Agent Name |
Osmium tetroxide |
CAS Number |
20816-12-0 |
Formula |
O4-Os |
Major Category |
Metals |
Synonyms |
Osmic acid; Osmic acid anhydride; Osmium tetraoxide; Osmium tetroxide; Perosmic acid anhydride; Perosmic oxide; [ChemIDplus] UN2471 |
Category |
Metals, Inorganic Compounds |
Description |
Colorless, crystalline solid or pale-yellow mass with an unpleasant, acrid, chlorine-like odor; Note: A liquid above 105 degrees F; [NIOSH] |
Sources/Uses |
Used primarily for staining of biological and pathological tissues for microscopic study; [ACGIH] |
Comments |
A skin and respiratory irritant, OsO4 can cause pulmonary edema in animals exposed to high concentrations. [ACGIH] A lachrymator; [ChemFinder] "Tear drawing" and corrosive to the skin, eyes, and respiratory tract; May cause kidney injury after prolonged or repeated exposure; [ICSC] Osmium tetroxide can cause chronic bronchitis. [LaDou, p. 330] May cause severe burns; [CAMEO] Based on animal studies, osmium tetroxide bioaccumulates after chronic exposure and may cause kidney and liver damage. [HSDB] |
Exposure Assessment |
Skin Designation (ACGIH) |
No |
Bioaccumulates |
Yes |
TLV (ACGIH) |
0.0016 mg/m3 |
STEL (ACGIH) |
0.0047 mg/m3 |
PEL (OSHA) |
0.002 mg/m3, as Os |
IDLH (NIOSH) |
1 mg/m3, as Os |
Excerpts from Documentation for IDLHs |
It has been suggested that 1 mg/m3 is tolerable for 30 minutes [Flury and Zernik 1931]. Workers exposed to 0.1 to 0.6 mg/m3 suffered from lacrimation and disturbances of vision and in some cases, headache, conjunctivitis, and cough [McLaughlin et al. 1946]. |
Vapor Pressure |
7 mm Hg |
Odor Threshold Low |
0.0019 ppm |
Lethal Concentration |
LCLo (rats) = 40 ppm/4H |
Explanatory Notes |
Odor threshold from NJ "Hazardous Substance Fact Sheet"; |
Reference Link |
International Chemical Safety Cards (WHO/IPCS/ILO) |
Adverse Effects |
Toxic Pneumonitis |
Yes |
Chronic Bronchitis |
Yes |
Dermatotoxin |
Skin Burns |
Lacrimator |
Yes |
Hepatotoxin |
Hepatotoxin, Secondary |
Nephrotoxin |
Yes |
Links to Other NLM Databases |
Health Studies |
Human Health Effects from Hazardous Substances Data Bank: OSMIUM TETROXIDE
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