CAS 75-21-8: Ethylene Oxide (C2H4O)

Identity

CAS Number	75-21-8
Molecular Formula	C2H4O
IUPAC Name	oxirane
Molecular Weight	44.05 g/mol
SMILES	`C1CO1`
Synonyms	ethylene oxide, oxirane, epoxyethane, EO, dimethylene oxide

2D Structure

Physical Properties

Density	0.882 g/mL at 25°C
Boiling Point	10.7°C
Melting Point	-111.0°C
Flash Point	-20.0°C
Vapor Pressure	146.0 kPa at 20°C
Refractive Index	nD = 1.36
Dielectric Constant	ε = 13.0

Safety & GHS Classification

FlammableGHS05GHS06Health Hazard

H220: Extremely flammable gas
H301: Toxic if swallowed
H314: Causes severe skin burns and eye damage
H331: Toxic if inhaled
H335: May cause respiratory irritation
H340: May cause genetic defects
H350: May cause cancer
H361: Suspected of damaging fertility or the unborn child

Storage: Store as compressed gas in cool, well-ventilated area. Extremely flammable gas — keep away from all ignition sources. Ground/bond containers. Use explosion-proof equipment. Store in dedicated gas cabinet. Highly reactive — polymerization hazard. Monitor temperature and pressure.