Propylene oxide

Propylene oxide
	Structural formula
	Ball-and-stick model of the propylene oxide molecule
Names
	Preferred IUPAC name (2R)-2-Methyloxirane; (2S)-2-Methyloxirane
	Other names Propylene oxide; Epoxypropane; Propylene epoxide; 1,2-Propylene oxide; Methyl oxirane; 1,2-Epoxypropane; Propene oxide; Methyl ethylene oxide; Methylethylene oxide
Identifiers
CAS Number	75-56-9 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:38685 ;
ChemSpider	6138;
ECHA InfoCard	100.000.800
EC Number	200-879-2;
KEGG	C15508 ;
PubChem CID	6378;
UNII	Y4Y7NYD4BK ;
CompTox Dashboard (EPA)	DTXSID5021207 ;
	InChI InChI=1S/C3H6O/c1-3-2-4-3/h3H,2H2,1H3 Key: GOOHAUXETOMSMM-UHFFFAOYSA-N;
	SMILES CC1CO1;
Properties
Chemical formula	C3H6O
Molar mass	58.080 g·mol−1
Appearance	Colourless liquid
Odor	benzene-like
Density	0.859 g/cm3
Melting point	−111.9 °C (−169.4 °F; 161.2 K)
Boiling point	35 °C (95 °F; 308 K)
Solubility in water	41% (20 °C)
Vapor pressure	445 mmHg (20 °C)
Magnetic susceptibility (χ)	−4.25×10−5 cm3/mol
Refractive index (nD)	1.3660
Thermochemistry
Heat capacity (C)	120.4 J·(K·mol)−1
Std molar; entropy (S⦵298)	196.5 J·(K·mol)−1
Std enthalpy of; formation (ΔfH⦵298)	−123.0 kJ·mol−1
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	Extremely flammable
	GHS labelling:
Pictograms
Signal word	Danger
NFPA 704 (fire diamond)	3 4 2
Flash point	−37 °C (−35 °F; 236 K)
Autoignition; temperature	747 °C (1,377 °F; 1,020 K)
Explosive limits	2.3–36%
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	660 mg/kg (guinea pig, oral); 380 mg/kg (rat, oral); 440 mg/kg (mouse, oral); 1140 mg/kg (rat, oral); 690 mg/kg (guinea pig, oral)
LC50 (median concentration)	1740 ppm (mouse, 4 h); 4000 ppm (rat, 4 h)
LCLo (lowest published)	2005 ppm (dog, 4 h); 4000 ppm (guinea pig, 4 h)
	NIOSH (US health exposure limits):
PEL (Permissible)	TWA 100 ppm (240 mg/m3)
REL (Recommended)	Ca
IDLH (Immediate danger)	Ca [400 ppm]
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Propylene oxide is an epoxide with the molecular formula C₃H₆O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols for use in making polyurethane plastics. It is a chiral epoxide, although it is commonly used as a racemic mixture.

This compound is sometimes called 1,2-propylene oxide to distinguish it from its isomer 1,3-propylene oxide, better known as oxetane.