Oregon Administrative Rules › Chapter 340 - DEPARTMENT OF ENVIRONMENTAL QUALITY › Division 246 - OREGON STATE AIR TOXICS PROGRAM › Section 340-246-0030 - Definitions

Current through Register Vol. 63, No. 7, July 1, 2024
The definitions in OAR 340-200-0020, 340-218-0030,
				340-244-0030, OAR 340-247-0020  and this rule apply to this division. If the
				same term is defined in this division and elsewhere, the definition in this
				division applies.
(1) "Ambient
			 benchmark concentration" means the concentration of a toxic air contaminant in
			 outdoor air that would result in an excess lifetime cancer risk level of one in
			 a million (1 x 10-6) or a non-cancer hazard quotient of one and is numerically
			 equivalent to the "Toxicity Reference Value" as defined under OAR 340
			 247-0020.
(2) "Geographic area"
			 means an area identified by DEQ where toxic air contaminant concentrations are
			 estimated or measured at levels that exceed ambient benchmark
			 concentrations.
(3) "Hazard
			 quotient" means the ratio of the potential exposure to a single toxic air
			 contaminant to the reference concentration for that pollutant. If the hazard
			 quotient is calculated to be less than or equal to 1, then no adverse health
			 effects are expected as a result of exposure. If the hazard quotient is greater
			 than 1, then adverse health effects are possible.
(4) "High priority geographic area" means an
			 area identified by DEQ where toxic air contaminant concentrations are estimated
			 or measured at levels that exceed ambient benchmark concentrations and pose
			 excess cancer risk above ten in a million, or non-cancer risk above a hazard
			 quotient of one with the potential for serious adverse health
			 effects.
(5) "Public receptor"
			 means any outdoor area where members of the public have unrestricted access,
			 including but not limited to residences, institutions (e.g. schools,
			 hospitals), industrial, commercial, or office buildings, parks, recreational
			 areas, public lands, streets or sidewalks.
(6) "Reference concentration" means an
			 estimate of a continuous exposure or a daily exposure to the human population
			 (including sensitive populations) that is likely to be without an appreciable
			 risk of adverse non-cancer effects during a lifetime. The reference
			 concentration can be derived from various types of human or animal data, with
			 uncertainty factors generally applied to reflect limitations of the data
			 used.
(7) "Sensitive human
			 populations" means humans with increased susceptibility to the adverse effects
			 of toxic air contaminants, including humans in prenatal or postnatal periods of
			 development.
(8) "Source" means:
(a) An activity conducted by a person at a
			 point, area, on-road mobile, or off-road mobile operation that emits toxic air
			 contaminants; or
(b) Any building,
			 structure, facility, installation or combination thereof that emits or is
			 capable of emitting air contaminants to the atmosphere, is located on one or
			 more contiguous or adjacent properties and is owned or operated by the same
			 person or by persons under common control. The term includes all pollutant
			 emitting activities that belong to a single major industrial group (i.e., that
			 have the same two-digit code) as described in the
Standard Industrial
			 Classification Manual
, (U.S. Office of Management and Budget, 1987) or
			 that support the major industrial group.