In cosmetics, 1,4-dioxane is the byproduct of a chemical process used to soften harsh ingredients. Although the U.S. Food and Drug Administration says the levels of 1,4-dioxane found in cosmetics do not pose a hazard to consumers, the National Toxicology Agency says its presence—even as a trace contaminant—is cause for concern, and the Environmental Protection Agency lists it as a probable human carcinogen. Research from the Environmental Working Group revealed 1,4-dioxane in many children’s bath products. To steer clear of the toxin, avoid products including ingredients with "myreth," "oleth," "laureth," "ceteareth," any other "eth," "PEG," "polyethylene," "polyethylene glycol," "polyoxyethylene," or "oxynol."

Check out our Natural Food Merchandiser's personal care guide for more lingo you should know.