Chemical Safety Data Sheet MSDS / SDS
Osmium tetroxide
Revision Date:2026-03-21Revision Number:1
Product identifier
- Product name: Osmium tetroxide
- CBnumber: CB0853316
- CAS: 20816-12-0
- EINECS Number: 244-058-7
- Synonyms: OsO4;OSMIUM(VIII) OXIDE
Relevant identified uses of the substance or mixture and uses advised against
- Relevant identified uses: For R&D use only. Not for medicinal, household or other use.
- Uses advised against: none
Company Identification
- Company: Chemicalbook
- Address: Building 1, Huihuang International, Shangdi 10th Street, Haidian District, Beijing
- Telephone: 010-86108875
GHS Label elements, including precautionary statements
-
Symbol(GHS)
- Signal wordDanger
P260 Do not breathe dust/fume/gas/mist/vapours/spray.
P270 Do not eat, drink or smoke when using this product.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P303+P361+P353 IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.
P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.
Hazard statements
H314 Causes severe skin burns and eye damage
Substance
- Product name: Osmium tetroxide
- Synonyms: OsO4;OSMIUM(VIII) OXIDE
- CAS: 20816-12-0
- EC number: 244-058-7
- MF: O4Os
- MW: 254.23
First Aid Measures
General adviceImmediate medical attention is required.
Eye contact
Keep eye wide open while rinsing. Immediate medical attention is required. Rinse immediately with plenty of water, also under the eyelids, for at least 15 minutes. Do not ru affected area.
Skin Contact
Immediate medical attention is required. Wash off immediately with soap and plenty of water while removing all contaminated clothes and shoes.
Inhalation
Remove to fresh air Call a physician or poison control center immediately If not breathing, give artificial respiration If breathing is difficult, give oxygen
Ingestion
Do NOT induce vomiting. Never give anything by mouth to an unconscious person. Drink plenty of water. Immediate medical attention is required. Remove from exposure, lie down.
Clean mouth with water and drink afterwards plenty of water. Call a physician or poison control center immediately.
Self-protection of the first aider
Clean mouth with water and drink afterwards plenty of water. Call a physician or poison control center immediately.
Use personal protective equipment as required. Avoid contact with skin, eyes or clothing.
Most important symptoms and effects, both acute and delayed
SymptomsNo information available.
Indication of any immediate medical attention and special treatment needed
Note to physiciansProduct is a corrosive material. Use of gastric lavage or emesis is contraindicated.
Possible perforation of stomach or esophagus should be investigated. Do not give chemical antidotes. Asphyxia from glottal edema may occur. Marked decrease in blood pressure may occur with moist rales, frothy sputum, and high pulse pressure. Treat symptomatically.
Possible perforation of stomach or esophagus should be investigated. Do not give chemical antidotes. Asphyxia from glottal edema may occur. Marked decrease in blood pressure may occur with moist rales, frothy sputum, and high pulse pressure. Treat symptomatically.
Suitable Extinguishing Media
Suitable Extinguishing MediaUse extinguishing measures that are appropriate to local circumstances and the surrounding environment.
Unsuitable Extinguishing Media
None.
Specific hazards arising from the chemical
Specific hazards arising from the chemicalThe product causes burns of eyes, skin and mucous membranes. Thermal decomposition can lead to release of irritating and toxic gases and vapors. In the event of fire and/or explosion do not breathe fumes.
Hazardous combustion products
No information available.
Explosion data
Sensitivity to Mechanical ImpactNo information available.
Sensitivity to Static Discharge
No information available.
Protective equipment and precautions for firefighters
Protective equipment and precautions Wear self-contained breathing apparatus and protective suit.
for firefighters
for firefighters
NFPA 704
2
0
0
| HEALTH | 2 | Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury (e.g. diethyl ether, ammonium phosphate, iodine) | |
| FIRE | 0 | Materials that will not burn under typical fire conditions, including intrinsically noncombustible materials such as concrete, stone, and sand. Materials that will not burn in air when exposed to a temperature of 820 °C (1,500 °F) for a period of 5 minutes.(e.g. Carbon tetrachloride) | |
| REACT | 0 | Normally stable, even under fire exposure conditions, and is not reactive with water (e.g. helium,N2) | |
| SPEC. HAZ. |
Personal precautions, protective equipment and emergency procedures
Personal precautionsUse personal protective equipment as required. Evacuate personnel to safe areas. Avoid contact with skin, eyes or clothing. Keep people away from and upwind of spill/leak.
