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Taking Toxics Out of the Air

Summaries of EPA's Final Air Toxics MACT Rules

Dry Cleaners
Final rule published September 22, 1993 Image of Dry Cleaning Facility

  • Dry cleaning facilities are the largest source of perchloroethylene (also called perc) emissions in the United States. Because dry cleaners are located in many communities across the country, perc emissions from dry cleaners are often released in close proximity to large numbers of people.
  • Perc can cause dizziness, nausea, and headaches and is suspected to cause cancer in humans.
  • EPA's rule requires all dry cleaners that use perc to implement pollution prevention measures. It also contains specific control requirements that vary depending on the type of machinery and the amount of perc a facility uses.
  • The rule affects approximately 30,000 dry cleaners and will reduce perc emissions at these facilities by about 7,300 tons per year.

Coke Oven Batteries at Steel Plants
Final rule published October 27, 1993

  • Coke oven batteries (a group of ovens connected by common walls) are used to convert coal into coke, which is then used in blast furnaces to convert iron ore to iron.
  • Coke oven emissions contain benzene (a known carcinogen) and other chemicals that can cause cancer of the respiratory tract, kidney, and prostate. Exposure to coke oven emissions can also cause conjunctivitis, severe dermatitis, and lesions of the respiratory and digestive systems.
  • EPA's rule provides guidelines for day-to-day operations and sets emissions limits for existing sources and even tighter limits for new sources. The rule was developed through a formal regultory negotiation process that involved extensive industry participation. It provides industry with a menu of compliance options-this flexibility should significantly reduce compliance costs.
  • The coke oven rule affects 29 existing facilities and reduces air toxics by approximately 1,500 tons per year.

Organic Chemical Production Plants
Final rule published April 22, 1994; additional final rule published May 12, 1998, for Tetrahydrobenzaldehyde ProductionImage of Chemical Plant

  • EPA's April 22, 1994 rule reduces emissions of 131 organic air toxics from chemical manufacturing processes in the Synthetic Organic Chemical Manufacturing Industry and from several other chemical production processes. The rule applies to production of about 385 chemicals.
  • The rule requires reductions in toxic organic air pollutants emitted from process vents, storage vessels, transfer racks, equipment leaks, and wastewater treatment systems.
  • Emissions averaging is allowed in the rule as a compliance option to give industry flexibility in meeting the emissions reduction limits.
  • The rule affects an estimated 310 facilities and will reduce air toxics emissions by 510,000 tons per year, a 90 percent reduction from the preregulated levels emitted by these facilities. The rule will also reduce VOCs by about 1 million tons per year, an 80 percent reduction from the preregulated levels emitted by these facilities, and equivalent to taking approximately 38 million cars off the road.
  • The May 12, 1998 rule added tetrahydrobenzaldehyde (THBA) to the list of Synthetic Organic Chemical Manufacturing Industry processes. THBA is used in the manufacture of paint additives.
  • Acrolein (a possible human carcinogen) and 1,3-butadiene (a probable human carcinogen) are released during the THBA production process.
  • Currently, only one facility in the nation manufactures THBA and would have to comply with this rule.

Industrial Process Cooling Towers
Final rule published September 8, 1994

  • Industrial process cooling towers are used to remove heat from industrial processes. In the past, chromium was added to cooling tower waters to prevent equipment corrosion and control algae growth.
  • Chromium (Chromium VI, the most toxic form, is known to cause lung cancer) is ultimately released from the cooling towers into the air. Most individual industrial process cooling towers do not qualify as major sources of air toxics; however, almost all cooling towers are part of large production facilities (e.g., petroleum refineries, chemical manufacturing plants, and primary metal producers) that do qualify.
  • EPA's rule prohibits the use of chromium-based water treatment chemicals and suggests that facilities substitute phosphate-based chemicals.
  • The rule affects an estimated 800 cooling towers at about 400 major sources nationwide and will reduce chromium emissions by 25 tons per year, a 100 percent reduction from the preregulated levels emitted by these facilities.

Halogenated Solvent Cleaning Machines
Final rule published December 2, 1994

  • Halogenated solvent cleaning machines (also known as degreasers) are used to clean oil and residues in the manufacturing and assembly of metal parts. Halogenated solvent cleaning is not a distinct industry, but it is an integral part of many industries, such as the aerospace and motor vehicle manufacturing industries. There are three basic types of solvent cleaning equipment:
    • Batch vapor cleaners, which heat the solvent to create a solvent vapor zone within which the parts are cleaned.
    • In-line cleaners, which are enclosed devices distinguished by a conveyor system used to supply a continuous stream of parts for cleaning. In-line cleaners include continuous web cleaning machines, which can clean parts such as film, coils, wire, and metal strips.
    • Batch cold cleaners, which use liquid solvent to remove soils from part surfaces.
  • The rule applies to cleaning machines that use methylene chloride, perchloroethylene, trichloroethylene, 1,1,1-trichloroethane, carbon tetrachloride, chloroform, or any combination of these solvents in a total concentration that is greater than 5 percent by weight.
  • EPA's rule combines equipment and work practice standards that emphasize pollution prevention. As an alternative to complying with the equipment standards option, facilities using batch vapor or in-line cleaning machines may demonstrate that each solvent cleaning machine emits less than an overall solvent emissions limit.
  • The rule affects an estimated 9,000 facilities that use solvent cleaning machines and will reduce air toxics emissions at these facilities by 85,300 tons per year and VOC emissions by 81,700 tons per year.

Commercial Sterilization and Fumigation Operations
Final rule published December 6, 1994

  • A number of industries (including medical equipment suppliers; pharmaceutical companies; cosmetics manufacturers; spice manufacturers; libraries, museums, and archives; and contact sterilizers) use ethylene oxide as a sterilant for heat- or moisture-sensitive materials or as a fumigant to control microorganisms or insects.
  • Ethylene oxide (a probable human carcinogen that also can cause adverse reproductive and developmental effects) is released during these operations.
  • EPA's rule sets ethylene oxide emissions limits for sterilization chamber vents, chamber exhaust vents, and aeration rooms.
  • The rule affects an estimated 114 sources and will reduce ethylene oxide emissions by about 1,000 tons per year, a 94 percent reduction from the preregulated levels emitted by these sources.

Gasoline Distribution FacilitiesImage of Gasoline Distribution Facility
Final rule published December 14, 1994

  • The gasoline distribution standard regulates bulk terminals and pipeline breakout stations, which transfer and store gasoline as it goes from petroleum refineries to service stations and gasoline bulk plants.
  • Approximately 10 toxic air pollutants, including benzene and toluene, are present in gasoline vapor. These pollutants are released from gasoline distribution facilities during tank truck and rail car loading operations, gasoline storage, and equipment leaks.
  • EPA's rule requires the use of pollution prevention methods (such as improving seals on storage tanks and inspecting equipment for leaks) and the use of controls (such as vapor processors to collect and treat gas vapors displaced during cargo tank loading operations).
  • The rule affects an estimated 240 gasoline bulk terminals and 20 pipeline breakout stations. It will reduce air toxics emissions from these facilties by 2,300 tons per year and VOC emissions by over 38,000 tons per year. In addition, the collection and/or prevention of gasoline evaporation under the final rule is expected to result in energy savings of an estimated 10 million gallons of gasoline per year.

Magnetic Tape Manufacturing
Final rule published December 15, 1994

  • Magnetic tape manufacturers make products such as audio and video cassettes and computer diskettes.
  • Toxic air pollutants are released when solvent mixtures are used during coating and equipment cleaning operations. In addition, particulate air toxics may be released when magnetic particles are transferred to the coating mixture.
  • EPA's rule requires 95 percent control for most types of emission points, including the coating operations. For some of these emission points, EPA has developed alternative emissions standards, such as one that allows facilities the flexibility to commit to more stringent control of their coating operations in lieu of controlling certain storage tanks.
  • The rule affects an estimated 14 of the 25 facilities that manufacture magnetic tape. It will reduce emissions of air toxics, most of which are VOCs, by 2,300 tons per year.

Chromium Electroplating and Anodizing OperationsImage of Chromium Electroplating Facility
Final rule published January 25, 1995

  • Chromium electroplating and anodizing operations coat metal parts and tools with a thin layer of chromium to protect them from corrosion and wear. Examples of electroplated parts include appliances, automotive parts, and large cylinders used in construction equipment and printing presses. Anodized parts include miscellaneous aircraft components such as wings and landing gears.
  • Hexavalent chromium (known to cause lung cancer) is released during the electroplating and anodizing processes.
  • EPA's rule sets specific emissions limits for new and existing chromium electroplating and anodizing operations that fall into specific size categories. The rule requires facilities to meet emissions limits through the use of pollution prevention practices and controls.
  • The rule affects an estimated 1,500 hard chromium electroplating facilities, 2,800 decorative chromium electroplating facilities, and 700 chromium anodizing facilities. It will reduce chromium emissions by 173 tons per year, a 99 percent reduction from the preregulated levels emitted by these facilities.

Basic Liquid Epoxy Resins and Non-Nylon Polyamide Resins Manufacture
Final rule published March 8, 1995

  • Basic liquid epoxy resins are used in the production of glues, adhesives, plastic parts, and surface coatings. Non-nylon polyamide or wet strength resins are used to improve the strength of paper.
  • Epichlorohydrin (strongly suspected of causing cancer and known to cause respiratory problems) is released during the resin manufacturing process.
  • EPA's rule is based on an epichlorohydrin emissions limit, which provides facilities with the flexibility to meet the regulation's requirements with a variety of compliance options. The rule also requires facilities to implement leak detection and repair programs.
  • The rule affects all three basic liquid epoxy resins manufacturing facilities and all nine non-nylon polyamide manufacturing facilities. It will reduce epichlorohydrin emissions by 110 tons per year.

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