Sulfur Dioxide Gas Detectors (SO2 Detectors)

SO2Sulfur dioxide (SO2) is a colorless, extremely toxic gas with a strong odor. Common applications of sulfur dioxide include sulfuric acid production, pulp and paper mills, chemical processing, food and beverage, coking operations and petroleum refineries. Since coal and petroleum often contain sulfur compounds, their combustion will generate SO2 unless the sulfur compounds are removed before the fuel is burned. To keep workers safe from sulfur dioxide exposure, as well as other hazardous gases that may be present, Industrial Scientific offers a wide range of portable gas detection instruments including the Tango® TX1 and GasBadge® Pro single-gas detectors, the Ventis® Pro, Ventis® MX4, MX6 iBrid® multi-gas detectors, as well as the Radius® BZ1 Area Monitor.

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Sulfur Dioxide - SO2


Flammable -

Will not explode


Health -

Extremely toxic 


Oxidizing -

Oxidizing agent


Sulfurous acid anhydride, sulfurous oxide, and sulfur oxide

Exposure limits:


PEL\TWA: 5 ppm



STEL: 0.25 ppm/ 15 min.



IDLH: 100 ppm / 30 min.


Pulp and paper mills and coal-fired generating stations

Sulfur dioxide is a colorless gas with a characteristic, irritating, pungent odor. Sulfur dioxide is released when compounds containing sulfur, such as fossil fuels like coal are burned.

Sulfur dioxide is a highly toxic gas which poisons its victims via inhalation through the lungs. SO2 combines with water to form sulfuric acid (H2SO4). It is for this reason that sulfur dioxide can burn the respiratory tract upon inhalation. High doses of sulfur dioxide can cause death quite rapidly.

Effects of Various SO2 Levels

Sulfur Oxide
Level in PPM

Resulting Conditions on Humans


Sulfur Dioxide initially detected by taste.


Permissible Exposure Level (OSHA).


Odor becomes easily detected.


Irritation of the nose and throat.


Irritation of the eyes.


Maximum exposure for a 30 minute period.


Dangerous concentration can cause edema of the lungs and glottis and death from prolonged exposure.

Source: Dangerous Properties of Industrial Materials (Sixth Edition) by N. Irving Sax



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