Sulfur dioxide (SO₂) is a colourless liquefied toxic gas with a sharp, suffocating pungent smell. It has a melting point of ‑72 ℃ and boiling point of ‑10 ℃. As a highly toxic and corrosive substance, it is categorized as hazard class 2.3 toxic gas for transportation. Strict safety handling, proper ventilation and protective equipment are mandatory during storage, transport and field usage. Widely applied in chemical synthesis, food‑processing preservation, water treatment and industrial bleaching sectors.
