Terms used in this subpart are defined in the Clean Air Act, §63.2, and in this section as follows:

Air scavenging system means an air collection and control system that collects and removes vapors from a thermal treatment process vessel and vents the emissions to a vapor recovery tank that collects condensate from the vapors.

Chromated copper arsenate (CCA) means a chemical wood preservative consisting of mixtures of water-soluble chemicals containing metal oxides of chromium, copper, and arsenic. CCA is used in pressure treated wood to protect wood from rotting due to insects and microbial agents.

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 emissions limitation or management practice;

(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) Fails to meet any emissions limitation or management practice in this subpart during startup, shutdown, or malfunction, regardless of whether or not such failure is permitted by this subpart.

Pressure treatment process means a wood treatment process involving an enclosed vessel, usually a retort, and the application of pneumatic or hydrostatic pressure to expedite the movement of preservative liquid into the wood.

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

Retort means an airtight pressure vessel, typically a long horizontal cylinder, used for the pressure impregnation of wood products with a liquid wood preservative.

Thermal treatment process means a non-pressurized wood treatment process where the wood is exposed to a heated preservative.

Wood preserving means the pressure or thermal impregnation of chemicals into wood to provide effective long-term resistance to attack by fungi, bacteria, insects, and marine borers.