Melting point :−135 °C(lit.)
Boiling point :44-46 °C(lit.)
Density :0.771 g/mL at 25 °C(lit.)
vapor pressure :20.89 psi ( 55 °C)
refractive index :n20/D 1.421(lit.)
Flash point :<−30 °F
storage temp. :0-6°C
solubility :water: soluble0.535g/L at 25°C
form :Liquid
color :Colorless
Specific Gravity :0.771
Water Solubility :immiscible
Thermal Conductivity :0.122 W/(m·K) at 25 ℃
Sensitive :Air Sensitive
BRN :635707
Henry's Law Constant :6.3 x 10^-2 atmm³/mol at 25 °C (Hine and Mookerjee, 1975)
Stability :Stable. Highly flammable. Incompatible with strong oxidizing agents. Store cold.
InChI :1S/C5H8/c1-2-4-5-3-1/h1-2H,3-5H2
InChIKey :LPIQUOYDBNQMRZ-UHFFFAOYSA-N
SMILES :C1CC=CC1
LogP :2.47 at 25℃
CAS DataBase Reference :142-29-0(CAS DataBase Reference)
NIST Chemistry Reference :Cyclopentene(142-29-0)
EPA Substance Registry System :Cyclopentene (142-29-0)

Symbol(GHS):
Signal word:	Danger
Hazard statements:	Code Hazard statements Hazard class Category Signal word Pictogram P-Codes H225 Highly Flammable liquid and vapour Flammable liquids Category 2 Danger P210,P233, P240, P241, P242, P243,P280, P303+ P361+P353, P370+P378,P403+P235, P501 H315 Causes skin irritation Skin corrosion/irritation Category 2 Warning P264, P280, P302+P352, P321,P332+P313, P362 H319 Causes serious eye irritation Serious eye damage/eye irritation Category 2A Warning P264, P280, P305+P351+P338,P337+P313P
Precautionary statements:	P210 Keep away from heat/sparks/open flames/hot surfaces. — No smoking. P233 Keep container tightly closed. P240 Ground/bond container and receiving equipment. P241 Use explosion-proof electrical/ventilating/lighting/…/equipment. P242 Use only non-sparking tools. P243 Take precautionary measures against static discharge. P264 Wash hands thoroughly after handling. P264 Wash skin thouroughly after handling. P270 Do not eat, drink or smoke when using this product. P280 Wear protective gloves/protective clothing/eye protection/face protection. P303+P361+P353 IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower. P305+P351+P338 IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing. P332+P313 IF SKIN irritation occurs: Get medical advice/attention. P337+P313 IF eye irritation persists: Get medical advice/attention. P370+P378 In case of fire: Use … for extinction. P403+P235 Store in a well-ventilated place. Keep cool. P501 Dispose of contents/container to..…