Sulfur dioxide is one of a group of highly reactive gases known as oxides of sulfur. The largest sources of emissions are from fossil fuel combustion at power plants and other industrial facilities. Smaller sources include industrial processes such as extracting metal from ore, and the burning of high sulfur containing fuels by locomotives, large ships, and non-road equipment. Sulfur dioxide is linked with a number of adverse effects on the respiratory system. There are two standards in place for sulfur dioxide--a primary standard to protect human health, and a secondary 3-hour standard to protect the environment and property. Oklahoma is in attainment with both standards.



Pollutant Primary/
Secondary
Averaging
Time
Level Form
Sulfur Dioxide primary 1-hour 75 ppb 99th percentile of 1-hour daily maximum concentrations, averaged over 3 years
secondary 3-hour 0.5 ppm Not to be exceeded more than once per year

SO2 Monitoring Sites

The division monitors for sulfur dioxide at seven sites in the state. The monitors measure SO2 via approved fluorescent methods and report SO2 concentrations on an hourly basis. The values are then used to determine compliance with the standard. Data collected at the state's sulfur dioxide sites may be accessed here.

2013 SO2 Data

2013 SO2 Values2013 SO2 Values

*Final rule signed June 2, 2010. To attain this standard, the 3-year average of the 99th percentile of the daily maximum 1-hour average at each monitor within the area must not exceed 75 ppb.

**The Ponca City site moved locations in 2012. The data gathered at the new location cannot be compared to the standard until 3 years of complete data are collected. This chart reflects only that of 2012 and 2013.

**The Tulsa - Riverside site moved locations in 2013. The data gathered at the new location cannot be compared to the standard until 3 years of complete data are collected. This chart reflects only that of 2013.