Agent Name
Sulfur dioxide
Major Category
Toxic Gases & Vapors
Synonyms
Sulfurous acid anhydride; Sulfurous oxide; Sulfur oxide; [NIOSH]
Description
Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14 degrees F. Shipped as a liquefied compressed gas.] [NIOSH]
Sources/Uses
Formed as a byproduct of burning sulfur-containing materials; used for bleaching, disinfecting, and fumigating; [ACGIH] Used to preserve fruits and other foods; manufacture molasses, wine, and beer; bleach textile fibers; tan leather; pulp wood; manufacture lithium batteries and glass; treat water; and refine oil and metal; [HSDB]
Comments
Listed as one of "major irritant airborne toxicants"; [LaDou, p. 523] Possible frostbite from contact with liquid; [NIOSH] In the presence of water and acid, metabisulfite, a preservative, can generate toxic amounts of SO2. [ATSDR Med. Manage. Guidelines] The following chemicals can release SO2 when spilled in water: Sulfur chlorides; Sodium, Potassium, Calcium & Zinc hydrosulfite; and Thionyl chloride. [ERG 2016] See the Process, "Toxic Gas from Spilling Chemical in Water." Sulfur dioxide is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans. [LaDou, p. 383]
Skin Designation (ACGIH)
Insufficient data
Excerpts from Documentation for IDLHs
The maximum concentration for exposures of 0.5 to 1 hour is considered to be 50 to 100 ppm [Henderson and Haggard 1943]. It has been reported that 400 to 500 ppm is considered dangerous for even short periods of exposure [Henderson and Haggard 1943].
Odor Threshold Low
0.33 ppm
Odor Threshold High
5 ppm
Lethal Concentration
LC50 (rat) = 2,520 ppm/1H
Explanatory Notes
Detection odor threshold from AIHA (mean = 2.7); Boiling point = -10 deg C; [ICSC]
Half Life
No reports found; [TDR, p. 1098]
IARC Carcinogen
Not classifiable
ACGIH Carcinogen
Not Classifiable
Diseases
Occupational diseases associated with exposure to this agent:
Processes
Industrial Processes with risk of exposure:
Activities
Activities with risk of exposure: