Widely used in conditioners, moisturizers, deodorants, etc. Can be contaminated with 1,4-dioxane, which can cause cancer.
PEGs (polyethylene glycols) are petroleum-based compounds that are widely used in cosmetics as thickeners, solvents, softeners, and moisture-carriers. PEGs are commonly used as cosmetic cream bases. They are also used in pharmaceuticals as laxatives.
Health and Environmental Hazards
Depending on manufacturing processes, PEGs can be contaminated with measurable amounts of ethylene oxide and 1,4-dioxane. The International Agency for Research on Cancer classifies ethylene oxide as a known human carcinogen and 1,4-dioxane as a possible human carcinogen. Ethylene oxide can also harm the nervous system and the California Environmental Protection Agency has classified it as a developmental toxicant based on evidence that it may interfere with human development. 1,4-dioxane is also persistent. In other words, it doesn’t easily degrade and can remain in the environment long after it is rinsed down the shower drain. 1,4-dioxane can be removed from cosmetics during the manufacturing process by vacuum stripping, but there is no easy way for consumers to know whether products containing PEGs have undergone this process. In a study of personal care products marketed as “natural” or “organic” (uncertified), U.S. researchers found 1,4-dioxane as a contaminant in 46 of 100 products analyzed.
While carcinogenic contaminants are the primary concern, PEG compounds themselves show some evidence of genotoxicity and if used on broken skin can cause irritation and systemic toxicity. The industry panel that reviews the safety of cosmetics ingredients concluded that some PEG compounds are not safe for use on damaged skin (although the assessment generally approved of the use of these chemicals in cosmetics). Also, PEG functions as a “penetration enhancer,” increasing the permeability of the skin to allow greater absorption of the product — including harmful ingredients.
There are no restrictions on the use of parabens in cosmetics in Canada. Ethylene oxide and 1,4-dioxane are prohibited on Health Canada’s Cosmetic Ingredient Hotlist. However, when these chemicals are present in a product as a contaminant (i.e., an unintentional ingredient), the Hotlist restriction does not apply. 1,4-dioxane was recently assessed under the government’s Chemicals Management Plan, but Health Canada and Environment Canada concluded that the chemical did not meet the legal definition of “toxic” because estimated exposure levels were considered to be lower than those that might constitute a danger to human health. The assessment noted uncertainty in the exposure estimates, “due to the limited information on the presence or concentrations of the substance in consumer products available in Canada.”
Propylene glycol is a related chemical that, like PEGs, functions as a penetration enhancer and can allow harmful ingredients to be absorbed more readily through the skin. It can also cause allergic reactions. Health Canada categorized propylene glycol as a “moderate human health priority” and flagged it future assessment under the government’s Chemicals Management Plan. Other ethoxylates may be contaminated with ethylene oxide and 1,4-dioxane. These ingredients usually have chemical names including the letters “eth” (e.g., polyethylene glycol).