NIOSH Pocket Guide to Chemical Hazards

Hexamethyl phosphoramide CAS 680-31-9
[(CH3)2N]3PO RTECS TD0875000
Synonyms & Trade Names
Hexamethylphosphoric triamide, Hexamethylphosphorotriamide, HMPA, Tris(dimethylamino)phosphine oxide
DOT ID & Guide
NIOSH REL: Ca See Appendix A
OSHA PEL: none
IDLH Ca [N.D.] Conversion
Physical Description
Clear, colorless liquid with an aromatic or mild, amine-like odor. [Note: A solid below 43°F.]
MW: 179.2
BP: 451°F
FRZ: 43°F
Sol: Miscible
VP: 0.03 mmHg
IP: ?

Sp.Gr: 1.03
Fl.P: 220°F
UEL: ?
LEL: ?

Class IIIB Combustible Liquid: Fl.P. at or above 200F.
Incompatibilities & Reactivities
Oxidizers, strong acids, chemically-active metals (e.g., potassium, sodium, magnesium, zinc)
Measurement Methods
None available
Personal Protection & Sanitation
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet or contaminated
Change: No recommendation
Provide: Eyewash, Quick drench
First Aid (See procedures)
Eye: Irrigate immediately
Skin: Water flush immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure- demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, respiratory system; dyspnea (breathing difficulty); abdominal pain; [potential occupational carcinogen]
Target Organs Eyes, skin, respiratory system, central nervous system, gastrointestinal tract

Cancer Site [in animals: cancer of the nasal cavity]