Sulfur dioxide - SO2

This page presents information on sulfur dioxide - or sulfurous anhydride - (SO2), appropriate detection means - SO2 detector - and suitable respiratory protective equipment (gas mask or powered air purifying respirator with E gas filter).

Sulfur dioxide (SO2) properties

Sulfur dioxide (SO2) – also called sulfurous anhydride – is present in many fields of activity such as the pulp and paper industry, power plants, the cooling industry and fossil energy combustion (coal and fuel). It is also used for wine growing application (sulfiting). Even if it can be naturally found near volcanoes, this gas is essentially anthropogenic (man-made).

CAS TWA (8 hours) STEL (15 minutes) LEL IP Density / Air Filter / SCBA
7446-09-5 0.5 ppm 1 ppm - 12.3 eV 2.26 E

Sulfur dioxide effects on health

Sulfur dioxide (SO2) is a colorless gas with a pungent fragrance that may cause breathing system and eyes irritation starting at 1 ppm! Even if it is corrosive and harmful, this gas is above all toxic. It has been classified as R23 (toxic by inhalation) and R34 (causes burns). Lastly, sulfur dioxide is very reactive with many solvents (alcohol, toluene), and particularly with water to produce sulfuric acid (H2SO4). SO2 is also responsible for acid rain.


Sulfur dioxide exposure dangers, effects on health: why use an SO2 detector

Sulfur dioxide health effects (SO2)

SO2 detector - Sulfur dioxide

SO2 respiratory protection (Sulfure dioxide)