Contaminants | Averaging time (hours) | Stage 1 | Stage 2 | Stage 3 |
Nitrogen dioxide | 1 | 0.6 ppm | 1.2 ppm | 1.6 ppm. |
24 | 0.15 ppm | 0.3 ppm | 0.4 ppm. | |
Particulate matter | 24 | 3.0 COH | 5.0 COH | 7.0 COH. |
24 | 375 ugm-3 | 625 ugm-3 | 875 ugm-3. | |
Sulfur dioxide and particulate matter combined | 24 | 0.21 | 0.81 | 1.21. |
24 | 65,0002 | 261,0002 | 393,0002. |
1 Product of sulfur dioxide (ppm) and particulate matter (COH).
2 Product of sulfur dioxide (ugm-3 ) and particulate matter (ugm-3 ).
Environmental Protection Agency, Air and Hazardous Materials Division (A-4), Attn: Air Programs Branch, 215 Fremont Street, San Francisco, Calif. 94105.
Pollutant | Averaging time (hours) | Stage 1 | Stage 2 | Stage 3 |
Carbon monoxide | 4 | 1 25 | 1 45 | 1 60 |
8 | 1 15 | 1 30 | 1 40 |
1 Parts per million by volume.
Pollutant | Averaging time (hours) | Stage 1 | Stage 2 | Stage 3 |
Particulate matter | 24 | 1 375 | 1 625 | 1 875 |
1 Micrograms per cubic meter.
Regional Administrator, Attn: Air and Hazardous Materials Division, Air Technical Branch, Technical Analysis Section (A-4-3), Environmental Protection Agency, 215 Fremont Street, San Francisco CA 94105.
Pollutant | Averaging time (hours) | [MICRO]g/m3 | ||
Stage 1 | Stage 2 | Stage 3 | ||
Particulate matter | 24 | 375 | 625 | 875 |
Pollutant | Averaging time (hours) | Stage 1 (ppm) | Stage 2 (ppm) | Stage 3 (ppm) |
Carbon monoxide | 4 | 25 | 45 | 60 |
8 | 15 | 30 | 40 |
Regional Administrator, ATTN: Air and Hazardous Materials Division, Air Technical Branch, Technical Analysis Section (A-4-3), Environmental Protection Agency, 215 Fremont Street, San Francisco, CA 94105.
Pollutant | Averaging time (hours) | [MICRO]g/m3 | ||
Stage 1 | Stage 2 | Stage 3 | ||
Particulate matter | 24 | 375 | 625 | 875 |
Photochemical oxidants | 1 | 1 0.5 |
1 Parts per million.
40 C.F.R. §52.274
For FEDERAL REGISTER citations affecting § 52.274 , see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.govinfo.gov.