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Hexamethyl phosphoramide

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Synonyms & Trade Names
Hexamethylphosphoric triamide, Hexamethylphosphorotriamide, HMPA, Tris(dimethylamino)phosphine oxide
CAS No.
680-31-9
RTECS No.
TD0875000
DOT ID & Guide
Formula
[(CH₃)₂N]₃PO
Conversion
IDLH
Ca [N.D.]
See: IDLH INDEX
Exposure Limits
NIOSH REL
Ca See Appendix A
OSHA PEL
none
Measurement Methods
None available
See: NMAM or OSHA Methods
Physical Description
Clear, colorless liquid with an aromatic or mild, amine-like odor. [Note: A solid below 43°F.]
Molecular Weight
179.2
Boiling Point
451°F
Freezing Point
43°F
Solubility
Miscible
Vapor Pressure
0.03 mmHg
Ionization Potential
?
Specific Gravity
1.03
Flash Point
220°F
Upper Explosive Limit
?
Lower Explosive Limit
?
Class IIIB Combustible Liquid: Fl.P. at or above 200°F.
Incompatibilities & Reactivities
Oxidizers, strong acids, chemically-active metals (e.g., potassium, sodium, magnesium, zinc)
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]
Personal Protection/Sanitation
(See protection codes)
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

Important additional information about respirator selection

See also
INTRODUCTION   ICSC CARD: 0162
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health