Related topics

Sulfur Dioxide SO2 Gas Detection & Gas Detectors

Sulfur Dioxide (SO2) is a toxic gas that is released in various industrial processes and naturally in volcanic eruptions. Coal and petroleum often contain sulfur compounds and their combustion generates Sulfur Dioxide unless the sulfur compounds are removed before burning the fuel.

Chlorine Gas DetectorTypical applications where dangerous levels of Sulfur Dioxide (SO2) might occur and benefit from a Sulfur Dioxide gas detector are:

    • Petroleum refining
    • Paper manufacturing
    • Winemaking
    • Sulfuric acid production
    • Food processing (preservative)
    • Sulfide ore smelting
    • Coal or fuel oil powered plants

Sulfur Dioxide is intensely irritating to the eyes and respiratory tract. Workplace exposure to SO2 can cause both chronic and acute effects. The chronic effects of exposure include permanent pulmonary impairment, which is caused by repeated episodes of bronchoconstriction. High exposures can result in various respiratory diseases.

Exposure Limits (Source: OSHA)

Following are Sulfur Dioxide exposure limits that industries should be aware of when researching Sulfur Dioxide gas detectors and gas detection systems.

Agency Exposure Limits
OSHA PEL (General Industry) 5 ppm TWA
OSHA PEL (Construction Industry) 5 ppm TWA
OSHA PEL (Maritime) 5 ppm TWA
NIOSH REL 2 ppm TWA; 5 ppm STEL
NIOSH IDLH 100 ppm


  • TWA = Time Weighted Average exposure concentration for a normal 8-hour workday and 40-hour workweek
  • STEL = Short Term Exposure Limit (Usually a 15-minute time-weighted average exposure that should not be exceeded at any time during a workday
  • NIOSH (National Institute for Occupational Safety and Health)
    • REL = Recommended Exposure Limit
    • IDLH = Immediately Dangerous to Life or Health Concentration
  • OSHA (Occupational Safety and Health Administration)
    • PEL = Permissible Exposure Limit
  • ACGIH (American Conference of Government Industrial Hygienists)
    • TLV = Threshold Limit Value

Sierra Monitor has several different Sulfur Dioxide gas detectors dependent upon the application.