Molecular Formula:C₃H₇N
Molecular Weight:57.11
Melting Point: -65°C 
EINECS: 200-878-7
Flash Point: -4°C
Density: 0.824 g/cm³
Refractive index: 1.4125
Water Solubility: miscible  
IUPAC Name: 2-Methylaziridine
Boiling Point: 66.5 °C at 760 mmHg 
Vapour Pressure: 151 mmHg at 25°C 
Appearance: Colorless, oily liquid with an ammonia-like odor
Air & Water Reactions: Soluble in water. Reacts slowly and non hazardously with water to form propanolamine or methylethanolamine.
Stability: Unstable - readily polymerises in the absence of an inhibitor. May polymerize vigorously or explosively in the presence of acids. Flammable. Incompatible with acids, oxidizing agents, quinones, carbonyl compounds, sulfonyl halides, some types of plastic, water.
Synonyms: PI ; Propyleneimine ; 2-Methylaziridine ; (R,S)-2-Methyl-aziridine ; 1,2-Propyleneimine ; 1,2-Propylenimine ; 1,2-Propylenimine(2-methylaziridine) ; 2-Methylazacyclopropane
Following is the molecular structure of Propylenei mine (75-55-8):

 Propylenei mine (75-55-8) is used as an organic intermediate.

Reactivity Profile: Propyleneimine (75-55-8) is subject to violent polymerization on contact with an acid. (The inhibitor is intended to prevent polymerization). Incompatible with isocyanates, halogenated organics, peroxides, phenols (acidic), epoxides, anhydrides, and acid halides. Flammable gaseous hydrogen is generated in combination with strong reducing agents, such as hydrides.

NTP 10th Report on Carcinogens. IARC Cancer Review: Group 2B IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 7 ,1987,p. 56.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Limited Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 9 ,1975,p. 61.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . EPA Genetic Toxicology Program. Reported in EPA TSCA Inventory. EPA Extremely Hazardous Substances List. Community Right-To-Know List.

Confirmed carcinogen with experimental carcinogenic data. Poison by ingestion and skin contact. Moderately toxic by inhalation. Mutation data reported. Severe eye irritant. Implicated as a brain carcinogen. A flammable liquid and very dangerous fire hazard when exposed to heat or flame; can react vigorously with oxidizing materials. Polymerizes explosively on exposure to acids or acid fumes. A storage hazard. When heated to decomposition it emits toxic fumes of NO_x.
Safety data of Propylenei mine (75-55-8):
Hazard Codes: F;T+;N,T
F: Highly Flammable T: Toxic   
 N: Dangerous for the environment   T+: Very Toxic
Risk Statements: 45-11-26/27/28-41-51/53
45: May cause cancer 
11: Highly Flammable 
26/27/28: Very Toxic by inhalation, in contact with skin and if swallowed 
41: Risk of serious damage to eyes 
51/53: Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment
Safety Statements: 53-45-61
53: Avoid exposure - obtain special instruction before use 
45: In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) 
61: Avoid release to the environment. Refer to special instructions safety data sheet  
RIDADR: 1921
RTECS: CM8050000
HazardClass: 3.1
PackingGroup: I

OSHA PEL: TWA 2 ppm (skin)
ACGIH TLV: TWA 2 ppm (skin); Animal Carcinogen
DFG MAK: Animal Carcinogen, Suspected Human Carcinogen
DOT Classification:  3; Label: Flammable Liquid