National Ambient Air Quality Standards (NAAQS)
The National Ambient Air Quality Standards (NAAQS) define the maximum permissible concentrations for certain pollutants, known as criteria pollutants. Click on the pollutant name for the relevant DEQ factsheet.
| Pollutant |
Standard | Averaging Time | Level | Form | |
| Carbon Monoxide (CO) |
Primary | 8-hour | 9 ppm | Not to be exceeded more than once per year | |
| 1-hour | 35 ppm | ||||
| Lead (Pb) | Primary and Secondary | Rolling 3 month average | 0.15 μg/m³ | Not to be exceeded | |
| Nitrogen Dioxide (NO2) |
Primary | 1-hour | 100 ppb | 98th percentile (3 yr avg) | |
| Primary and Secondary | Annual | 53 ppb | Annual mean | ||
| Ozone (O3) | Primary and Secondary | 8-hour | 0.070 ppm | Annual 4th-highest daily max 8-hr concentration (3 yr avg) | |
| Particulate Matter |
PM10 | Primary and Secondary | 24-hour | 150 μg/m³ | Not to be exceeded more than once per year (3 yr avg) |
| PM2.5 |
Primary | Annual | 12 μg/m³ | Annual mean (3 yr avg) | |
| Secondary | Annual | 15 μg/m³ | Annual mean (3 yr avg) | ||
| Primary & Secondary | 24-hour | 35 μg/m³ | 98th percentile (3 yr avg) | ||
| Sulfur Dioxide (SO2) |
Primary | 1-hour | 75 ppb | 99th percentile of 1-hour daily max concentrations (3 yr avg) | |
| Secondary | 3-hour | 0.5 ppm | Not to be exceeded more than once per year | ||
Where do we stand in relation to the NAAQS for 2019?
These charts keep track of the highest values for continuously-monitored criteria pollutants in 2019. The charts are updated each weekday. For data from previous years, visit our Past Air Data page.