Environmental precautions
Environmental precautionsDo not allow into any sewer, on the ground or into any body of water. Should not be released into the environment. Prevent further leakage or spillage if safe to do so. Prevent product from entering drains. See Section 12 for additional Ecological Information.
Methods and material for containment and cleaning up
Methods for containmentPrevent further leakage or spillage if safe to do so. Cover powder spill with plastic sheet or tarp to minimize spreading. Dike far ahead of liquid spill for later disposal.
Methods for cleaning up
Take up mechanically, placing in appropriate containers for disposal. Clean contaminated surface thoroughly. Use personal protective equipment as required. Cover powder spill with plastic sheet or tarp to minimize spreading and keep powder dry. Avoid creating dust. Dam up. After cleaning, flush away traces with water.
Precautions for safe handling
Advice on safe handlingAvoid contact with skin, eyes or clothing. Use personal protective equipment as required.
Ensure adequate ventilation, especially in confined areas. In case of insufficient ventilation, wear suitable respiratory equipment. Use only with adequate ventilation and in closed systems. May cause damage to organs through prolonged or repeated exposure. Noxious vapor/odor.
Ensure adequate ventilation, especially in confined areas. In case of insufficient ventilation, wear suitable respiratory equipment. Use only with adequate ventilation and in closed systems. May cause damage to organs through prolonged or repeated exposure. Noxious vapor/odor.
Conditions for safe storage, including any incompatibilities
Storage ConditionsKeep container tightly closed in a dry and well-ventilated place. Keep out of the reach of children. Keep containers tightly closed in a dry, cool and well-ventilated place. Keep in properly labeled containers. Store at room temperature.
Incompatible materials
Incompatible with strong acids and bases. Incompatible with oxidizing agents.
Control parameters
Exposure Guidelines.
Other Information
Vacated limits revoked by the Court of Appeals decision in AFL-CIO v. OSHA, 965 F.2d 962 (11th Cir., 1992).
| Chemical Name | ACGIH TLV | OSHA PEL | NIOSH IDLH |
|---|---|---|---|
| Osmium tetroxide 20816-12-0 | STEL: 0.0006 ppm Os TWA: 0.0002 ppm Os | TWA: 0.002 mg/m3 Os (vacated) TWA: 0.0002 ppm Os (vacated) TWA: 0.002 mg/m3 Os (vacated) STEL: 0.0006 ppm Os (vacated) STEL: 0.006 mg/m3 Os | IDLH: 1 mg/m3 TWA: 0.0002 ppm TWA: 0.002 mg/m3 STEL: 0.0006 ppm STEL: 0.006 mg/m3 |
Appropriate engineering controls
Engineering ControlsEnsure adequate ventilation, especially in confined areas
Individual protection measures, such as personal protective equipment
Eye/face protectionTight sealing safety goggles. Face protection shield.
Skin and Body Protection
Wear protective gloves and protective clothing.
Respiratory protection
If exposure limits are exceeded or irritation is experienced, NIOSH/MSHA approved respiratory protection should be worn. Positive-pressure supplied air respirators may be required for high airborne contaminant concentrations. Respiratory protection must be provided in accordance with current local regulations.
General Hygiene Considerations
When using do not eat, drink or smoke. Wash contaminated clothing before reuse. Keep away from food, drink and animal feeding stuffs. Contaminated work clothing should not be allowed out of the workplace. Regular cleaning of equipment, work area and clothing is recommended. Avoid contact with skin, eyes or clothing. Take off all contaminated clothing and wash it before reuse. Wear suitable gloves and eye/face protection.
Information on basic physicochemical properties
- Physical StateSolid
- Appearancepowder
- OdorAcrid, chlorine-like odor detectable at 2 ppm (20 mg/m3)
- pH6 (20°C, 25g/L in H2O)
- Melting point/freezing point39.5 °C
- Boiling point130 °C
- Flash point-40 °C
- Density4.9 g/cm3
- Evaporation rateNo information available
- Upper flammability limitsNo information available
- Lower flammability limitNo information available
- Vapor pressure7
- Vapor density8.8
- Specific gravity5.0
- Water solubilitySoluble in chloroform, alcohol and ethers.Soluble in water, organic solvents, benzene, alcohol, ether, ammonium hydroxide, phosphorus oxychloride and carbon tetrachloride.
