Terms used in this subpart are defined in the Clean Air Act, in 40 CFR 63.2, the General Provisions of this part, and in this section as follows:

Adhesive applicator means the equipment that uses open pan-type application (e.g., a roller partially submerged in an open pan of adhesive) to apply adhesive to roofing shingles for producing laminated or dimensional roofing shingles.

Asphalt flux means the organic residual material from distillation of crude oil that is generally used in asphalt roofing manufacturing and paving and non-paving asphalt products.

Asphalt loading rack means the equipment at an asphalt processing facility used to transfer oxidized asphalt from a storage tank into a tank truck, rail car, or barge.

Asphalt processing facility means any facility engaged in the preparation of asphalt flux at stand-alone asphalt processing facilities, petroleum refineries, and asphalt roofing facilities. Asphalt preparation, called “blowing,” is the oxidation of asphalt flux, achieved by bubbling air through the heated asphalt, to raise the softening point and to reduce penetration of the oxidized asphalt. An asphalt processing facility includes one or more asphalt flux blowing stills, asphalt flux storage tanks storing asphalt flux intended for processing in the blowing stills, oxidized asphalt storage tanks, and oxidized asphalt loading racks.

Asphalt roofing manufacturing facility means a facility consisting of one or more asphalt roofing manufacturing lines.

Asphalt roofing manufacturing line means the collection of equipment used to manufacture asphalt roofing products through a series of sequential process steps. The equipment that comprises an asphalt roofing manufacturing line varies depending on the type of substrate used (i.e., organic or inorganic) and the final product manufactured (e.g., roll roofing, laminated shingles). For example, an asphalt roofing manufacturing line that uses fiberglass mat as a substrate typically would not include a saturator/wet looper (or the saturator/wet looper could be bypassed if the line manufacturers multiple types of products). An asphalt roofing manufacturing line can include a saturator (including wet looper), coater, coating mixers, sealant applicators, adhesive applicators, and asphalt storage and process tanks. The number of asphalt roofing manufacturing lines at a particular facility is determined by the number of saturators (or coaters) operated in parallel. For example, an asphalt roofing manufacturing facility with two saturators (or coaters) operating in parallel would be considered to have two separate roofing manufacturing lines.

Asphalt storage tank means any tank used to store asphalt flux, oxidized asphalt, and modified asphalt, at asphalt roofing manufacturing facilities, petroleum refineries, and asphalt processing facilities. Storage tanks containing cutback asphalts (asphalts diluted with solvents to reduce viscosity for low temperature applications) and emulsified asphalts (asphalts dispersed in water with an emulsifying agent) are not subject to this subpart.

Blowing still means the equipment in which air is blown through asphalt flux to change the softening point and penetration rate of the asphalt flux, creating oxidized asphalt.

Boiler means any enclosed combustion device that extracts useful energy in the form of steam and is not an incinerator.

Coater means the equipment used to apply amended (filled or modified) asphalt to the top and bottom of the substrate (typically fiberglass mat) used to manufacture shingles and rolled roofing products.

Coating mixer means the equipment used to mix coating asphalt and a mineral stabilizer, prior to applying the stabilized coating asphalt to the substrate.

Combustion device means an individual unit of equipment such as a flare, incinerator, process heater, or boiler used for the combustion of organic hazardous air pollutant vapors.

Deviation means any instance in which an affected source subject to this subpart, or an owner or operator of such a source:

(1) Fails to meet any requirement or obligation established by this subpart including, but not limited to, any emission limitation (including any operating limit), or work practice standard;

(2) Fails to meet any term or condition that is adopted to implement an applicable requirement in this subpart, and that is included in the operating permit for any affected source required to obtain such a permit; or

(3) Before September 9, 2020, fails to meet any emission limitation (including any operating limit) or work practice standard in this subpart during startup, shutdown, or malfunction, regardless of whether or not such failure is permitted by this subpart. On and after September 9, 2020, this paragraph (3) no longer applies.

Emission limitation means any emission limit, opacity limit, operating limit, or visible emission limit.

Group 1 asphalt loading rack means an asphalt loading rack that loads asphalt with a maximum temperature of 260 °C (500 °F) or greater and has a maximum true vapor pressure of 10.4 kiloPascals (kPa) (1.5 pounds per square inch absolute (psia)) or greater.

Group 2 asphalt loading rack means an asphalt loading rack that is not a Group 1 asphalt loading rack.

Group 1 asphalt storage tank means an asphalt storage tank that meets both of the following criteria:

(1) Has a capacity of 177 cubic meters (47,000 gallons) of asphalt or greater; and

(2) Stores asphalt at a maximum temperature of 260 °C (500 °F) or greater and has a maximum true vapor pressure of 10.4 kPa (1.5 psia) or greater.

Group 2 asphalt storage tank means any asphalt storage tank with a capacity of 1.93 megagrams (Mg) of asphalt or greater that is not a Group 1 asphalt storage tank.

Incinerator means an enclosed combustion device that is used for destroying organic compounds. Auxiliary fuel may be used to heat waste gas to combustion temperatures. Any energy recovery section present is not physically formed into one manufactured or assembled unit with the combustion section; rather, the energy recovery section is a separate section following the combustion section and the two are joined by ducts or connections carrying flue gas.

Maximum true vapor pressure means the equilibrium partial pressure exerted by the stored asphalt at its maximum storage temperature.

Modified asphalt means asphalt that has been mixed with polymer modifiers.

Oxidized asphalt means asphalt that has been prepared by passing air through liquid asphalt flux in a blowing still.

Process heater means an enclosed combustion device that primarily transfers heat liberated by burning fuel directly to process streams or to heat transfer liquids other than water.

Research and development equipment means any equipment whose primary purpose is to conduct research and development to develop new processes and products, where such equipment is operated under the close supervision of technically trained personnel and is not engaged in the manufacture of products for commercial sale in commerce, except in a de minimis manner.

Responsible official means responsible official as defined in 40 CFR 70.2.

Saturator means the equipment in which substrate (predominantly organic felt) is filled with asphalt. Saturators are predominantly used for the manufacture of saturated felt products. The term saturator includes the saturator and wet looper.

Sealant applicator means the equipment that uses open pan-type application (e.g., a roller partially submerged in an open pan of sealant) to apply a sealant strip to a roofing product. The sealant strip is used to seal overlapping pieces of roofing product after they have been applied.

Work practice standard means any design, equipment, work practice, or operational standard, or combination thereof, that is promulgated pursuant to section 112(h) of the Clean Air Act.

[68 FR 24577, May 7, 2003, as amended at 70 FR 28364, May 17, 2005; 85 FR 14552, Mar. 12, 2020]