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Wet-Formed Fiberglass Mat Production: National Emission Standards for Hazardous Air Pollutants (NESHAP)

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Rule Summary

Section 112 of the Clean Air Act (CAA) establishes a two-stage regulatory process to address emissions of hazardous air pollutants (HAP) from stationary sources. In the first stage, we must promulgate technology-based standards or natioanl emission standards for hazardous air pollutants (NESHAP) for major sources of HAP. “Major sources” are those that emit, or have the potential to emit, any single HAP at a rate of 10 tons per year (tpy) or more, or 25 tpy or more of any combination of HAP.

In the second stage of the regulatory process, the CAA requires the Environmental Protection Agency (EPA) to evaluate the risk to public health remaining after application of the NESHAP and revise the standards, if necessary, to provide an ample margin of safety to protect public health or to prevent (taking into consideration costs, energy, safety, and other relevant factors) an adverse environmental effect. In this second phase we must also review the technology-based standards and revise them “as necessary (taking into account developments in practices, processes, and control technologies)”.

Wet-formed fiberglass mat production is on the list of categories of major sources of HAP published under section 112(c) of the Clean Air Act (CAA). This source category includes new and existing sources at wet-formed fiberglass mat production facilities. The primary organic HAP emitted by these facilities are formaldehyde, methanol, and vinyl acetate.

Wet-formed fiberglass mat is produced at both stand-alone facilities and those collocated with asphalt roofing and processing facilities. In wet-formed fiberglass mat production, glass fibers are bonded with an organic resin. The mat is formed as the resin is dried and cured in heated ovens.

Rule History

2/28/2019 - Final amendments

04/06/2018 - Proposed amendments

03/19/2018 - Proposed amendments FACT Sheet

04/11/2002 – Final Rule and notice of revisions to list of categories of major and area sources and to the promulgation schedule for standards

05/26/2000 – Proposed Rule

Related Rules

Asphalt Processing and Asphalt Roofing Manufacturing: National Emission Standards for Hazardous Air Pollutants (NESHAP) for Area Sources

Asphalt Processing and Asphalt Roofing Manufacturing: National Emission Standards for Hazardous Air Pollutants (NESHAP) for Major Sources

Asphalt Processing and Asphalt Roofing Manufacture: New Source Performance Standards (NSPS)

Control of Volatile Organic Compounds From Use of Cutback Asphalt

Hot Mix Asphalt Facilities: New Source Performance Standards (NSPS)

Additional Resources

Fact Sheets for Wet-formed Fiberglass Mat Production Risk and Technology Review Actions


Applicability Determination Index (ADI).  The ADI is maintained by EPA's Office of Enforcement and Compliance Assurance (OECA) and provides a data base of memoranda dealing with applicability issues.  The database is searchable by Subpart.