- Solubility in other solventsNo information available
- Partition coefficientNo information available
- Autoignition temperatureNo information available
- Decomposition temperatureNo information available
- Kinematic viscosityNo information available
- Explosive propertiesNo information available
- Oxidizing propertiesNo information available
- SolubilitySoluble in alcohol, ether, chloroform, benzene, ammonium hydroxide, phosphorus oxychloride and carbon tetrachloride
- ColourWhite to yellow,or lemon yellow
Reactivity
Not applicable
Chemical stability
Stable under recommended storage conditions.
Possibility of Hazardous Reactions
None under normal processing.
Hazardous polymerization
No information available.
Conditions to avoid
Exposure to air or moisture over prolonged periods.
Incompatible materials
Incompatible with strong acids and bases. Incompatible with oxidizing agents.
Hazardous Decomposition Products
Thermal decomposition can lead to release of irritating and toxic gases and vapors.
Information on likely routes of exposure
InhalationClassified based on available data. For more details, see section 2.
Eye contact
Classified based on available data. For more details, see section 2.
Skin Contact
Classified based on available data. For more details, see section 2.
Ingestion
Classified based on available data. For more details, see section 2.
Information on toxicological effects
SymptomsClassified based on available data. For more details, see section 2.
Delayed and immediate effects as well as chronic effects from short and long-term exposure
Chronic ToxicityChronic exposure to corrosive fumes/gases may cause erosion of the teeth followed by jaw necrosis. Bronchial irritation with chronic cough and frequent attacks of pneumonia are common. Gastrointestinal disturbances may also be seen. Avoid repeated exposure. Possible risk of irreversible effects. Target Organ Effects Eyes, Respiratory system, Skin.
Numerical measures of toxicity - Product Information
Unknown acute toxicityClassified based on available data. For more details, see section 2
The following values are calculated based on chapter 3.1 of the GHS document
ATEmix (oral)
The following values are calculated based on chapter 3.1 of the GHS document
5 mg/kg
ATEmix (dermal)
5 mg/kg
ATEmix (inhalation-dust/mist)
0 mg/l
Ecotoxicity
May cause long lasting harmful effects to aquatic life
100% of the mixture consists of components(s) of unknown hazards to the aquatic environment.
100% of the mixture consists of components(s) of unknown hazards to the aquatic environment.
Persistence and degradability
No information available.
Bioaccumulation
No information available.
Mobility
No information available.
Disposal of wastes
Should not be released into the environment. Disposal should be in accordance with applicable regional, national and local laws and regulations.
Contaminated packaging
Do not reuse container.
Other Information
Waste codes should be assigned by the user based on the application for which the product was used.
US EPA Waste Number
P087
California Hazardous Waste Status
This product contains one or more substances that are listed with the State of California as a hazardous waste.
