WAC 173-435-015. Significant harm levels

Significant harm levels are reached when any one of the following pollutant concentrations are measured: (1) Sulfur dioxide - 2,620 µg/m 3 (1.0 ppm), 24-hour average. (2) PM-10 - 600 micrograms/cubic meter, 24-hour average. (3) Carbon monoxide - 57.5 mg/m 3 (50 ppm), 8-hour average, 86.3 mg/m 3 (75 ppm) 4-hour average, 144 mg/m 3 (125 ppm) 1-hour average. (4) Ozone - 1,200 µg/m 3 (0.6 ppm) - 2-hour average. (5) Nitrogen dioxide - 3,750 µg/m 3 (2.0 ppm) 1-hour average, 938 µg/m 3 (0.5 ppm) 24-hour average.