NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Propylene imine



Synonyms & Trade Names

2-Methylaziridine, 2-Methylethyleneimine, Propyleneimine, Propylene imine (inhibited), Propylenimine
DOT ID & Guide
1921 / 131P (inhibited)


NIOSH REL: Ca TWA 2 ppm (5 mg/m3) [skin] See Appendix A
OSHA PEL: TWA 2 ppm (5 mg/m3) [skin]
Ca [100 ppm] See: 75558
1 ppm = 2.34 mg/m3
Physical Description
Colorless, oily liquid with an ammonia-like odor.
MW: 57.1
BP: 152°F
FRZ: -85°F
Sol: Miscible
VP: 112 mmHg
IP: 9.00 eV

Sp.Gr: 0.80
Fl.P: 25°F
UEL: ?
LEL: ?

Class IB Flammable Liquid: Fl.P. below 73F and BP at or above 100F.
Incompatibilities & Reactivities

Acids, strong oxidizers, water, carbonyl compounds, quinones, sulfonyl halides [Note: Subject to violent polymerization in contact with acids. Hydrolyzes in water to form methylethanolamine.]
Measurement Methods
None available
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet (flammable)
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
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
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern/Any appropriate escape-type, self-contained breathing apparatus
Important additional information about respirator selection
Exposure Routes
inhalation, skin absorption, ingestion, skin and/or eye contact
Eye, skin burns; [potential occupational carcinogen]
Target Organs
Eyes, skin

Cancer Site
[in animals: nasal tumors]
See also: INTRODUCTION   See ICSC CARD: 0322   See MEDICAL TESTS: 0199