National Ambient Air Quality Standards (NAAQS) - Attainment Status
The Clean Air Act, which was last amended in 1990, requires the United States environmental protection agency (USEPA) to set National Ambient Air Quality Standards (40 CFR part 50) for pollutants considered harmful to public health and the environment. The Clean Air Act identifies two types of national ambient air quality standards. Primary standards provide public health protection, including protecting the health of "sensitive" populations such as asthmatics, children, and the elderly. Secondary standards provide public welfare protection, including protection against decreased visibility and damage to animals, crops, vegetation, and buildings.
The USEPA has set National Ambient Air Quality Standards for six principal pollutants, which are called "criteria" air pollutants. Periodically, the standards are reviewed and may be revised. The current standards are listed below. Units of measure for the standards are parts per million (ppm) by volume, parts per billion (ppb) by volume, and micrograms per cubic meter of air (g/m3).
Fact Sheets
- NAAQS and Nonattainment - What Businesses Need to Know
- NAAQS and Nonattainment - What Citizens Need to Know
| Pollutant | Primary/Secondary Standards |
Averaging Time | Level | Form | Ohio Attainment Status | |
| Carbon monoxide | primary | Eight-hour | 9 ppm | Not to be exceeded more than once per year |
Full Attainment | |
| One-hour | 35 ppm | Full Attainment | ||||
| Lead(Pb) | primary and secondary |
Rolling three-month Average |
0.15 g/m3 | Not to be exceeded | Full Attainment Stark county partial nonattainment |
|
| Nitrogen dioxide | primary and secondary |
One-year | 53 ppb | Annual Mean | Full Attainment | |
| primary | One-hour | 100 ppb | 98th percentile of 1-hour daily maximum concentrations, averaged over 3 years |
Full Attainment | ||
| Particulate matter | PM10 | primary and secondary |
24-hour | 150 g/m3 | Not to be exceeded more than once per year on average over 3 years |
Full Attainment |
| PM2.5 | primary | One-year | 12.0 g/m3 (2012 Std.) | annual mean, averaged over 3 years | Full Attainment | |
| secondary | One-year | 15.0 g/m3 (1997 Std.) |
annual mean, averaged over 3 years | Full Attainment | ||
| primary and secondary |
24-hour | 35 g/m3 (2006 Std.) |
98th percentile, averaged over 3 years | Full Attainment | ||
| Ozone |
primary and secondary |
Eight-hour | 0.070 ppm (2015 std) |
Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years |
Map | |
| primary and secondary |
Eight-hour | 0.075 ppm (2008 std) |
Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years |
Full Attainment | ||
| primary and secondary |
Eight-hour | 0.08 ppm (1997 std) |
Annual fourth-highest daily maximum 8-hour concentration, averaged over 3 years |
Full Attainment | ||
| Sulfur dioxide | primary | One-hour | 75 ppb | 99th percentile of 1-hour daily maximum concentrations, averaged over 3 years |
Map | |
| secondary | Three-hour | 0.5 ppm | Not to be exceeded more than once per year |
Full Attainment | ||
