Sodium metabisulfite

Agent Name
Sodium metabisulfite
CAS Number
Major Category
Other Classes
Sodium metabisulfite formula graphical representation
Campden Tablets; Disodium disulfite; Disodium metabisulfite; Disodium pyrosulfite; Disulfurous acid, disodium salt; Fertisilo; Natrii disulfis; Natrium metabisulfurosum; Natrium pyrosulfit; Natriumbisulfit; Natriummetabisulfit; Pyrosulfurous acid, disodium salt; Sodium bisulfite anhydrous; Sodium disulfite; Sodium metabisulfite; Sodium metabisulfite (Na2-S2O5); Sodium metabisulphite; Sodium pyrosulfite; Sodium pyrosulfite (Na2S2O5); [ChemIDplus]
White to yellowish crystals or powder with an odor of sulfur dioxide; [NIOSH]
Sodium and potassium metabisulfite are used as antioxidants in photographic film development. [Kanerva, p. 1637] Used as an antioxidant (food preservative, pharmaceutical aid, silage preservative; [HSDB] Used in the pickling stage of leather production; [PMID 21938525]
A case of occupational asthma, confirmed by specific inhalation challenge, was reported in which a worker sprinkled dry metabisulfite on potatoes. [Malo JL, Cartier A, Desjardins A. Occupational asthma caused by dry metabisulphite. Thorax 1995 May;50(5); 585-6.] Similar cases have been reported in the wine, laundry, and lobster fishing industries. [Madsen J, Sherson D, Kjoller H, Hansen I, Rasmussen K. Occupational asthma caused by sodium disulphite in Norwegian lobster fishing. Occup Environ Med 2004;61:873-874] Occupational skin sensitization has also been reported; [Sulfite contact allergy. Vena GA, Foti C, Angelini G. Contact Dermatitis 1994 Sep;31(3):172-5] In the presence of water and acid, metabisulfite can generate toxic amounts of SO2. [ATSDR Medical Management] A skin, eye, and respiratory tract irritant; May cause asthma; [ICSC] "It can be used as a reducing agent in photography and caused dermatitis in a photographic technician, probably acting as an aggravating irritative factor." [Kanerva, p. 1834] See "SULFITES." See "Potassium metabisulfite."
Biomedical References

Exposure Assessment

Skin Designation (ACGIH)
Insufficient data
5 mg/m3
Reference Link #2

Adverse Effects

Skin Sensitizer
ACGIH Carcinogen
Not Classifiable

Diseases, Processes, and Activities Linked to This Agent


Occupational diseases associated with exposure to this agent:


Industrial Processes with risk of exposure: