Propylene Glycol USP

Cas Number


Other Names

Propylene glycol

α-Propylene glycol



Methyl ethyl glycol (MEG)

Methylethylene glycol

The formula



Propylene glycol, also called propane-1,2-diol, is a synthetic organic compound. It is a viscous colorless liquid which is nearly odorless but possesses a faintly sweet taste. Chemically it is classed as a diol and is miscible with a broad range of solvents, including water, acetone and chloroform.

Physical and Chemical Properties
Physical state and appearance Colorless Liquid
Odor Odorless
Molecular Weight 76.09 g/mol
pH (1% soln/water): 6
Boiling Point 186 to 189°C
Flash point 104°C
Melting Point -59°C
Vapor Pressure: 0.011 k Pa
Vapor Density 2.6 [Air = 1]
Assay , wt % min 99.8
Sp. Gr. (25/25 ºc) 1.035 – 1.037
Colour, APHA max 10
Water, ppm max 700
Acidity, ppm as acetic acid max 30
Iron , ppm max 0.1
Chloride, wt . ppm max 1.0
Sulfate, wt . ppm max 10
Heavy metal, ppm max 5
Rsenic, wt . ppm max 1
Residue ppm max 20
Residue solvent pass
Gg wt . ppm max 50
Deg wt . ppm max 50
Distillation range (1 amt) ºc 186 – 189

Humectants due to their hygroscopic nature and ability to attract and hold water.

Preservatives due to inherent antimicrobial activity against a wide range of bacterial and fungal species.

Propylene glycols are commonly used in many types of cosmetic formulations such as skin care (creams, moisturizers, cleansers, lotions, sun care products).

Deodorants and antiperspirants (roll-on, stick and gel deodorants).

Hair care (shampoos, conditioners, wave sets, styling gels and coloring products).

Shaving products (creams, foams, gels, and after-shave lotions).

Bath and shower products, Perfumes and colognes, Baby care products (baby wipes), Hand cleansing and disinfecting gels, Color cosmetics (blushes, eyeliner, lipsticks, eye shadow), Dental care (mouth washes and toothpastes).