major source
of HAP?

The facility will need to follow the title V requirements for major sources (see Title V
Permitting below). In addition, as a major source, the facility may need to comply with other
National Emission Standards for Hazardous Air Pollutants (NESHAP) (See Part 63 NESHAP
Applicability below).

Title V Permitting

4. When is a title V operating permit application or permit revision required?

A major source of HAP is a "part 70 source" subject to the permitting requirements for major
sources and must submit a timely permit application within 12 months after the source
becomes subject to the permit program, or on such earlier date as the title V permit authority
may establish. 40 C.F.R. 70.5(a)(1)

For example, a facility that was not previously subject to title V permitting because its PTE
HAP was below the major source threshold (i.e., less than 10 tons for any single HAP and less
than 25 tons per year for all HAP) before the addition of 1-BP to the HAP list may become a
major source of HAP emissions once 1-BP is included in its PTE HAP calculations.

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This document is not legally enforceable and is not a rule or regulation, does not change or substitute for any law, regulati on, or any other legally

5. Can a source that would otherwise become a major source because of 1-BP take action to
reduce its PTE to remain an area source?

Yes. A facility that would become a major source because of the inclusion of 1-BP as a HAP
can take action to reduce its PTE below major source thresholds.

For example, the facility could eliminate 1-BP use altogether or obtain a permit containing
enforceable restrictions to reduce its HAP PTE below the major source threshold. A source
should consult the appropriate regulations and confer with its state, local, or tribal
permitting authority regarding the procedures applicable to its situation.

Part 63 NESHAP Applicability

6. Is 1-BP regulated by any current NESHAP?

No. All current NESHAP were promulgated prior to the listing of 1-BP as a HAP. When the
Agency promulgated those NESHAP, 1-BP emissions were not considered in the standard-
setting process.

7. If a facility's classification has changed from area source to major source, due to the inclusion
of 1-BP in the facility's PTE, are there NESHAP rules that could be applicable to the facility?

Yes. If a facility becomes a major source because of the inclusion of 1-BP in the facility's PTE,
the facility should review all major source NESHAP standards for potential applicability.
All major sources must comply with all applicable NESHAP for major sources. This could
include broad source categories, such as the NESHAP for boilers or reciprocating internal
combustion engines.

8. If there is no change in a facility's classification due to the inclusion of 1-BP in the facility's PTE,
are there any new requirements that apply to the facility due to the 1-BP listing (i.e., for any
area source or for a major source that remains a major source)?

No. If the facility's classification does not change, there are no new requirements under any
NESHAP because the EPA has not yet set standards for 1-BP. As discussed elsewhere in this
document, there maybe other applicable requirements.

Enforcement

9. Will the EPA take enforcement against sources that fail to comply with the CAA obligations
resulting from the listing of 1-BP?

Facilities subject to the CAA requirements because of the addition of 1-BP have an obligation
to comply, and failure to comply could result in enforcement. As described in Question and
Answer 3, the EPA believes that the inclusion of 1-BP in a facility's PTE could result in a
change to the major source status of the facility. The EPA is aware of the circumstances and
equities created by the listing of 1-BP as a HAP and will consider such circumstances and

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This document is not legally enforceable and is not a rule or regulation, does not change or substitute for any law, regulati on, or any other legally

binding requirement. The answers and examples provided in this document are not site-specific and may not apply in all circumstances. EPA
re com mends that facilities work with their st ate, local, or Tribal air regulatory programs as necessary to evaluate any potential regulatory impacts.

equities on a case-by-case basis when determining the nature and extent of any potential
noncompliance with the CAA requirements.

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