PEG is the contracted name for polyethylene glycol-7 glyceryl cocoate, and it’s derived from coconut acid and polyethylene glycol. It’s a non-ionic surfactant that functions as an emollient as well as a moisturizing, emulsifying, conditioning, and thickening agent in personal care products. Its compatibility with other non-ionic surfactants as well as a wide range of cationic and anionic surfactants makes it a very useful candidate for inclusion in many personal care product formulations. One main concern with PEGs is that they facilitate the absorption of lead and other heavy metals into the body.

PEGs are polymers of ethylene oxide, and although ethylene oxide is used in the manufacture of many personal care products, it’s highly toxic even in small amounts. For this reason, it’s considered too unsafe for direct use as a household product. Ethylene oxide causes several cancers, including breast, liver and bone cancer, as well as lymphoid and brain tumors, mesothelioma, and leukemia. The International Agency for Research on Cancer, the American Conference of Governmental Industrial Hygienists, and the German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area classify ethylene oxide as a cancer-causing (carcinogenic) chemical.

Ethylene oxide inhalation can be highly toxic. Continuous inhalation can produce carcinogenic effects and many health problems including dizziness, convulsions, seizures, comas, reproductive defects, neurological disorders, nausea, vomiting, headaches, irritation of the respiratory tract, memory loss, risk of cataract formation, as well as damage to the lungs, bronchi, and trachea. Skin exposure can lead to frost bite, irritation and dermatitis. Long-term exposure, either through inhalation or ingestion, can be fatal.

Note that products containing PEG and other chemicals that have been ethoxylated, or treated with ethylene oxide, induce cancer due to contamination by 1,4-dioxane, a carcinogen that’s produced when two molecules of ethylene glycol react (see ammonium laureth sulfate, polysorbates, steareths, and sodium laureth sulfate for more information about ethoxylation).