FACT SHEET

Proposed Amendments to Air Toxics Standards
for Refractory Products Manufacturing

ACTION

•	On January 4, 2021, the U.S. Environmental Protection Agency (EPA) proposed amendments
to the 2003 National Emission Standards for Hazardous Air Pollutants (NESHAP) for
Refractory Products Manufacturing.

•	Refractory products are heat-resistant materials such as bricks and shapes, monolithic
products, kiln furniture and crucibles. These products are designed for use in industrial
settings with very high temperatures.

•	Processes in this source category include the crushing, grinding and screening of raw
materials; mixing the processed raw materials with binders and other additives; forming the
refractory mix into shapes; and drying and firing the shapes.

•	The Refractory Products Manufacturing source category includes four subcategories: clay
refractories, non-clay refractories, chromium refractories, and pitch-impregnated
refractories.

•	Following a residual risk and technology review (RTR) conducted under the Clean Air

Act (CAA), EPA determined that risks from the source category are acceptable. Based on the
technology review, EPA is proposing improvements to the work practice standards that
apply during scheduled maintenance of control devices for emissions of organic air toxics
from continuous kilns.

•	In addition, the EPA is addressing unregulated pollutants as follows:

o Clay refractory product manufacturers. Emissions limits for mercury and particulate

matter (as a surrogate for non-mercury metal air toxics),
o Nonclay refractory product manufacturers. A work practice standard to use natural gas
as fuel to reduce metal air toxics emissions.

•	EPA is proposing other minor amendments to the rule, including:

o revised regulatory provisions related to emissions during periods of startup, shutdown

and malfunction; and
o provisions for electronic reporting of certain notifications and reports.

RESIDUAL RISK ASSESSMENT

•	The CAA requires EPA to assess the risk remaining after application of the final air toxics
emissions standard. This is known as a residual risk assessment.

•	Clay facilities in this source category mainly emit acid gases that result from firing of clay
that contains these chemicals. Non-clay facilities mainly emit organic air toxics from organic
binders that are used to hold the raw materials together.

•	The inhalation cancer maximum individual risk (MIR) based on actual emissions is less than
1-in-l million for the Refractory Products Manufacturing source category.

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•	An MIR of 1-in-l million implies that up to one person out of one million equally exposed
people could contract cancer if exposed continuously (24 hours per day) to the specific
concentration over 70 years (an assumed lifetime). This would be in addition to cancer
cases that would normally occur in one million unexposed people.

•	Additional health risk screenings and ecological risk screenings do not indicate levels of
concern.

•	EPA determined the remaining risk after application of the technology-based standards is
acceptable, and the standards provide and ample margin of safety to protect public health
and the environment.

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.

•	Based on the results of the technology review, EPA is proposing amendments to the
NESHAP, including new emissions limits and work practice standards.

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 the 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
prevention practices and technologies.

HOW TO COMMENT

•	EPA will accept comments for 45 days after the proposal is published in the Federal
Register.

•	Comments, identified by Docket ID No. EPA-HQ-OAR-2020-0148 may be submitted by one
of the following methods:

o Go to https://www.reeulations.gov/ and follow the on-line instructions for submitting
comments.

o Send comments by email to a-and-r-docket@epa.gov. Attention Docket ID No. EPA-
HQ-OAR-2020-0148.

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•	Out of an abundance of caution for members of the public and our staff, the EPA Docket
Center and Reading Room are closed to the public, with limited exceptions, to reduce the
risk of transmitting COVID-19. Our Docket Center staff will continue to provide remote
customer service via email, phone and webform.

o We encourage the public to submit comments via https://www.regulations.gov/ or
email, as there may be a delay in processing mail and faxes. Hand deliveries and
couriers may be received by scheduled appointment only,
o For further information on EPA Docket Center services and their current status,
please visit us online at https://www.epa.gov/dockets.

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/refractory-
products-manufacturing-national-emissions-standards.

•	Today's action and other background information are also available electronically at
https://www.regulations.gov/. EPA's electronic public docket and comment system.

•	For further technical information about the rule, contact Paula Hirtz, EPA's Office of Air
Quality Planning and Standards, at (919) 541-2618 or hirtz.paula@epa.gov.

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