Mo. Code Regs. tit. 10 § 10-6.010
PURPOSE: This rule is a compilation of standards for ambient air quality throughout Missouri in order to protect the public health and welfare. The U.S. Environmental Protection Agency has set National Ambient Air Quality Standards (NAAQS) for six (6) criteria pollutants (carbon monoxide, lead, nitrogen dioxide, ozone, particle pollution, and sulfur dioxide). Primary NAAQS provide public health protection and secondary NAAQS provide public welfare protection. In addition, Missouri has set standards for hydrogen sulfide and sulfuric acid.
| Pollutant | Primary/Secondary Standard | Averaging Time | Level | Form | Reference Method | |
| Carbon monoxide | Primary | 8-hour | 9 parts per million | Not to be exceeded more than once per year | As specified in 10 CSR 10-6.040(4)(C) | |
| 1-hour | 35 parts per million | |||||
| Lead (2008) | Primary and secondary | Rolling 3-month average | 0.15 micrograms per cubic meter | Not to be exceeded (see 10 CSR 10-6.040(4)(O)) | As specified in 10 CSR 10-6.040(4)(G) | |
| Lead (1978)* | Primary | Calendar quarter mean | 1.5 micrograms per cubic meter | Not to be exceeded | As specified in 10 CSR 10-6.040(4)(G) | |
| Nitrogen dioxide | Primary | 1-hour | 100 parts per billion | 98th percentile, averaged over 3 years | As specified in 10 CSR 10-6.040(4)(F) | |
| Primary and secondary | Annual | 0.053 parts per million, equal to 53 parts per billion | Annual mean | |||
| Ozone (2008) | Primary and secondary | 8-hour | 0.075 parts per million | Annual fourth-highest daily maximum 8hour, averaged over 3 years (see 10 CSR 10-6.040(4)(N)) | As specified in 10 CSR 10-6.040(4)(D) | |
| Ozone (1997)** | Primary | 8-hour | 0.08 parts per million | Annual fourth-highest daily maximum 8hour, averaged over 3 years (see 10 CSR 10-6.040(4)(I)) | As specified in 10 CSR 10-6.040(4)(D) | |
| Particlepollution(2012) | Particulate matter 2.5 micron (PM2.5) | Primary | Annual | 12 micrograms per cubic meter | Annual mean, averaged over 3 years | As specified in 10 CSR 10-6.040(4)(L) |
| Secondary | Annual | 15 micrograms per cubic meter | Annual mean, averaged over 3 years | |||
| Primary and secondary | 24-hour | 35 micrograms per cubic meter | 98th percentile, averaged over 3 years (see 10 CSR 10-6.040(4)(M)) | |||
| Particulate matter 10 micron (PM10) | Primary and secondary | 24-hour | 150 micrograms per cubic meter | Not to be exceeded more than once per year on average over 3 years (see 10 CSR 10-6.040(4)(K)) | As specified in 10 CSR 10-6.040(4)(J) | |
| Particulate matter 2.5 micron (PM2.5) (1997)*** | Primary | Annual | 15 micrograms per cubic meter | Annual mean, averaged over 3 years | As specified in 10 CSR 10-6.040(4)(L) | |
| Sulfur dioxide (2010) | Primary | 1-hour | 75 parts per billion | 99th percentile of 1-hour daily maximum, averaged over 3 years | As specified in 10 CSR 10-6.040(A) | |
| Secondary | 3-hour | 0.5 parts per million, equal to 500 parts per billion | Not to be exceeded more than once per year | |||
| Sulfur dioxide (1971)**** | Primary | Annual | 0.03 parts per million | Annual mean | As specified in 10 CSR 10-6.040(A) | |
| Primary | 24-hour | 0.14 parts per million | Not to be exceeded more than once per year | |||
| Hydrogen sulfide | State only | 1/2-hour | 0.03 parts per million (42 micrograms per cubic meter) | Not to be exceeded over 2 times in any 5 consecutive days | As specified in 10 CSR 10-6.040(5) | |
| 1/2-hour | 0.05 parts per million (70 micrograms per cubic meter) | Not to be exceeded over 2 times per year | As specified in 10 CSR 10-6.040(5) | |||
| Sulfuric acid | State only | 1-hour | 30 micrograms per cubic meter | Not to be exceeded more than once in any 2 consecutive days | As specified in 10 CSR 10-6.040(6) | |
| 24-hour | 10 micrograms per cubic meter | Not to be exceeded more than once in any 90 consecutive days | As specified in 10 CSR 10-6.040(6) | |||
*The 1978 lead standard remains in effect until one (1) year after an area is designated for the 2008 standard, except that in areas designated nonattainment for the 1978 standard, the 1978 standard remains in effect until implementation plans to attain or maintain the 2008 standard are approved.
**The 1997 ozone standard and related implementation rules remain in place.
***The 1997 particulate matter 2. 5 micron ( PM 2. 5) standard remains in effect until one (1) year after an area is designated for the 2012 standard, except that in areas designated nonattainment for the 1997 standard, the 1997 standard remains in effect until implementation plans to attain or maintain the 2012 standard are approved.
****The 1971 annual and 24-hour sulfur dioxide standards remain in effect until one (1) year after an area is designated for the 2010 standard, except in areas designated nonattainment for the 1971 standards, where the 1971 standards remain in effect until implementation plans to atta in or maintain the 2010 standard are approved.
10 CSR 10-6.010