1. OSHA Occupational Chemical Database
  2. HEXAMETHYL PHOSPHORAMIDE
Label abbreviations descriptions

HEXAMETHYL PHOSPHORAMIDE

Chemical Identification
Chemical Identification
CAS # 680-31-9
Formula

C₆H₁₈N₃OP
Synonyms

hexamethylphosphoric acid triamide; hexamethylphosphorotriamide; HMPA; tris(dimethylamino)phosphine oxide; HEMPA; HMPT
Physical Properties
Physical Properties
Physical description Clear, colorless to light amber liquid with an aromatic or mild, amine-like odor.
Boiling point 451°F Molecular weight 179.2
Freezing point/melting point 43°F Vapor pressure 0.03 mmHg
Flash point 220°F Vapor density 6.18
Specific gravity 1.024 Ionization potential
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
 

 

 REL-TWA
 

 

 TLV-TWA
 

No TLV value [1990]

 PEL-TWA
 

 
PEL-STEL
 

 

 REL-STEL
 

 

 TLV-STEL
 

 

 PEL-STEL
 

 
PEL-C
 

 

 REL-C
 

 

 TLV-C
 

 

 PEL-C
 

 
Skin notation
 

NA

 Skin notation
 

N

 Skin notation
 

Y

 Skin notation
 

NA
Notes:
 

Not established

 Notes:
 

CARCINOGEN (Ca): REDUCE EXPOSURE TO LOWEST FEASIBLE CONCENTRATION. See Appendix A, NIOSH Potential Occupational Carcinogens.

 Notes:
 

 

 Notes:
 

Not established
Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: NTP-R,IARC-2B, NIOSH-Ca, TLV-A3 Notes:
 

Ca
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 

 
Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Hexamethylphosphoramide

NIOSH: Pocket Guide to Chemical Hazards - Hexamethyl phosphoramide

Literature References

 
  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Hexamethyl phosphoramide. See annual publication for most recent information.

Last Updated Date : 01/28/2021