Okla. Admin. Code § 252:100-9-2
The following words and terms, when used in this subchapter, shall have the following meaning, unless the context clearly indicates otherwise:
"Bypass" means intentionally avoiding the use of air pollution control equipment.
"Excess emissions" means the emission of regulated air pollutants or opacity in excess of an applicable limitation or requirement as specified in the applicable rule(s), enforceable permit, administrative order or judicial order.
"Excess emission episode" means a continuous period of excess emissions occurring from one emission unit.
"Excess emission event" means the period of time during which excess emissions occurred, either continuously or intermittently, as a result of the same primary cause. An excess emission event may include one or more excess emission episodes.
"Primary cause" means the fundamental aspect of the cause that can logically be identified. In the event of a series of causes, one leading to another, the fundamental cause is the primary cause.
"Working day" means 8:00 a.m. to 4:30 p.m. each day except Saturday, Sunday, or a legal holiday for state employees as proclaimed by the Governor.
Okla. Admin. Code § 252:100-9-2