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

Hazardous air pollutants (HAPs) are known or suspected to cause adverse environmental effects and/or serious health effects. The U.S. Environmental Protection Agency (EPA) has identified 187 air pollutants, for example, benzene, which is found in gasoline. EPA places standards, or requirements on categories of stationary sources that emit (or have the potential to emit) one or more hazardous air pollutants called national emission standards for hazardous air pollutants (NESHAP)standards. EPA lists these standards and which agency enforces the standards in tables published in the Federal Register. Click here to access the tables.

Major source of hazardous air pollutants: The term "major source"  refers to any stationary source or group of stationary sources that emits or has the potential  to emit 10 tons per year of any of the 187 named pollutants, or 25 tons per year of a mixture of pollutants.

Area source of hazardous air pollutants: The term "area source" refers to facilities that release smaller quantities of toxic air pollutants. Although emission from one area source may be relatively small, multiple area sources concern environmental specialists, especially when they are in densely populated areas.

To reduce the hazardous area pollutants released by area sources, EPA places standards, or requirements, on area sources to minimize emissions. These requirements call for specific management practices and generally available control technologies (GACT). These technologies consist of methods, practices, and techniques applicable to area sources. When EPA developed these technologies, staff members considered the economic impact as well as the technical abilities of employees to operate and maintain systems for emission control.

What are Missouri's Area Source Requirements?

  • The following table gives area source requirements for which the Missouri Department of Natural Resources is conducting compliance-enforcement activities. Direct questions regarding standards, compliance, and reports about area sources to the agency listed as “Regulating Agency” in the table, below. The department's Air Pollution Control Program recommends that facilities submit notifications and other required reports about area sources to the air program and EPA Region 7 contacts. If you have questions regarding any of the area source regulations or need help navigating the requirements, contact the Air Pollution Control Program at 573-751-4817.

