Sulfur Dioxide

Sulfur dioxide is formed during the combustion of fossil fuels that contain sulfur, such as oil, natural gas, and coal.  It is regulated by the EPA as a criteria air pollutant, and along with NOx, is a principal contributor to acid rain. 

Sulfur dioxide reacts with other chemicals to form particulate pollution, which can damage lungs and cause respiratory illness, heart conditions, and premature death.  Sulfur dioxide has a pungent odor and irritates membranes in the nose and in the respiratory system.

Flares and machinery that runs on diesel and natural gas emit sulfur dioxide at oil and gas operations.  Sour gas processing plants also emit sulfur dioxide.