What Is Propylene Glycol

Propylene glycol has several different chemical varieties.

Propylene glycol (PG) is a colorless and odorless liquid chemical used for decades in a wide array of applications. It is considered non-toxic in small amounts by the U.S. Food and Drug Administration (FDA), however, large doses can cause seizures in humans and kidney and liver damage in animals.

Food Additives

In foods, PG absorbs water and maintains moisture. It dissolves food dyes and flavorings in drinks, and it keeps foods from freezing, such as in breweries and dairies. In food, it would be difficult to consume a dangerous dose, but babies, infants, the elderly and those with certain allergies may be more sensitive to the chemical.

Cosmetics

In cosmetics, PG is commonly used to emulsify oil components to water-based components. They also help cosmetic items keep from melting in high heat and freezing in low temperatures. The small amounts used in cosmetics do not pose health risks, except to those with sensitivities.

Pharmaceuticals

In medicines, PG acts as an emulsifier, specifically in topical agents and injectable medicines. It also acts as an excipient, or solvent, for the active ingredients in medications. Newborns have shown adverse reactions to medicines using this chemical.

Industrial Uses

Propylene glycol has a myriad of functions in industrial applications. The textile industry uses it as an intermediary in the production of polyester fiber. The military uses it to form smoke screens for troops. Military and commercial airlines use it as a de-icer for planes, however, ethylene glycol is also used because of its lower cost. PG can be found in liquid detergents, as well as a number of other uses.

References

• Agency for Toxic Substances & Disease Registry: Toxic Substances-Propylene Glycol
• Dow: Propylene Glycol
• Inchem: Propylene Glycol (PIM 443)
• Agency for Toxic Substances & Disease Registry: Ethylene Glycol and Propylene Glycol Toxicity: What is Propylene Glycol?
• American Academy of Pediatrics: "Inactive" Ingredients in Pharmaceutical Products: Update
• Cosmetics Info: Propylene Glycol

Resources

• Plastic Process Equipment: Propylene Glycol Industrial MSDS