What is Propylene glycol?
Propylene glycol (PG or MPG) is a colorless, odorless liquid is an FDA-approved additive commonly used in foods, cosmetics and pharmaceuticals. It is generally considered safe: it is water-soluble and does not irritate skin, though it might be mildly irritating to eyes, if it comes in contact with them. Numerous studies support that PG is not a skin sensitizer or a carcinogen.
How is it produced?
Propylene glycol is produced by a reaction of propylene oxide with water. For more than five decades propylene glycol has had an unsurpassed reputation for safe use in a wide range of consumer products, including many foodstuffs, animal feed, cosmetics such as soap and shampoo and medications, as well as industrial applications.
How does it work?
With its unique combination of properties propylene glycol fulfills various roles in different environments. It
serves as a solvent
connects and stabilizes insoluble fluids (emulsifier)
helps to bind and transport other substances (excipient)
holds and dissolves active ingredients equally in a medium
attracts/holds water/moisture (hygroscopic)
reduces the freezing point
increases the boiling point
offers outstanding stability with high flash and boiling points
The propylene glycol molecule is chemically neutral, i.e. it usually does not react with other substances. This is a particularly helpful property when seeking to combine contrasting chemical elements, for example in a perfume, to create a single, homogeneous fluid.
By emulsifying the active ingredients, which otherwise would not mix, the propylene glycol creates a stable homogeneous fluid that will allow the intended final product, be it a face cream or shampoo, for example, to do its job.
Is propylene glycol safe for babies and small children?
From over 50 years of safe use, and from existing studies, there is no indication that propylene glycol has any negative effects on the health of humans, including that of babies and small children.
Sources: www.dow.com and www.propylene-glycol.com