Are PEGs safe for use in Cosmetics?

What are PEG's?
PEG is an acronym for polyethylene glycol. There are various forms, identified by the number that follows PEG e.g. PEG-100. Not very sexy, they are multi-purpose in cosmetics. They are used as emollients to soften and lubricate skin, or as emulsifiers which help mix/combine water based ingredients with oil based ingredients, thickeners, binding agents and they can help active ingredients penetrate into the skin.
Are PEG's safe?
YES, according to the final conclusions of the 2005 Toxicology and Preclinical Affairs report:
"The PEGs produce little or no ocular or dermal irritation and have extremely low acute and chronic toxicities. They do not readily penetrate intact skin, and in view of the wide use of preparations containing PEGs, only a few case reports on sensitization reactions have been published, mostly involving patients with exposure to PEGs in meds, or following exposure to injured or chronically inflamed skin. On healthy skin, the sensitizing potential of these compounds appear to be negative.”
Why are PEG's controversial?
They are questioned because they are made synthetically using Ethylene Oxide (EO), which is a chemical (gas) from the petroleum industry, to synthesise it. Now it is true that EO is a dangerous substance alone, but so is caustic soda. However, nothing remains of the EO gas within the PEG and the concern that they can carry nasty chemicals into the body is unfounded. Hence they can be used safely in cosmetics. In fact PEGs used in cosmetics are globally approved including in California (which says a lot!). The additional question mark is the sourcing of this ingredient - whether it is sustainable or not.
The talibans of "natural" (not my description), hate it because EO is "petrochemistry" and thus not "natural". A French company once made EO from sugar cane and used it to manufacture "natural" Laureth sulfate. It even got an Ecocertificate, but was not a commercial success and was abandoned.
Unfortunately, though, with all the negative buzz and noise around PEGs, some consumers look on the labels and refuse to buy things with PEG in the INCI list. There is a little hypocrisy though as it is small brands who suffer most from the fear that has been created. While huge corporate, or celebrity brands seem to get away with anything, due to the sheer volume of customers who use their products. You only have to look at animal testing concerns in China. Corporate brands like MAC and and others, take a little flack for selling in China but it does not affect their UK sales materially. Same with PEGs. Small brands seem to be held to a higher (and in many cases unproven) standard.
This blog post has been written in collaboration with Chris Smith and Professor Karl Lintner.