Chapter 11: The supporting cast · Part 1: Polymers
Polyethylene glycol (PEG)
- Made from a hazardous chemical
- Contaminant risk
The worst fact: a small number of people are seriously allergic to it. A 2016 review found 37 reported cases since 1977, and patients "commonly present with a history of repeated, severe reactions to a range of unrelated products in hospital and at home", because PEG is in so many products and few doctors suspect it.
Why brands use it: it's a binder that holds dishwasher tablets together.
Take care if: you've been diagnosed with PEG allergy. Read medicine and cosmetic labels too. A 2005 cosmetic review said PEGs shouldn't be applied to damaged skin.
Comes from: ethylene oxide added to water in repeated steps. Australia classes ethylene oxide as "May cause genetic defects; May cause cancer". That doesn't mean it's in the product, but it's not a great starting point for something you clean with.
Myth check: "PEG is antifreeze": no. Antifreeze is ethylene glycol, a different chemical. The EU caps ethylene and diethylene glycol in food-grade PEG at 0.25% combined. And on the COVID vaccines, a later FDA and CDC study found PEG antibodies weren't the main cause of the rare allergic reactions.
Contaminants: 1,4-dioxane (Australia: "May cause cancer") and ethylene oxide, by-products of making it. EU food grade allows up to 10 mg/kg of 1,4-dioxane and 0.2 mg/kg of ethylene oxide. US FDA surveys found average 1,4-dioxane in finished cosmetic products fell from 50 ppm in 1981 to 19 ppm in 1997; in 2008, 80% had none detectable. They're unlikely in a well-made product, but it's a factor you can't see on the label.
Fair to say: PEGs have "extremely low acute and chronic toxicities" and "do not readily penetrate intact skin".
Correct as of November 2026. What the badges mean
Sources
- Safe Work Australia. Hazardous Chemical Information System (HCIS): classifications for calcium chloride, boric acid, borax, and for N-vinylpyrrolidone, vinyl acetate, ethylene oxide, 1,4-dioxane, hydrazine, aniline, p-toluidine, styrene, chloromethane, carbon monoxide and octamethylcyclotetrasiloxane (D4).
- European Union. Regulation (EC) 1333/2008 Annex V; Regulation (EU) 231/2012 (food additive specifications); Regulation (EU) 2022/63 (E171); Regulation (EU) 1297/2014 (detergent capsules); Regulation (EC) 790/2009 and Delegated Regulation (EU) 2021/849 (borates); Regulation (EU) 109/2012; Regulation (EU) 2023/2055 (microplastics); Regulation (EU) 2024/1328 (D4, D5, D6); Regulation (EC) 1223/2009 (cosmetics) Annexes III and IV.
- Danish EPA. Substances in household detergents (2019).
- Cosmetic Ingredient Review: castor oil and hydrogenated castor oil (2007); styrene/acrylates copolymers (2014); glycol stearate (2023); microbial gums; galactomannans; PEGs (2005).
- Wenande E, Garvey LH. Immediate-type hypersensitivity to polyethylene glycols: a review. Clin Exp Allergy 2016.
The full source list is at the end of Chapter 11.