Food Grade Propylene Glycol

Propylene glycol is a viscous and clear organic alcohol with a faint, sweet taste. It is commonly used in cosmetics, food, and toiletries including perfume formulations. Its official IUPAC name is propane-1,2-diol, although it is also known in the market by several names like 1,2-dihydroxypropane, methylethylene glycol, Sirlene, and Dowfrost.

Because of its unique properties, it serves as a:

solvent
emulsifier
drug excipient
stabilizer
heat transfer fluid

Physical Properties:

Molecular mass: 76.10 g/mol
Melting point: -59簞 C
Boiling point: 187.6簞 C
Vapor pressure: 0.2 (23簞 C)
Vapor density: 2.62 (air=1)
Viscosity: 91.41 cp (10.45簞 C)
Surface tension: 40.1 g/s2 (25簞 C)
Refractive index: 1.4324 (20簞 C)
Heat of vaporization: 66.27 kJ/mol
Heat of combustion: -1828 kJ/mol

Production:

In the traditional process, propylene oxide is subjected to hydrolysis at a temperature of 200簞C and 12 bar pressure. It will then yield a mixture of different glycols which is dehydrated to separate the different grades and distilled before storage and distribution. There is also a lot of interest in producing propylene glycol from renewable sources like glycerin. But regardless of the process, production is strictly monitored and controlled through a track-and-trace system from the raw material up to delivery. These stringent standards are employed to ensure safety and quality.

Safety:

Propylene glycol has been used for more than half a century in health-sensitive applications like drugs, food, and cosmetics. Research has proven that its toxicity is very low and it is rapidly converted into lactic acid upon application to the body. It does not even harm the environment as it is readily biodegradable. Propylene glycol is included in the list of generally regarded as safe (GRAS) food additives by the US Food and Drug Agency (FDA).

Applications:

Cosmetics and toiletries

Propylene glycol USP is usually added as a stabilizer and moisturizer for different cosmetic formulations. It provides texture for lipsticks, stabilizes oil-in-water lotions, provides foams for shampoos, and serves as a perfume fixative. Other toiletry uses include:

Skin care: body lotions, sunscreen creams

Hair care: shampoos, conditioners, gels

Personal care: shower gels, facial toners, shaving creams, antiperspirants

Infant care: diaper wipes, antiseptics

Oral care: toothpastes, mouthwashes

Food

It is also a convenient carrier for flavor and color because of its neutral quality. Propylene glycol functions without altering the qualities of other food ingredients. It attracts water, is edible, and is safe. As a food additive, it is marketed as E 1520. Its uses for food and drugs include:

Thickener, clarifier, and stabilizer for beers, salad dressings, and dairy products

Solvent for cakes, biscuits, pastries, and juices

Excipient for therapeutic drugs, local anesthetics, vitamins, hormones, and antiseptics