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Taking Toxics Out of the Air

Summaries of EPA's Final Air Toxics MACT Rules

Primary Aluminum Reduction Industry
Final rule published October 7, 1997

    Fluoride Emissions Bar Graph: Pre-rule 7,400 tons compared to Post-rule 3,700 tons
  • Primary aluminum reduction plants produce molten aluminum metal (virgin aluminum) from alumina ore. Typically, primary aluminum plants are components of larger facilities that prepare a variety of finished products. These larger facilities also typically include secondary aluminum plant operations, which use aluminum metal to make products such as cans, aircraft and automotive products, and construction materials. Standards for secondary aluminum production are covered under a separate rule.
  • Air toxics released during the production of molten aluminum metal include hydrogen fluoride (which can cause serious respiratory damage) and polycyclic organic matter (which is strongly suspected of causing cancer and other serious health effects).
  • Particulate Matter Bar Graph: Pre-rule 32,000 tons compared to Post-rule 16,000 tons
  • Developed in partnership with state regulators, industry stakeholders, and tribal governments, EPA's final rule contains an emissions averaging provision that allows facilities to overcontrol some emissions points while undercontrolling others, thus achieving the required reductions in the most cost-effective manner possible. As a further cost-saving incentive, facilities that consistently perform below the levels set in the standard will be allowed to reduce the frequency of sampling or emissions testing.
  • To achieve the required reductions, the final rule relies on a combination of pollution prevention measures, including work practices, equipment modifications, operating practices, housekeeping measures, and in-process recycling.
  • Polycyclic Organic Matter Emissions Bar Graph: Pre-rule 4,000 tons compared to Post-rule 2,000 tons
  • The rule affects 24 facilities nationwide. It will reduce fluoride emissions by about 3,700 tons per year, polycyclic organic matter emissions by about 2,000 tons per year, and particulate matter emissions by 16,000 tons per year. These emission levels represent a reduction of approximately 50 percent from preregulated levels.

Pulp and Paper Mills
Two final rules published April 15, 1998

Air Toxics Emissions Bar Graph: Pre-rule 258,000 tons compared to Post-rule 103,000 tons
  • Wood and non-wood fiber sources such as cotton, linen, and straw are turned into pulp either though cooking via chemicals (known as digestion), mechanical grinding, or a combination of both. Following digestion or grinding, the resulting fibrous mass is washed, screened, and (depending on the final product) sometimes bleached.
  • A number of toxic air pollutants (including chloroform, chlorine, formaldehyde, methanol, acetaldehyde, methyl ethyl ketone, and metals) are released during cooking, washing, bleaching, and chemical recovery processes at these facilities.
  • EPA's air toxics rules are part of an integrated, multimedia regulation designed to control pollutant releases to the water and air. The integrated rules allow the pulp and paper industry to consider all regulatory requirements at one time in order to select the most effective pollution prevention and control technologies.
  • EPA has issued two final air toxics standards for the pulp and paper industry that cover emissions from pulping and bleaching processes at mills that chemically pulp wood, and certain bleaching processes at non-wood, mechanical, and secondary fiber mills. These standards do not require controls on paper machines at any mills and on pulping operations at non-wood, mechanical, and secondary fiber mills.
  • The final rules will affect approximately 155 mills and will reduce air toxics emissions by 155,000 tons per year, a 60 percent reduction from current levels. The rules will also reduce VOC emissions by 450,000 tons per year and total sulfur emissions by 86,000 tons per year.

Pharmaceutical Production
Final rule published September 21, 1998 Air Toxics Emissions Bar Graph: Pre-rule 36,900 tons compared to Post-rule 12,900 tons

  • Pharmaceutical production includes operations such as chemical synthesis, formulation, and natural extraction, used to produce drugs and medications.
  • The production of pharmaceuticals results in the release of a number of air toxics, including methylene chloride, methanol, toluene, and hydrogen chloride.
  • This rule, developed in partnership with representatives from industry and states, provides a variety of compliance options. Facility operators may choose to meet either emission limits or control efficiency requirements for storage tanks and process vents. Operators may elect to comply with the pollution prevention alternative in lieu of the standards for process vents, storage tanks, equipment leaks, and wastewater where the operator has reduced the hazardous air pollutant usage for a product process.
  • Approximately 100 pharmaceutical production facilities nationwide will be affected by this rule. When fully implemented, the rule will reduce air toxics emissions by 24,000 tons annually, a 65 percent reduction from current levels.

