FACT SHEET
Final Amendments to Air Toxics Standards for Wet-Formed Fiberglass Mat Production
ACTION
•	On December 20, 2018 the U.S. Environmental Protection Agency (EPA) issued final
amendments to the 2002 National Emission Standards for Hazardous Air Pollutants
(NESHAP) for Wet-Formed Fiberglass Mat Production.
•	EPA is finalizing minor amendments to enhance the effectiveness of the rule by improving
compliance and implementation.
•	EPA issued the emission standards for Wet-Formed Fiberglass Mat Production on April 11,
2002. The rule applies to drying and curing ovens at facilities that produce mat made of
glass fibers bonded with a formaldehyde-based resin. The finished mat product is used for
applications such as backing material for asphalt shingles and roll roofing.
•	Following a residual risk and technology review (RTR) conducted under the Clean Air Act
(CAA), EPA proposed amendments to the Wet-Formed Fiberglass NESHAP on April 6, 2018.
In this final rule, EPA is:
o Revising requirements for periods of startup, shutdown and malfunction (SSM) to be
consistent with recent court decisions;
o Revising the definition of shutdown to be consistent with industry practice;
o Requiring electronic reporting of performance test results;
o Reducing the frequency of compliance reports to a semiannual basis in all instances;
and
o Reducing the parameter monitoring and recording requirements during periods
when the binder formulation being applied to glass fibers to form mat does not
contain any hazardous air pollutants (HAP).
•	Residual Risk Review: In accordance with the CAA, EPA is required to assess the risk
remaining after the promulgation of the final air toxics standards. This is known as a
residual risk review. Based on the completed risk assessment, EPA has determined that risks
from the Wet-Formed Fiberglass Mat Production source category are acceptable and
provide an ample margin of safety to protect public health.
•	Technology Review: The CAA also 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 wet-formed fiberglass mat
production facilities did not identify any 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.
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•	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 8 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 8 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.
•	The Wet-Formed Fiberglass Mat Production NESHAP is one of 96 air toxic standards
covering 174 industry sectors which have been promulgated by EPA.
FOR MORE INFORMATION
•	Interested parties can download a copy of the final rule from EPA's website at the following
address: https://www.epa.gov/stationarv-sources-air-pollution/wet-formed-fiberglass-mat-
production-national-emission-standards.
•	Today's final rule and other background information are also available either electronically
at http://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 Avenue, NW, Washington, DC.
Hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Standard 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 final rule can be accessed using Docket ID No. EPA-HQ-OAR-2004-
0309.
•	For further technical information about the final rule, contact Susan Fairchild, EPA's Office
of Air Quality Planning and Standards, at (919) 541-5167 or Fairchild.susan@epa.gov.
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