Propylene glycol

Propylene glycol (CAS 57-55-6), commonly abbreviated as PG and approved as E1520 in food applications, is a synthetic diol used across food, pharmaceutical, personal care, and industrial sectors.

Where is Propylene glycol used?

• Food and beverage: carrier for flavors, colors, and preservatives where water or oil-based solvents are unsuitable
• Pharmaceutical: solvent and co-solvent in oral liquids, topical creams, and injectable preparations
• Personal care: moisture control in lotions, serums, and hair care products
• Unsaturated polyester resin: reactive diol in the polymer backbone
• It functions as a humectant, solvent, and carrier.
• Used as an ingredient in cosmetics at concentrations less than 0.1% to greater than 50%.
• Used in hand sanitizers, antibacterial lotions, and saline solution.

Good to know: USP and FCC grades are the most commonly specified by procurement teams sourcing for highly regulated global end markets.

Formulation notes

• Used as artificial tears in ophthalmology at a low concentration of 0.6%.

Typical specification

• Assay is not less than 99.5%.
• Heavy metals content is 5 ppm maximum.
• Limit of ethylene glycol is not more than 0.10%.
• Water content is not more than 0.2%.
• Color is 10 APHA maximum.

Regulatory status

• Propylene glycol (1,2-propanediol) has an ADI of 0-25 mg/kg body weight established in 1973 by JECFA.
• Assigned INS number 1520 as a food additive.
• Propylene glycol USP is approved as food additive E1520 with a maximum limit of 1 g per kg in human food.

Frequently asked questions about Propylene glycol

Is propylene glycol marketed as a racemic mixture?

Propylene glycol is marketed as a racemic mixture unless otherwise specified.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.