What Is It?

1,4-dioxane is an impurity that may be present in trace amounts in some cosmetics and personal care products. 1,4-dioxane itself is not used as an intentionally added ingredient, but can form as a by-product during the manufacturing process of certain ethoxylated ingredients used in cosmetics and personal care products, including cleansing materials (i.e., detergents), foaming agents, emulsifiers, and solvents. 

Can 1,4-dioxane be removed from ingredients used in cosmetic and personal care products?

Manufacturers make significant efforts to reduce the concentration of residual 1,4-dioxane, although small residual amounts of 1,4-dioxane are nearly unavoidable. Industry and FDA have been aware of this issue for many years; FDA has been monitoring levels since the late 1970s. 

Where else is 1,4-dioxane found?

1,4-dioxane is naturally found in trace amounts in food items including cooked chicken, shrimp, and tomatoes. It can also be formed at low levels in certain food additives approved by the FDA for use in frozen desserts like ice cream and sherbets. The FDA has also set limits for 1,4-dioxane in glycerides and polyglycerides for use in products such as dietary supplements.

Why is it used in cosmetics and personal care products?

Scientific Facts:

Although frequently confused because of spelling, “1,4-dioxane” is not the same thing as the highly toxic environmental contaminant “dioxin” which is produced from burning fuels such as wood, coal, and oil. The two are completely different and unrelated substances. Dioxin is not found in any cosmetics or personal care products.

Safety Information:

Is 1,4-dioxane in cosmetic products harmful? 

Concerns initially were raised in the 1970s, when studies at the National Cancer Institute found an association between1,4-dioxane and cancer in animals when 1,4-dioxane was administered at high levels in the animal feed. However, the levels in cosmetic products are far lower [several thousand times lower] than those found to be harmful in feeding studies and, for the most part, the types of products in which it is found are only in contact with the skin for a short time [i.e., rinse-off products].

The following safety information is excerpted from the U.S. Food and Drug Administration (FDA) website:

 “The FDA has not independently conducted a hazard identification and risk assessment concerning exposure to 1,4-dioxane as a contaminant in cosmetic products. However, two recent international scientific studies of trace contamination levels of 1,4-dioxane in cosmetics (by the International Cooperation on Cosmetics Regulations (ICCR, an international group of regulatory authorities from the United States, the European Union, Japan, Canada, and Brazil), and by the European Commission Scientific Committee on Consumer Safety (SCCS)), have examined this issue. The ICCR work group determined that all of the levels reported in the recent literature are within acceptable margins of exposure based on available safety assessments from Canada, Europe, and Japan [1].  In an independent risk assessment, SCCS concluded that 1,4-dioxane amounts in cosmetic products are considered safe for consumers at trace levels of ≤10 ppm [2].”

“The FDA periodically monitors the levels of 1,4-dioxane in cosmetics products and we have observed that changes made in the manufacturing process have resulted in a significant decline over time in the levels of this contaminant in these products.”

“The FDA also conducted skin absorption studies, which showed that 1,4-dioxane can penetrate animal and human skin when applied in certain preparations, such as lotions. However, further research by the FDA determined that 1,4-dioxane evaporates readily, further diminishing the already small amount available for skin absorption, even in products that remain on the skin for hours [3].”

More safety Information:

In 1988, 1,4-dioxane was added to the State of California’s list of chemicals known to cause cancer under the Proposition 65 regulations. As part of the Proposition 65 regulations, however, California has established levels at which the chemicals listed under Proposition 65 for carcinogenicity and reproductive toxicity would not be considered a risk to consumers. These “Safe Harbor” levels are set through a rigorous scientific process in which the potential hazard of a substance is assessed and the information is used to set a safe level. The safe level set for 1,4-dioxane is 30 micrograms/day. The trace levels of 1,4-dioxane that may be present in some cosmetics or personal care products are well below these safe limits.


3. Robert L. Bronaugh, “Percutaneous Absorption of Cosmetic Ingredients,” in Principles of Cosmetics for the Dermatologist, Philip Frost, M.D., and Steven Horwitz, M.D., Eds. St. Louis: The C.V. Mosby Company, 1982