Sulfur dioxide (sulfur dioxide) is the most common, simplest, and irritating sulfur oxide with the chemical formula SO2. Sulfur dioxide is a colorless and transparent gas with a pungent odor. Soluble in water, ethanol and ether, liquid sulfur dioxide is relatively stable, inactive, non-combustible, and does not form an explosive mixture with air. Sulfur dioxide has bleaching properties. Sulfur dioxide is commonly used in industry to bleach pulp, wool, silk, straw hats, etc. Sulfur dioxide can also inhibit the growth of mold and bacteria.