Air Pollution Control Program

Area Source Standard Updates

What is an Area Source of Hazardous Air Pollutants and Why is it regulated?

Hazardous Air Pollutants, or HAPs, are toxic air pollutants that are known or suspected to cause cancer or other serious health effects (such as birth defects) or to cause adverse environmental effects. The Environmental Protection Agency, or EPA, has put together a list of 187 air pollutants that are considered HAPs.

Facilities that have the potential to generate at least 10 tons annually of a single hazardous air pollutant or at least 25 tons annually of a combination of all the hazardous air pollutants are called point (or major) sources.  An area source is a facility that has the potential to generate less than those levels of HAPs.

Point sources produce quite a bit of HAPs and are regulated by EPA. Area sources can contribute significantly to air pollution when several are located close to each other like in urban areas. The Clean Air Act, or CAA, required EPA to identify at least 30 HAPs that pose the greatest potential health threat in urban areas. EPA identified 33 urban HAPs (or air toxics). The CAA also required EPA to identify and regulate area source categories that represent 90 percent of the emissions of these urban HAPs.

Note icon. Note:
Due to the vast quantity of area sources regulated under the Generally Available Control Technology, or GACT, area source regulations and limited state resources, the department has not taken enforcement delegation of most the Hazardous Air Pollutant, or HAP, area source regulations with the exception of 40 CFR 63, Subpart M (commercial Dry-cleaning) and any others listed in Table 1 below.  However, the department is including the HAP area source regulations in our Title V permitting requirements for any HAP area sources which are otherwise Part 70 or intermediate sources.

EPA Region 7 contact responsible for the particular area source requirements

What are the State of Missouri Areas Source Requirements

Although the state has not taken enforcement delegation for most of the area source regulations, this does not mean that an area source is not subject to these requirements.  Area source requirements are federally enforceable and EPA can enforce these standards.  Table 1 below lists areas source requirements for which the Air Program is conducting compliance enforcement activities.  At this time the Air Pollution Control Program recommends facilities submit any notifications or other required reports for any emission units that are subject to the area source requirements to the Air Program in addition to the EPA.  Question regarding applicability of an area source standard to your facility or related compliance reporting issues should be directed to EPA Region 7 staff at the resource link below. 


EPA Compilation of Area Source Rules

EPA Area Source Standard

EPA Region 7 contacts

Table 1 On-line Compliance Resources for Missouri Area Source Requirements

40 CFR 63 Subpart and Source Category
Federal Register Notice
Compliance Date for
Existing Sources
Initial Notification Due
Title V Permit Requirement1
Notification of Compliance Due
Additional Information




Dry Cleaner Notification of Compliance Status, Form--MO 780-1987

Dry Cleaner Calendar

Korean Dry Cleaner Calendar

Amended EPA Regulations for Perchloroethylene Dry Cleaners

Korean Amended EPA Regulations for Perchloroethylene Dry Cleaners

Dry Cleaners and The Clean Air Act, Fact Sheet--PUB2201

1Affected facilities are exempt from Title V permit requirements provided they are not required to obtain a permit for another reason.

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