Sulfur oxide

Features of Sulfur oxide

Sulfur oxide, SO2, is a toxic and corrosive gas.

Physical and chemical properties

Physical state: Liquefied gas
Molecular weight: 64 g/mol
Smell: Pungent
Appearance/color: colorless


Sulfur oxide is used:

  • as fumigation agent in the treatment of materials such as wood;
  • in small quantities, in the treatment of foods such as wheat and wine;
  • in small quantities, as a preservative agent both in the vineyard and during the production of wine in order to protect the grapes and the wine from microbial attacks or further oxidation;
  • in calibration mixtures for environmental monitoring;
  • as a bleaching agent in the paper industry;
  • in the mining industry, due to the precipitation of sulfuric minerals.

Stability and reactivity

It reacts with the major part of metals in the presence of humidity releasing hydrogen, an extremely flammable gas.
It reacts with water to form corrosive acids.
It can reacts violently with alkali.
Combined with water, it causes rapid corrosion of some metals.