Melting point :323-329 °C(lit.)
Boiling point :34 °C(lit.)
Density :0.681 g/mL at 25 °C(lit.)
vapor density :2.35 (vs air)
vapor pressure :8.82 psi ( 20 °C)
refractive index :n20/D 1.422(lit.)
Flash point :−65 °F
storage temp. :Store at <= 20°C.
solubility :0.7g/l
form :solid
pka :>14 (Schwarzenbach et al., 1993)
color :Clear colorless to very pale yellow
Odor :petroleum-like odor
Odor Threshold :0.048ppm
explosive limit :1-9.7%(V)
Water Solubility :0.07 g/100 mL
FreezingPoint :-145.96℃
λmax :231nm(neat)(lit.)
Merck :14,5201
BRN :969158
Henry's Law Constant :(x 10^-2 atm?m³/mol): 3.45 at 18 °C (dynamic stripping cell-MS, Karl et al., 2003)
Dielectric constant :2.1（25℃）
Stability :Stability Extremely flammable. Readily forms explosive mixtures with air. Note low flash point, low boiling point, high vapour pressure. Unstable - prone to spontaneous polymerization. May contain a polymerization inhibitor. Incompatible with strong oxidizing agents.
LogP :2.42 at 20℃
CAS DataBase Reference :78-79-5(CAS DataBase Reference)
IARC :2B (Vol. 60, 71) 1999
NIST Chemistry Reference :1,3-Butadiene, 2-methyl-(78-79-5)
EPA Substance Registry System :Isoprene (78-79-5)

Symbol(GHS):
Signal word:	Danger
Hazard statements:	Code Hazard statements Hazard class Category Signal word Pictogram P-Codes H224 Extremely flammable liquid and vapour Flammable liquids Category 1 Danger H341 Suspected of causing genetic defects Germ cell mutagenicity Category 2 Warning P201,P202, P281, P308+P313, P405,P501 H350 May cause cancer Carcinogenicity Category 1A, 1B Danger H412 Harmful to aquatic life with long lasting effects Hazardous to the aquatic environment, long-term hazard Category 3 P273, P501
Precautionary statements:	P202 Do not handle until all safety precautions have been read and understood. P210 Keep away from heat/sparks/open flames/hot surfaces. — No smoking. P233 Keep container tightly closed. P273 Avoid release to the environment. P308+P313 IF exposed or concerned: Get medical advice/attention. P403+P233 Store in a well-ventilated place. Keep container tightly closed.