National Ambient Air Quality Standards
The National Ambient Air Quality Standards (NAAQS) are standards established by the United StatesEnvironmental Protection Agencythat apply for outdoor airthroughout the country. Primary standards are designed to protect human health, including sensitive populations such as children, the elderly, and individuals suffering from respiratory disease. Secondary standards are designed to protect public welfare (e.g. buildingfacades, visibility, crops, and domestic animals).
NAAQS requires the EPA to set standards on six criteria pollutants:
- Ozone(O3)
- Particulate Matter
- PM10 implementation (2.5 micrometresto 10 micrometres in size)
- PM2.5 implementation (2.5 micrometres in size or less)
- Carbon monoxide(CO)
- Sulfur dioxide(SO2)
- Nitrogen oxides(NOx)
- Lead(Pb)
Standards
| Pollutant | Type | Standard | Averaging Timea | Regulatory Citation
|
| SO2
| Primary
| 0.14 ppm(365 ?g/m3)
| 24-hour
| 40 CFR50.4(b)
|
| SO2
| Primary
| 0.030 ppm (80 ?g/m3)
| annual
| 40 CFR 50.4(a)
|
| SO2
| Secondary
| 0.5 ppm (1,300 ?g/m3)
| 3-hour
| 40 CFR 50.5(a)
|
| PM10
| Primary and Secondary
| 150 ?g/m3
| 24-hour
| 40 CFR 50.6(a)
|
| PM10
| Primary and Secondary
| 50 ?g/m3
| annual
| 40 CFR 50.6(b)
|
| PM2.5
| Primary and Secondary
| 65 ?g/m3
| 24-hour
| 40 CFR 50.7(a)
|
| PM2.5
| Primary and Secondary
| 15 ?g/m3
| annual
| 40 CFR 50.7(a)
|
| CO
| Primary
| 35 ppm (40 mg/m3)
| 1-hour
| 40 CFR 50.8(a)(2)
|
| CO
| Primary
| 9 ppm (10 mg/m3)
| 8-hour
| 40 CFR 50.8(a)(1)
|
| O3
| Primary and Secondary
| 0.12 ppm (235 ?g/m3)
| 1-hourb
| 40 CFR 50.9(a)
|
| O3
| Primary and Secondary
| 0.08 ppm (235 ?g/m3)
| 8-hour
| 40 CFR 50.10(a)
|
| NOx
| Primary and Secondary
| 0.053 ppm (100 ?g/m3)
| annual
| 40 CFR 50.11(a) and (b)
|
| Pb
| Primary and Secondary
| 1.5 ?g/m3
| quarterly
| 40 CFR 50.12
|
Note a: Each standard has its own criteria for how may times it may be exceeded, in some cases using a three year average.
Note b: As of June 15, 2005, the 1-hour ozone standard no longer applies to areas designated with respect to the 8-hour ozone standard (which includes most of the United States, except for portions of 10 states).
Source: USEPA
See also
- Asthma
- Clean Air Act (USA) (1990)
- Pollution
- TSCA(Toxic Substances Control Act)
- Air Quality Index
External links
- EPA summary of the National Ambient Air Quality Standards
- EPA summary for Air & Radiation
Categories: Toxicology| Pollution
This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/National+Ambient+Air+Quality+Standards Wikipedia article National Ambient Air Quality Standards.
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