FACT SHEET
Proposed Amendments to Air Toxics Standards for Lime Manufacturing Plants
ACTION
•	On August 19, 2019, the US. Environmental Protection Agency (EPA) proposed to amend
the 2004 National Emission Standards for Hazardous Air Pollutants (NESHAP) for Lime
Manufacturing Plants.
•	EPA is proposing minor amendments to enhance the effectiveness of the rule by
improving compliance and implementation.
•	This proposed action would affect emission units covered under the current NESHAP
such as lime kilns, lime coolers and process stone handling operations.
•	EPA issued the air toxics standards for Lime Manufacturing Plants on January 5, 2004.
The rule applies to facilities that operate a lime manufacturing plant and are major
sources of hazardous air pollutant (HAP) emissions. The NESHAP does not apply to
sources located at pulp mills or beet sugar manufacturing plants.
•	Following a residual risk and technology review (RTR) conducted under the Clean Air Act
(CAA), with this action EPA is proposing to:
o Revise requirements for periods of startup, shutdown and malfunction (SSM) to
be consistent with recent court decisions; and
o Require electronic reporting of compliance reports, including performance tests.
•	EPA will accept comment on the proposed amendments for 45 days after publication in
the Federal Register.
RESIDUAL RISK ASSESSMENT
•	The CAA requires the EPA to assess the risk remaining after application of the final air
toxics emissions standard. This is known as a residual risk assessment.
•	Based on the completed risk assessment, available health information and associated
uncertainties, EPA determined risks from the Lime Manufacturing source category are
acceptable and provide an ample margin of safety to protect public health.
•	The maximum lifetime individual cancer risk for inhalation for the source category is
estimated to be 1-in-l million.
•	Chronic inhalation cancer risks for actual and allowable emissions were all below a
hazard index of 0.4.
TECHNOLOGY REVIEW
•	The CAA requires EPA to assess, review and revise air toxics standards, as necessary,
taking into account developments in practices, processes and control technologies. The
technology review of the standards for lime manufacturing plants did not identify any
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technological developments that would further reduce HAP emissions beyond the
original NESHAP.
BACKGROUND
•	The CAA requires EPA to regulate toxic air pollutants, also known as air toxics, from
categories of industrial facilities in two phases.
•	The first phase is "technology-based," where EPA develops standards for controlling the
emissions of air toxics from sources in an industry group or "source category." These
maximum achievable control technology (MACT) standards are based on emissions
levels that are already being achieved by the best-controlled and lower-emitting sources
in an industry.
•	Within eight years of setting MACT standards, the CAA directs EPA to assess the
remaining health risks from each source category to determine whether the MACT
standards protect public health with an ample margin of safety and protect against
adverse environmental effects. This second phase is a "risk-based" approach called
residual risk. Here, EPA must determine whether more health-protective standards are
necessary.
•	Also, every eight years after setting MACT standards, the CAA requires EPA to review
and revise the standards, if necessary, to account for improvements in air pollution
controls and/or prevention.
HOW TO COMMENT
•	EPA will accept comment on the proposal for 45 days after publication in the Federal
Register.
•	Comments, identified by Docket ID No. EPA-HQ-OAR-2017-0015, may be submitted by one
of the following methods:
o Go to https://www.regulations.gov and follow the online instructions for submitting
comments.
o Send comments by email to a-and-r-docket@epa.gov. Attention Docket ID No. EPA-
HQ-OAR-2017-0015.
o Fax your comments to: (202) 566-9744, Attention Docket ID No. EPA-HQ-OAR-2017-
0015.
o Mail your comments to: EPA Docket Center, Environmental Protection Agency, Mail
Code: 28221T, 1200 Pennsylvania Ave., NW, Washington, DC 20460, Attention
Docket ID No. EPA-HQ-OAR-2017-0015.
o Deliver comments in person to: EPA Docket Center 1301 Constitution Ave., NW,
Room 3334, Washington, DC. Note: In-person deliveries (including courier deliveries)
are only accepted during the Docket's normal hours of operation. Special
arrangements should be made for deliveries of boxed information.
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FOR MORE INFORMATION
•	Interested parties can download a copy of the proposed rule notice from EPA's website
at the following address: https://www.epa.gov/stationarv-sources-air-pollution/lime-
manufacturing-plants-national-emission-standards-hazardous-air.
•	Today's proposed action and other background information are also available either
electronically at https://www.regulations.gov. EPA's electronic public docket and
comment system, or in hardcopy at the EPA Docket Center's Public Reading Room.
o The Public Reading Room is located at EPA Headquarters Library, room number
3334 in the EPA WJC West Building, 1301 Constitution Ave., NW, Washington,
DC. Hours of operation are 8:30 a.m. to 4:30 p.m. local time, Monday through
Friday, excluding Federal holidays.
o Visitors are required to show photographic identification, pass through a metal
detector and sign the EPA visitor log. All visitor materials will be processed
through an X-ray machine as well. Visitors will be provided a badge that must be
visible at all times.
o Materials for this proposed action can be accessed using Docket ID No. EPA-HQ-
OAR-2017-0015.
•	For further technical information about the proposed rule, contact Jim Eddinger, EPA's
Office of Air Quality Planning and Standards, Sector Policies and Programs Division, at
(919) 541-5426 or eddinger.jim@epa.gov.
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