National Ambient Air Quality Standards (NAAQS)
The Air Toxics Program relies on delegated portions of the EPA program for permitting, compliance and enforcement, while emphasizing ambient monitoring to evaluate the air toxic concerns unique to Oklahoma. Rules for the Air Toxics Program can be found in Subchapter 42 and the list of pollutants and standards for the program can be found in Appendix O.
The pollutants in Appendix O were selected because of their relevance to Oklahoma. Should the levels in Appendix O be exceeded, an “area of concern” could be designated, allowing resources to be focused on finding local solutions to that area.
Toxic Program
| 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 | 9.0 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 | Annual | 10 ppb | Annual mean (3 yr avg) | ||
Where do we stand in relation to the NAAQS?
These charts keep track of the highest values for continuously-monitored criteria pollutants for the current year. The charts are updated each weekday (quarterly for annual PM2.5). Data presented in the charts is subject to further QA/QC and may differ from the formal attainment designations process, which usually occur after a NAAQS has changed. A list of Oklahoma’s attainment designations can be found in the Code of Federal Regulations in 40 CFR 81.337.
- 2025 8 Hour Carbon Monoxide Highs, 2024, 2023, 2022
- 2025 1 Hour Nitrogen Dioxide Highs, 2024, 2023, 2022
- 2025 8 Hour Ozone Highs, 2024, 2023, 2022
- 2025 24 Hour PM-2.5 Highs, 2024, 2023, 2022
- 2025 Annual PM-2.5 Highs, 2024 <Annual PM-2.5 charts began in 2024>
- 2025 1 Hour Sulfur Dioxide Highs, 2024, 2023, 2022
Air Data Report
DEQ also makes an annual Air Data Report after all data has gone through quality control, generally the summer following the year of sampling. Data for previous years are available upon request. Please contact the Monitoring section managers at 405-702-4100.
