Sodium Thiosulfate
ALTERNATIVE NAMES
Disodium Thiosulfate, Sodium Hyposulfite
TECHNICAL SPECIFICATIONS
CAS
7772-98-7
EC
231-867-5
Food Code
E539
Sodium thiosulfate, also known as hypo, is a white crystalline solid with formula Na2S2O3 and molecular weight 158.11 g/mol (anhydrous). Density 1.67 g/cm³, melting point 48°C (pentahydrate); highly soluble in water, hygroscopic. Produced by boiling sodium sulfite with sulfur.
Sodium Thiosulfate
Used in photography as fixer, water treatment for dechlorination, gold mining, medical antidote for cyanide, and textiles.
Low toxicity but irritates eyes, skin; releases toxic gases in fire. Avoid oxidizers; use PPE.
In 25kg bags or drums; rinse triply for recycling or reconditioning.