Flexible Polyurethane Foam Production
Final rule published October 7, 1998Air Toxics Emissions from Slabstock and Molded Foam Facilities Bar Graph: Pre-rule 19,247 tons compared to Post-rule 5,447 tons

  • This rulemaking affects only flexible polyurethane foam that is manufactured at slabstock, molded, and rebond polyurethane production facilities. These segments of the industry manufacture cushions, bedding materials, and other speciality products.
  • The production of flexible polyurethane foam results in the release of air toxics, primarily methylene chloride, which is a probable human carcinogen that can adversely affect the central nervous system.
  • This rule is based on pollution prevention techniques and flexible requirements. A variety of compliance options are available to facility operators. As a result of the rule, the use of methylene chloride at molded foam production facilities will be eliminated.
  • Approximately 78 slabstock, 98 molded, and 21 rebond foam facilities nationwide will be affected by this rule. When fully implemented, the rule will reduce air toxics emissions by 11,500 tons annually at slabstock foam facilities (a 68 percent reduction from current levels), and by 2,300 tons annually at molded foam facilities (a 98 percent reduction from current levels). All rebond foam facilities are believed to be in compliance with this rule; therefore, no further reductions are expected.

Ferroalloys Production: Ferromanganese and Silicomanganese
Final rule published May 20, 1999

  • A ferroalloy is a mixture of iron and one or more other elements, such as chromium, manganese, or silicon. Ferroalloys are primarily used in the manufacturing of steel and cast iron products with enhanced or special properties.
  • The production of ferroalloys results in the release of a number of metallic air toxics, including manganese. The variety and quantity of pollutants emitted are related to the amount of metals present in the raw materials. Manganese can adversely affect human health. For example, chronic exposure to high levels of manganese primarily affects the central nervous system.
  • This final rule sets limits for particulate emissions from one ferromanganese and silicomanganese production plant. Particulate matter is used as a surrogate for the air toxic manganese emitted from this facility. Particulate control devices are known to remove metallic pollutants with essentially the same efficiency as they remove particulates.
  • The facility already has control equipment in place to comply with EPA's rule. This equipment reduces air toxics emissions by 99 percent from uncontrolled levels. The rule is not expected to bring about additional reductions, but will ensure continued use and good operation of existing control equipment.

Polyether Polyols ProductionAir Toxics Emissions Bar Graph: Pre-rule 4,000 tons compared to Post-rule 2,000 tons
Final rule published June 1, 1999

  • Polyether polyols are used as an ingredient in lubricants, adhesives, cosmetics, soaps, and polymers for urethane production.
  • A number of air toxics are released during the production of polyether polyols. These include ethylene oxide, propylene oxide, toluene, and hexane, all of which can cause cancer or other adverse health effects.
  • EPA's rule establishes emission limits and control efficiency requirements for storage tanks, process vents, equipment leaks, and wastewater treatment systems. For several of the emission units, industry can choose from a number of compliance approaches.
  • Of the 80 facilities affected by this rule, roughly half have already installed emission control devices. When fully implemented, the rule will reduce air toxic emissions by approximately 2,000 tons annually, a reduction of 50 percent from current levels.

Mineral Wool ProductionAir Toxics Emissions Bar Graph: Pre-rule 342 tons compared to Post-rule 82 tons
Final rule published June 1, 1999

  • Mineral wool is made by melting natural rock, blast furnace slag, and other materials in a furnace known as a cupola, and then forming the molten material into a fiber. Depending on the final product, an oil or a phenol/formaldehyde-based binder is applied. Fiber to which oil has been applied is then sized and bagged or baled. Fiber to which a phenol/formaldehyde-based binder has been applied is thermoset in a curing oven and cooled.
  • Mineral wool is used as an industrial and structural insulator. It is also added to other products to provide structural strength, sound absorbency, or fire protection.
  • Production of mineral wool can lead to releases of a variety of air toxics, including arsenic (a known human carcinogen) and beryllium, cadmium, lead, and formaldehyde (probable human carcinogens).
  • EPA's rule requires facilities to reduce air toxics emissions from existing and new cupolas, using particulate matter as a surrogate for the metallic toxics (e.g., arsenic, beryllium, cadmium, lead). Additionally, facilities must reduce emissions of carbonyl sulfide from new cupolas, using carbon monoxide as a surrogate for carbonyl sulfide. The rule also requires reduction of phenol and formaldehyde emissions from curing ovens.
  • The rule allows flexibility by offering a choice of compliance options (emission limits or percent reduction standards). The rule's use of surrogate pollutants will also help reduce monitoring and emission testing costs.
  • The rule will affect 15 mineral wool production facilities nationwide. When fully implemented, it will reduce air toxics and particulate matter emissions from cupolas, and formaldehyde and phenol emissions from curing ovens, by 260 tons annually, a reduction of 76 percent.

Primary Lead Smelters
Final rule published June 4, 1999

  • Primary lead smelters process lead ore to produce lead metal. The majority of this lead is then used to manufacture lead-acid batteries.
  • A variety of air toxics are released during primary lead smelting operations. These include lead, arsenic, antimony, and cadmium.
  • EPA's rule will control emissions by setting plant-wide lead emission limits. These limits are based on pre-existing limits established by the states in which affected facilities are located. The rule gives owners and operators the flexibility to determine how and to what extent each source is controlled to achieve the required emission limits. The rule also details several work practice requirements for the control of fugitive dust, and the operation and maintenance of air pollution control equipment.
  • Three manufacturing facilities will be affected by this rule. The emissions limits are based on pre-existing state emissions limits. As such, no direct emissions reduction can be estimated based solely on the emissions limits. EPA expects that as a result of following the fugitive dust work practice and monitoring requirements, facilities will achieve air toxics emission reductions by improving equipment performance and reducing the potential for fugitive dust emissions.

Phosphoric Acid Manufacturing and Phosphate Fertilizer Production
Two final rules published June 10, 1999Air Toxics Emissions Bar Graph: Pre-rule 605 tons compared to Post-rule 260 tons

  • Phosphoric acid is used in the production of phosphate-based fertilizers, which are used for farming and other agricultural purposes.
  • A variety of air toxics can be released to the atmosphere during the production of phosphoric acid and phosphate fertilizers.
  • EPA's rules require facilities to reduce emissions of air toxics from the following emissions points: wet process phosphoric acid plants, superphosphoric acid plants, purified phosphoric acid plants, phosphate rock dryers, phosphate rock calciners, mono- and di-ammonium phosphate fertilizer plants, and granular triple superphosphate fertilizer plants and storage buildings. The rules are structured to limit emissions across process lines that include several different emissions points. The rules establish a single limit for each process line, allowing facilities the flexibility to operate and control each line in the most efficient manner while still achieving specific emission reductions.
  • The rules affect an estimated 21 facilities. The rules will reduce emissions of toxic air pollutants (primarily hydrogen fluoride) by approximately 345 tons per year, a 57 percent reduction from current levels. They will also reduce emissions of total fluorides by 1,035 tons per year, and will yield small reductions in emissions of heavy metals. Total fluorides are known to damage vegetation and have other adverse effects on the environment.

Wool Fiberglass Manufacturing
Final rule published June 14, 1999

  • Wool fiberglass is a constituent of a variety of insulation products, including building and pipe insulation. It is produced from sand, feldspar, sodium sulfate, anhydrous borax, boric acid, and other materials.
  • A variety of air toxics are released to the atmosphere during the production of wool fiberglass. These include arsenic (a known human carcinogen), and lead and formaldehyde (probable human carcinogens).
  • EPA's rule applies to the following types of facilities: glass manufacturing furnaces, rotary spin manufacturing lines producing building insulation, flame attenuation (FA) manufacturing lines producing pipe products, and FA manufacturing lines producing heavy-density insulation products. The rule also contains new emission test methods for measuring formaldehyde.
  • The rule provides owners and operators flexibility in meeting the emission limits by encouraging process modifications and pollution prevention techniques, instead of more costly add-on controls.
  • Of the 27 facilities currently manufacturing wool fiberglass nationwide, 21 will be affected by this rule. The rule will reduce emissions of formaldehyde by 580 tons annually, a reduction of 30 percent. The rule will also reduce particulate matter emissions by 840 tons per year and emissions of toxic metals (including arsenic, chromium, and lead) by 20 pounds per year-a reduction of 30 percent from current levels.
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