Propylene glycol

Propylene glycol^[1]
Names
	Preferred IUPAC name Propane-1,2-diol
	Other names Propylene glycol; α-Propylene glycol; 1,2-Propanediol; 1,2-Dihydroxypropane; Methyl ethyl glycol; Methylethylene glycol;
Identifiers
CAS Number	57-55-6 racemic ; 4254-15-3 S-enantiomer;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:16997 ;
ChEMBL	ChEMBL286398 ;
ChemSpider	13835224 ;
ECHA InfoCard	100.000.307
EC Number	200-338-0;
E number	E1520 (additional chemicals)
KEGG	C00583;
PubChem CID	1030;
RTECS number	TY6300000;
UNII	6DC9Q167V3 ; 942194N4TD (S-enantiomer) ;
CompTox Dashboard (EPA)	DTXSID0021206 ;
	InChI InChI=1S/C3H8O2/c1-3(5)2-4/h3-5H,2H2,1H3 Key: DNIAPMSPPWPWGF-UHFFFAOYSA-N ;
	SMILES CC(O)CO;
Properties
Chemical formula	C3H8O2
Molar mass	76.095 g·mol−1
Appearance	colourless liquid
Odor	odorless
Density	1.036 g/cm3
Melting point	−59 °C (−74 °F; 214 K)
Boiling point	188.2 °C (370.8 °F; 461.3 K)
Solubility in water	Miscible
Solubility in ethanol	Miscible
Solubility in diethyl ether	Miscible
Solubility in acetone	Miscible
Solubility in chloroform	Miscible
log P	−1.34
Vapor pressure	10.66 Pa (20 °C)
Thermal conductivity	0.34 W/m·K (50% H2O @ 90 °C (194 °F))
Viscosity	0.042 Pa·s
Thermochemistry
Heat capacity (C)	189.9 J/(mol·K)
Pharmacology
ATCvet code	QA16QA01 (WHO)
Hazards
NFPA 704 (fire diamond)	0 1 0
Related compounds
Related glycols	Ethylene glycol, 1,3-propanediol
	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 glycol (IUPAC name: propane-1,2-diol) is a viscous, colorless liquid. It is almost odorless and has a faintly sweet taste. Its chemical formula is CH₃CH(OH)CH₂OH. As it contains two alcohol groups, it is classified as a diol. An aliphatic diol may also be called a glycol. It is miscible with a broad range of solvents, including water, acetone, and chloroform. In general, glycols^[6] are non-irritating and have very low volatility.^[7]

For certain uses as a food additive, propylene glycol is considered as GRAS by the US Food and Drug Administration, and is approved for food manufacturing.^[8] In the European Union, it has E-number E1520 for food applications. For cosmetics and pharmacology, the number is E490. Propylene glycol is also present in propylene glycol alginate, which is known as E405.

Propylene glycol is approved and used as a vehicle for topical, oral, and some intravenous pharmaceutical preparations in the US and Europe.

^ The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. Merck & Co. 1989. ISBN 978-0911910285.
^ "Propylene Glycol_msds".
^ Zaripov, Z.I. (1982). Experimental study of the isobaric heat capacity of liquid organic compounds with molecular weights of up to 4000 a.e.m.
^ GHS: "Kein gefährlicher Stoff nach GHS" GESTIS 013620
^ "Propylene Glycol - Cameo Chemicals". NOAA Office of Response and Restoration. NOAA. Retrieved 3 October 2018.
^ Zapka, Maskrey (2016). Hawaii Energy and Environmental Technologies (HEET) Initiative.
^ Sullivan, Carl J.; Kuenz, Anja; Vorlop, Klaus-Dieter (2018). "Propanediols". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_163.pub2. ISBN 978-3-527-30673-2.
^ "Propylene glycol, Subpart B - Listing of Specific Substances Affirmed as GRAS, Sec. 184.1666 (original 25 June 1982)". Title 21, Code of Federal Regulations, US Food and Drug Administration. 30 August 2024. Archived from the original on September 2, 2003. Retrieved 20 November 2024.

[1] The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals. Merck & Co. 1989. ISBN 978-0911910285.

[chemsrc-2] "Propylene Glycol_msds".

[3] Zaripov, Z.I. (1982). Experimental study of the isobaric heat capacity of liquid organic compounds with molecular weights of up to 4000 a.e.m.

[4] GHS: "Kein gefährlicher Stoff nach GHS" GESTIS 013620

[5] "Propylene Glycol - Cameo Chemicals". NOAA Office of Response and Restoration. NOAA. Retrieved 3 October 2018.

[6] Zapka, Maskrey (2016). Hawaii Energy and Environmental Technologies (HEET) Initiative.

[Ullmann-7] Sullivan, Carl J.; Kuenz, Anja; Vorlop, Klaus-Dieter (2018). "Propanediols". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_163.pub2. ISBN 978-3-527-30673-2.

[gras-8] "Propylene glycol, Subpart B - Listing of Specific Substances Affirmed as GRAS, Sec. 184.1666 (original 25 June 1982)". Title 21, Code of Federal Regulations, US Food and Drug Administration. 30 August 2024. Archived from the original on September 2, 2003. Retrieved 20 November 2024.

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