Dry Cleaners

Table 1 Online Compliance Resources for Missouri Area Source Requirements

Search Search Search Search Search
Regulating Agency Description 40 CFR 63 Subpart Title V Permit Keyword Rule and Implementation Information Regulation Helpful Links
EPA Wool Fiberglass Manufacturing at Area Sources (2N) - NN Major Permit Assumed Fiberglass, Wool Link Link  
EPA Gasoline Distribution (6B) - BBBBBB Exempt Gasoline Link Link Link
EPA Gasoline Distribution (6B) - BBBBBB Exempt Gasoline Link Link Link
EPA Flexible Polyurethane Foam Production & Fabrication Industry (6O) - OOOOOO Exempt Polyurethane foam Link Link  
EPA Wood Preserving Industry (6Q) - QQQQQQ Exempt Wood Preserving Link Link  
EPA Nine Metal Fabrication and Finishing Source Categories (6X) - XXXXXX Exempt Metal Fab and Finish Link Link Link
MoDNR Coke Oven Batteries (Reg refers to Sources, not area or major. ) (1L) - L Major Permit assumed Coke Ovens Link Link  
MoDNR Dry Cleaning Facilities (Major and area sources) (1M) - M Exempt Dry cleaning Link Link Link
MoDNR Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks (Major and area sources) (1N) - N Exempt Chromium Link Link  
MoDNR Ethylene Oxide Emissions Standards for Sterilization Facilities (Major and area sources) (1O) - O Exempt Ethylene Oxide Link Link  
MoDNR Halogenated Solvent Cleaning (Major and area sources) (1T) - T Exempt Solvent Cleaning Link Link  
MoDNR Secondary Lead Smelting (Major and area sources) (1X) - X Major Required Lead Link Link  
MoDNR Marine Tank Vessel Loading Operations
(Major and new area sources)
(1Y) - Y Required Vessel Link Link  
MoDNR Oil and Natural Gas Production Facilities (Major and area sources) (2H) - HH Exempt Oil and Natural Gas Link Link  
MoDNR Printing and Publishing Industry ( Some Major sources that can prove actuals below HAP limits) (2K) - KK Major Permit assumed Printing Link Link Link
MoDNR Hazardous Waste Incineration Regulations (Major and area sources) (3E) - EEE Major Required Hazardous Waste Link Link  
MoDNR Portland Cement Regulations (Major and area sources) (3L) - LLL Major Required Cement Link Link  
MoDNR Secondary Aluminum Production (Major and area sources) (3R) - RRR Exempt Aluminum Link Link  
MoDNR Primary Lead Smelting (3T) - TTT Major Permit Assumed Lead Link Link Link
MoDNR Publicly Owned Treatment Works Regulations (Major and area sources) (3V) - VVV Exempt Sewer company Link Link  
MoDNR Municipal Solid Waste Landfills (Major and area sources) (4A) - AAAA Required Landfill Link Link Link
EPA- Area
MoDNR - Ma
Reciprocating Internal Combustion Engines (Major and area sources) (4Z) - ZZZZ Exempt Internal Combustion Engines Link Link Link
MoDNR Mercury Cell Chlor-Alkali Plants (Major and area sources) (5I) - IIIII Major Required Mercury Cell Chlor-Alkali Link Link  
EPA Hospital Ethylene Oxide Sterilizers (5W) - WWWWW Exempt Hospital Link Link  
EPA Electric Arc Furnaces Steelmaking Facilities (5Y) - YYYYY Major Required Steel Link Link Link
EPA Iron and Steel Foundries (5Z) - ZZZZZ Exempt Foundry Link Link  
EPA Gasoline Dispensing Facilities (6C) - CCCCCC Exempt Gasoline Link Link Link
EPA Polyvinyl Chloride and Copolymers Production (6D) - DDDDDD Exempt Polyvinyl Chloride Link Link  
EPA Primary Copper Smelting (6E) - EEEEEE Major Required Copper Link    
EPA Secondary Copper Smelting (6F) - FFFFFF Major Required Copper Link    
EPA Primary Nonferrous Metals Area Sources—Zinc, Cadmium, and Beryllium (6G) - GGGGGG Major Required Zinc, Cadmium, and Beryllium Link    
EPA Paint Stripping and Miscellaneous Surface Coating Operations (6H) - HHHHHH Exempt Paint Link Link Link
EPA Industrial, Commercial, and Institutional Boilers (6J) - JJJJJJ Exempt Boilers Link Link Link
EPA Acrylic and Modacrylic Fibers Production (6L) - LLLLLL Exempt Acrylic Fibers Link    
EPA Carbon Black Production (6M) MMMMMM Major Permit required Carbon Black Link    
EPA Chemical Manufacturing Area Sources:  Chromium Compounds (6N) - NNNNNN Major Permit required Chromium Mfg Link    
EPA Lead Acid Batteries Industry (6P) - PPPPPP Exempt Lead Link Link  
EPA Clay Ceramics Manufacturing Industry (6R) - RRRRRR Exempt Ceramics Link Link  
EPA Glass Manufacturing Industry (6S) - SSSSSS Major Permit required Glass Link Link  
EPA Secondary Nonferrous Metals Processing (6T) - TTTTTT Exempt Nonferrous metals Link Link  
EPA Chemical Manufacturing Area Sources (6V) VVVVVV Maybe Chemical Link Link Link
EPA Plating and Polishing Operations (6W) - WWWWWW Exempt Plating and Polishing Link Link Link
EPA Ferroalloys Production Facilities (6Y) - YYYYYY Exempt Ferroalloy Link Link  
EPA Aluminum, Copper and Other Nonferrous Foundries (6Z) - ZZZZZZ Exempt Aluminum and copper Link Link  
EPA Asphalt Processing and Asphalt Roofing Manufacturing (7A) - AAAAAAA Exempt Asphalt Link Link  
EPA Chemical Preparations Industry (7B) - BBBBBBB Exempt Chemical Link Link  
EPA Paints and Allied Products Manufacturing (7C) - CCCCCCC Exempt Paint Link    
EPA Prepared Feeds Manufacturing (7D) - DDDDDDD Exempt Animal feed Link Link Link
EPA Gold Mine Ore Processing and Production (7E) - EEEEEEE Major Permit required Gold Mine Link Link