Carbon Monoxide State Planning

The Clean Air Act regulates carbon monoxide as a criteria pollutant. The U.S. Environmental Protection Agency (EPA) sets National Ambient Air Quality Standards for carbon monoxide (CO). These standards include both primary standards to protect public health and secondary standards to protect the environment. EPA established the CO standards in 1971. Although the CO standards have gone through multiple periodic EPA reviews, the standards have not changed since that time. Therefore, no boundary designation processes for CO have occurred in many years. 

If you are looking for a document that is not available on our website, please submit a Open Records/ Sunshine Law Request.

1971 Standard

1-hour standard = 35 parts per million (ppm); 8-hour standard = 9 ppm

1971 Standard St. Louis Actions

MoDNR Submittal Date	MoDNR Action/Document	EPA Date	EPA Action/Document
April 3, 2014	Proposed Revision to the Limited Maintenance Plan for the St. Louis Nonclassifiable Maintenance Area for the 8-hour Carbon Monoxide National Ambient Air Quality Standard	Oct. 2, 2015	Approval and Promulgation of Implementation Plans; State of Missouri, Limited Maintenance Plan for the St. Louis Nonclassifiable Maintenance Area for the 8-Hour Carbon Monoxide National Ambient Air Quality Standard [80 FR  59611]