| Chemical Name | California Hazardous Waste Status |
|---|---|
| Osmium tetroxide 20816-12-0 | Toxic |
DOT
UN/ID noUN2471
Hazard Class
6.1
Packing Group
I
Proper shipping name
Osmium tetroxide
Description
UN2471, Osmium tetroxide, 6.1, I, Marine pollutant, POISON Marine pollutant This product contains a chemical which is listed as a severe marine pollutant according to DOT
Emergency Response Guide Number
154
IMDG
UN/ID noUN2471
Hazard Class
6.1 Subsidiary hazard class P
Packing Group
I
Proper shipping name
Osmium tetroxide
Description
UN2471, Osmium tetroxide, 6.1 (P), I, Marine pollutant
EmS-No
F-A, S-A Marine pollutant This product contains a chemical which is listed as a marine pollutant according to IMDG/IMO
IATA
UN/ID noUN2471
Hazard Class
6.1
Packing Group
I
Proper shipping name
Osmium tetroxide
Description
UN2471, Osmium tetroxide, 6.1, I
International Inventories
All of the components in the product are on the following Inventory lists
TSCA (United States): Canada (DSL/NDSL) Europe (EINECS/ELINCS/NLP) Australia (AICS) South Korea (KECL): China (IECSC)
X - Listed
Philippines (PICCS)
TSCA - United States Toxic Substances Control Act Section 8(b) Inventory
DSL/NDSL - Canadian Domestic Substances List/Non-Domestic Substances List
EINECS/ELINCS - European Inventory of Existing Chemical Substances/European List of Notified Chemical Substances
ENCS - Japan Existing and New Chemical Substances
IECSC - China Inventory of Existing Chemical Substances
KECL - Korean Existing and Evaluated Chemical Substances
PICCS - Philippines Inventory of Chemicals and Chemical Substances
TSCA (United States): Canada (DSL/NDSL) Europe (EINECS/ELINCS/NLP) Australia (AICS) South Korea (KECL): China (IECSC)
X - Listed
Philippines (PICCS)
TSCA - United States Toxic Substances Control Act Section 8(b) Inventory
DSL/NDSL - Canadian Domestic Substances List/Non-Domestic Substances List
EINECS/ELINCS - European Inventory of Existing Chemical Substances/European List of Notified Chemical Substances
ENCS - Japan Existing and New Chemical Substances
IECSC - China Inventory of Existing Chemical Substances
KECL - Korean Existing and Evaluated Chemical Substances
PICCS - Philippines Inventory of Chemicals and Chemical Substances
| Chemical name | TSCA | DSL | NDSL | EINECS | ELINCS | ENCS | IECSC | KECL | PICCS | AICS |
|---|---|---|---|---|---|---|---|---|---|---|
| Osmium tetroxide | X | X | - | X | - | - | X | X | X | X |
US Federal Regulations
SARA 313
Section 313 of Title III of the Superfund Amendments and Reauthorization Act of 1986 (SARA). This product does not contain any chemicals which are subject to the reporting requirements of the Act and Title 40 of the Code of Federal Regulations, Part 372.
SARA 311/312 Hazard Categories
Acute health hazardYes
Chronic Health Hazard
Yes
Fire hazard
No
Sudden release of pressure hazard
No
Reactive hazard
No
CWA (Clean Water Act)
This product does not contain any substances regulated as pollutants pursuant to the Clean Water Act (40 CFR 122.21 and 40
CFR 122.42).
CFR 122.42).
US State Regulations
California Proposition 65
This product does not contain any Proposition 65 chemicals.
U.S. State Right-to-Know Regulations
| Chemical Name | New Jersey | Massachusetts | Pennsylvania |
|---|---|---|---|
| Osmium tetroxide 20816-12-0 | X | X | X |
Abbreviations and acronyms
CAS: Chemical Abstracts Service
TWA: Time-Weighted Average
STEL: Short-Term Exposure Limit
LD50: Lethal Dose 50%
LC50: Lethal Concentration 50%
EC50: Effective Concentration 50%
PEL: Permissible Exposure Limit
TLV: Threshold Limit Value
IMDG: International Maritime Dangerous Goods Code
IATA: International Air Transport Association
ADR: European Agreement concerning the International Carriage of Dangerous Goods by Road
DOT: US Department of Transportation
NFPA: National Fire Protection Association
NIOSH: National Institute for Occupational Safety and Health
OSHA: Occupational Safety and Health Administration
TWA: Time-Weighted Average
STEL: Short-Term Exposure Limit
LD50: Lethal Dose 50%
LC50: Lethal Concentration 50%
EC50: Effective Concentration 50%
PEL: Permissible Exposure Limit
TLV: Threshold Limit Value
IMDG: International Maritime Dangerous Goods Code
IATA: International Air Transport Association
ADR: European Agreement concerning the International Carriage of Dangerous Goods by Road
DOT: US Department of Transportation
NFPA: National Fire Protection Association
NIOSH: National Institute for Occupational Safety and Health
OSHA: Occupational Safety and Health Administration
Disclaimer:
The information in this MSDS is only applicable to the specified product, unless otherwise specified, it is not applicable to the mixture of this product and other substances. This MSDS only provides information on the safety of the product for those who have received the appropriate professional training for the user of the product. Users of this MSDS must make independent judgments on the applicability of this SDS. The authors of this MSDS will not be held responsible for any harm caused by the use of this MSDS.