Smarter Living: Chemical Index

1,4-dioxane is a hazardous chemical sometimes found in shampoos, cosmetics, and other household products.

Health Concerns

Studies in laboratory animals indicate that 1,4-dioxane may cause cancer and the Environmental Protection Agency considers 1,4-dioxane to be a probable human carcinogen. Other health effects include kidney and liver toxicity if exposure occurs over long periods of time.


1,4-dioxane may occur as a chemical contaminant in consumer products that contain any of the following ingredients: PEG, polyethylene, polyethylene glycol, polyoxyethylene, compounds ending in –eth, and compounds ending in –oxynol. Sodium laureth sulfate is a common sudsing ingredient that can be contaminated with 1,4-dioxane.

1,4-dioxane has also been found in groundwater sites across the United States and may enter drinking supplies, but no Federal drinking water standards have been established for the chemical. Some state governments and EPA regions have set action levels.

When inhaled during showering and bathing, the chemical is rapidly absorbed into the body. It can also be absorbed if by swallowing. Although 1,4-dioxane can be absorbed through the skin, this route is less effective than the inhalation and oral routes.

An analysis by the Environmental Working Group suggests that 1,4-dioxane may be found in 22 percent of the more than 25,000 products in the Skin Deep database of cosmetics products. The analysis found that 57 percent of baby soaps contain the contaminant.

Stay Safe

Avoid consumer products containing the ingredients listed above that are likely to be contaminated with 1,4 dioxane. The chemical itself is unlikely to be listed on the label.

Organic standards do not permit the use of the chemical processes that lead to 1,4-dioxane contamination. Products bearing the USDA organic label are unlikely to contain this contaminant. However the use of the word "organic" in consumer care products is notoriously lax. Be sure to check for the USDA seal as a signal that the product has been manufactured without 1,4-dioxane contamination.

Learn More

Agency for Toxic Substances and Disease Registry (ATSDR). Public health statement for 1, 4 dioxane.

last revised 12/27/2011

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