CAS 71-43-2: Benzene (C6H6)

Identity

CAS Number	71-43-2
Molecular Formula	C6H6
IUPAC Name	benzene
Molecular Weight	78.11 g/mol
SMILES	`c1ccccc1`
Synonyms	benzol, cyclohexatriene, phenyl hydride, PhH

2D Structure

Physical Properties

Density	0.879 g/mL at 25°C
Boiling Point	80.1°C
Melting Point	5.5°C
Flash Point	-11.0°C
Vapor Pressure	12.7 kPa at 20°C
Refractive Index	nD = 1.501
Dielectric Constant	ε = 2.3

Safety & GHS Classification

FlammableGHS06Health Hazard

H225: Highly flammable liquid and vapor
H304: May be fatal if swallowed and enters airways
H315: Causes skin irritation
H319: Causes serious eye irritation
H340: May cause genetic defects
H350: May cause cancer
H372: Causes damage to organs through prolonged or repeated exposure (blood)
H411: Toxic to aquatic life with long lasting effects

Storage: Known human carcinogen (leukemia). Store in flammable liquid storage cabinet. Use only in fume hood with strict exposure controls. Minimize all skin contact and inhalation. Many jurisdictions restrict or ban benzene use in laboratories — substitute with toluene when possible.