OSMIUM TETROXIDE†

Chemical Identification
Chemical Identification
CAS # 20816-12-0
Formula

O₄Os

Synonyms

osmic acid anhydride; osmium oxide

Physical Properties
Physical Properties
Physical description Colorless, crystalline solid or pale-yellow mass with an unpleasant, acrid, chlorine-like odor.
Boiling point 266°F Molecular weight 254.2
Freezing point/melting point 105°F Vapor pressure 7 mmHg
Flash point Vapor density
Specific gravity 5.1 Ionization potential 12.60 eV
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating NFPA fire rating
NFPA reactivity rating NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.)
Sampling group
Sampler/Sampling media
Sampling time*
Sampling volume (TWA)*
Sampling flow rate (TWA)*
Sampling volume (STEL/Peak/C)*
Sampling flow rate (STEL/Peak/C)*
Analytical method instruments
Method reference
Notes
Special requirements

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
Bulk Method
Bulk Method
On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA

0.002 mg/m³

REL-TWA

0.0002 ppm (0.002 mg/m³)

TLV-TWA

0.0002 ppm [1979]

PEL-TWA

0.0002 ppm (0.002 mg/m³)

PEL-STEL REL-STEL

0.0006 ppm (0.006 mg/m³)

TLV-STEL

0.0006 ppm [1979]

PEL-STEL

0.0006 ppm (0.006 mg/m³)

PEL-C REL-C TLV-C PEL-C
Skin notation

N

Skin notation

N

Skin notation

N

Skin notation

N

Notes:

See 29 CFR 1910.1000 Table Z-1.

Notes: Notes: Notes:
Health factors:  See NIH-NLM PubChem. IDLH

1 mg/m³

Carcinogenic classifications: Not listed Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Osmium tetroxide

NIOSH: Pocket Guide to Chemical Hazards - Osmium tetroxide

Literature References

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Osmium tetroxide [20816-12-0], as Os. See annual publication for most recent information.

Last Updated Date : 01/31/2018