Agent Name

Sodium omadine

CAS Number

15922-78-8; 3811-73-2



Major Category

Other Uses


15922-78-8: Pyrithione sodium; 1-Hydroxy-2(1H)-pyridinethionato sodium; 1-Hydroxy-2(1H)-pyridinethione, sodium salt; AL02725; Omacide 24; Omadine-sodium; SQ 3277; Sel de sodium de 1-hydroxy-2 (1H)-pyridinethione [French]; Sodium 1-hydroxypyridine-2-thione; Sodium 2-pyridinethiol-1-oxide; Sodium Omadine; Sodium pyrithione; 2(1H)-Pyridinethione, 1-hydroxy-, sodium; [ChemIDplus] 3811-73-2: 2-Pyridinethiol, 1-oxide, sodium salt; Sodium (2-pyridylthio)-N-oxide; Sodium pyrithione; (1-Hydroxy-2-pyridinethione), sodium salt; (1-Hydroxy-2-pyridinethione), sodium salt, tech.; 1-Oxo-2-pyridinethiol sodium salt; 2-Mercaptopyridine 1-oxide sodium salt; 2-Mercaptopyridine oxide sodium salt; 2-Mercaptopyridine-N-oxide sodium salt; 2-Pyridinethiol N-oxide sodium salt; 2-Pyridinethiol-1-oxide sodium salt; Omadine sodium; Sodium (2-pyridylthio)-N-oxide; Sodium 2-mercaptopyridine 1-oxide; Sodium 2-pyridinethiol 1-oxide; Sodium 2-pyridinethiol N-oxide; Sodium 2-pyridinethiolate 1-oxide; Sodium omadine (VAN); Sodium, (2-pyridinylthio)-, N-oxide; Thione (reagent); [ChemIDplus]




Technical product is off-white solid; Formulated as liquid soluble concentrates; [Reference #1] 3811-73-2: Hygroscopic crystalline powder with a stench; [Alfa Aesar MSDS]


Used as biocide (controls slime forming bacteria and fungi) in aqueous functional fluids (metalworking, cutting, cooling, and lubricating), latex emulsions (adhesives, caulks, patching compounds, sealants, pastes, and grouts), aqueous fiber lubricants and inks, jet-printer inks, laundry rinse additives and detergents, carpet cleaners, analytical and diagnostic reagents; Also used as in-can preservative for water based mixtures used in making concrete (not covered in this RED); [Reference #1]


A mixture of two tautomers: 1-hydroxy-2(1H)-pyridinethione, sodium salt (15922-78-8) and 2-pyridinethio-1-oxide, sodium salt (3811-73-2); Not a skin sensitizer in guinea pig or human studies; Minimum to marked hind-limb atrophy observed in 13-week gavage study of rats at highest tested dose of 8 mg/kg/day (LOEL of 2 mg/kg/day based on evidence of neurotoxicity); [Reference #1] 3811-73-2: A skin and strong eye irritant; Harmful by ingestion; [Alfa Aesar MSDS]

Reference Link

EPA Pesticide Chemical Search

Exposure Assessment

1 mg/m3, inhalable fraction

Vapor Pressure

7.0E-8 mm Hg

Lethal Concentration

LC50 (rat) = 1,080 mg/m3/4hr

Adverse Effects

Other CNS Neurotoxin

Links to Other NLM Databases
Toxicity Information


Chemical Information

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Related Information in HazMap

Industrial Processes with risk of exposure: