Air pollution control device (APCD) means any equipment that reduces the quantity of a pollutant that is emitted to the air.

Bag leak detection system means an instrument that is capable of monitoring PM loadings in the exhaust of a fabric filter in order to detect bag failures. A bag leak detection system includes, but is not limited to, an instrument that operates on triboelectric, light-scattering, light-transmittance, or other effects to monitor relative PM loadings.

Clay ceramics manufacturing facility means a plant site that manufactures pressed floor tile, pressed wall tile, other pressed tile, or sanitaryware (e.g., sinks and toilets). Clay ceramics manufacturing facilities typically process clay, shale, and various additives, form the processed materials into tile or sanitaryware shapes, and dry and fire the ceramic products. Glazes are applied to many tile and sanitaryware products. A plant site that manufactures refractory products, as defined in § 63.9824, or brick and structural clay products (BSCP), as defined in § 63.8515, is not a clay ceramics manufacturing facility.

Cooling stack means a stack (release point) installed on the cooling zone of a tunnel kiln to release air used to cool down the fired product from its maximum temperature to room temperature. A cooling stack does not release any air from the firing zone of the tunnel kiln.

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

Dioxin/furan means, for purposes of this subpart, the sum of the 2,3,7,8-TCDD toxic equivalents calculated using Equation 3 of this subpart.

Dry lime injection fabric filter (DIFF) means an APCD that includes continuous injection of hydrated lime or other sorbent into a duct or reaction chamber followed by a fabric filter.

Dry lime scrubber/fabric filter (DLS/FF) means an APCD that includes continuous injection of humidified hydrated lime or other sorbent into a reaction chamber followed by a fabric filter. These systems typically include recirculation of some of the sorbent.

Emission limitation means any emission limit or operating limit.

Emissions averaging sources means, for purposes of the emissions averaging provisions of § 63.8595(h), the collection of all existing ceramic tile roller kilns, sanitaryware tunnel kilns, ceramic tile glaze lines using glaze spraying, and sanitaryware glaze spray booths, within a kiln type and size category and within a subcategory.

Fabric filter means an APCD used to capture PM by filtering a gas stream through filter media; also known as a baghouse.

Fired product means clay ceramic or sanitaryware products that have gone through the firing process via kilns.

Glaze means a coating of colored, opaque, or transparent material applied to ceramic products before firing.

Glaze line means a production line for glazing ceramic products, which includes glaze spraying (typically comprised of one or more glaze spray booths) and other types of glazing operations (e.g., dipping, flooding, centrifugal disc glazing, curtain coating).

Glaze spray booth means a type of equipment used for spraying glaze on ceramic products.

Glaze spray operation means any type of glaze application that uses glaze spraying, including glaze lines and glaze spray booths.

Greenware means clay ceramic or sanitaryware products that have not gone through the firing process via kilns.

Initial startup means the time at which the kiln first reaches a level of production that is equal to 75 percent of the kiln design capacity or 12 months after the affected source begins firing clay ceramics, whichever is earlier.

Kiln design capacity means the maximum amount of clay ceramics, in Mg (tons), that a kiln is designed to produce in one year divided by the number of hours in a year (8,760 hours), taking into account the void space in the product, the push rate for the kiln, and the stacking pattern, if applicable. If a kiln is modified to increase the capacity, the design capacity is considered to be the capacity following modifications.

Minimum APCD inlet temperature means the minimum temperature that kiln exhaust can be vented to the APCD that ensures the long-term integrity of the APCD.

Particulate matter (PM) means, for purposes of this subpart, emissions of filterable PM that serve as a measure of total particulate emissions, as measured by Method 5 (40 CFR part 60, appendix A-3) or Method 29 (40 CFR part 60, appendix A-8), and as a surrogate for non-mercury metal HAP contained in the particulates including, but not limited to, antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, manganese, nickel, and selenium.

Period of natural gas curtailment or supply interruption means a period of time during which the supply of natural gas to an affected facility is halted for reasons beyond the control of the facility. An increase in the cost or unit price of natural gas does not constitute a period of natural gas curtailment or supply interruption.

Plant site means all contiguous or adjoining property that is under common control, including properties that are separated only by a road or other public right-of-way. Common control includes properties that are owned, leased, or operated by the same entity, parent entity, subsidiary, or any combination thereof.

Products of combustion (POC) stack means a stack (release point) installed on the front end of the firing zone of a tunnel kiln to release air used to heat the greenware from room temperature to its maximum temperature.

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

Roller kiln means a continuous kiln similar to a tunnel kiln except that the unfired ceramic product travels through the kiln in a single layer on rollers. In the clay ceramics source category, roller kilns are used at ceramic tile manufacturing plants.

Shuttle kiln means a batch firing kiln that is designed with a removable superstructure that is tilted or raised using hydraulic struts to allow entrance and egress. In the clay ceramics source category, shuttle kilns are used at sanitaryware manufacturing plants.

Spray dryer means a drying chamber used to form a free-flowing powder from a slurry of ceramic mix and water, to improve handling and compaction. In the clay ceramics source category, spray dryers are used at ceramic tile manufacturing plants.

Startup means the setting in operation of an affected source and starting the production process.

Startup production rate means the kiln, press dryer or spray dryer production rate required to bring the process unit to the proper operating temperature during startup.

Tunnel kiln means any continuous kiln that is not a roller kiln that is used to fire clay ceramics. In the clay ceramics source category, tunnel kilns are used at sanitaryware manufacturing plants.

Wet scrubber (WS) means an APCD that uses water, which may include caustic additives or other chemicals, as the sorbent. Wet scrubbers may use any of various design mechanisms to increase the contact between exhaust gases and the sorbent.

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

[80 FR 65543, Oct. 26, 2015, as amended at 84 FR 58609, Nov. 1, 2019]