OAR 340-206-0010: Introduction

OAR 340-206-0030, 340-206-0050 and 340-206-0060 are effective within priority I and II air quality control regions (AQCR) as defined in 40 CFR part 51, subpart H (1995), when the AQCR contains an AQMA as defined in OAR 340-204-0010, or a nonattainment area listed in 40 CFR part 81. All other rules in this division are equally applicable to all areas of the state. Notwithstanding any other regulation or standard, this division is designed to prevent the excessive accumulation of air contaminants during periods of atmospheric stagnation or at any other time, which if allowed to continue to accumulate unchecked could result in concentrations of these contaminants reaching levels which could cause significant harm to the health of persons. This division establishes criteria for identifying and declaring air pollution episodes at levels below the level of significant harm and are adopted pursuant to the requirements of the FCAA as amended and 40 CFR part 51.151. Levels of significant harm for various regulated pollutants listed in 40 CFR part 51.151 are: (1) For sulfur dioxide (SO2) — 1.0 ppm, 24-hour average. (2) For particulate matter: (a) PM10 — 600 micrograms per cubic meter, 24-hour average. (b) PM2.5 — 350.5 micrograms per cubic meter, 24-hour average. (3) For carbon monoxide (CO): (a) 50 ppm, 8-hour average. (b) 75 ppm, 4-hour average. (c) 125 ppm, 1-hour average. (4) For ozone (O3) — 0.6 ppm, 2-hour average. (5) For nitrogen dioxide (NO2): (a) 2.0 ppm, 1-hour average. (b) 0.5 ppm, 24-hour average. [NOTE: This rule is included in the State of Oregon Clean Air Act Implementation Plan that EQC adopted under OAR 340-200-0040.]