IUPAC Name: (Z)-2-Chlorobut-2-ene 
Molecular Formula: C₄H₇Cl
EINECS: 224-719-6
Transport Information: UN 1993
Molecular Weight: 90.55g/mol
Density: 0.911 g/cm³
Boiling Point: 70.6 °C at 760 mmHg
Flash Point: -19°C
Freely Rotating Bonds: 0
Polar Surface Area: 0 Å²
Index of Refraction: 1.423
Molar Refractivity: 25.33 cm³
Molar Volume: 99.3 cm³
Polarizability: 10.04 ×10^-24 cm³
Surface Tension: 21.1 dyne/cm 
Enthalpy of Vaporization: 29.92 kJ/mol
Vapour Pressure: 139 mmHg at 25°C
The Cas Register Number  of 2-Chloro-2-butene is 4461-41-0.The chemical synonyms of 2-Chloro-2-butene (CAS NO.4461-41-0) are 2-Chlorobutene-2 ; 2-Chloro-2-butene ;  2-Chlorobut-2-ene ; 2-Butene, 2-chloro- ; Trans-2-chloro-2-butene ; 2-Butene, 2-chloro-, (E)- .The molecular structure of  2-Chloro-2-butene (CAS NO.4461-41-0) is .

Low toxicity by inhalation. Mutation data reported. A dangerous fire hazard when exposed to heat or flame. When heated to decomposition it emits toxic fumes of Cl⁻. See also CHLORINATED HYDROCARBONS, ALIPHATIC.
Hazard Codes: F, Xi
Risk Statements: 11-36/37/38-36/37 
R11: Highly flammable. 
R36/37: Irritating to eyes and respiratory system.
R36/37/38: Irritating to eyes, respiratory system and skin. 
Safety Statements: 16-33-36/37/39-27-26 
S16: Keep away from sources of ignition. 
S33:Take precautionary measures against static discharges. 
S36/37/39: Wear suitable protective clothing, gloves and eye/face protection. 
S27: Take off immediately all contaminated clothing. 
S26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.
HazardClass: 3.1

Fire-extinguishing agent of 2-Chloro-2-butene (CAS NO.4461-41-0)  is foam, dry powder, carbon dioxide and water spray.