Review Finds Modest Risk From Children's Toiletries
Saturday, March 14, 2009
Extensive studies of two toxic chemicals found in children's bath and personal care products suggest that if they pose a health hazard, it is likely to be extremely small and probably incalculable, a review of scientific research shows.
The two chemical compounds -- 1,4-dioxane and formaldehyde -- were found in trace quantities in children's shampoos, bath gels, lotions and wipes in a study conducted by the consumer group Campaign for Safe Cosmetics.
The results, released this week, showed that of the 48 products studied, two-thirds contained 1,4-dioxane. A subgroup of 28 products was tested for formaldehyde, and about 80 percent contained that compound. Numerous compounds contained both.
Neither of the compounds is listed as an ingredient in the products. Formaldehyde is a breakdown product of preservatives in the liquids, and 1,4-dioxane is a trace contaminant left from the manufacturing process.
But federal experts yesterday urged caution in assessing the results of the study.
The Environmental Protection Agency, which evaluates the toxicity of chemical compounds, released a statement yesterday saying that it "is currently doing new human health risk assessments on both dioxane and formaldehyde."
It noted that previous studies had shown dioxane may cause cancer when inhaled, and formaldehyde may cause cancer when ingested, but that the agency has "not yet reached a determination pertaining to skin exposure."
Because the products are washed off, the ability of the body to absorb them is limited. The low-dose, short-lived and intermittent nature of exposure is one of the reasons the Food and Drug Administration does not require that the chemicals be removed.
"FDA has not concluded, based on risk assessment, that the products containing these substances are injurious under intended conditions of use," said Linda M. Katz, director of FDA's office of cosmetics and colors.
The human health effects of formaldehyde have been studied extensively; those of 1,4-dioxane, less so. (The second compound is not the same as dioxin, a much-studied industrial contaminant.) In virtually all cases, however, researchers have examined the experience of people exposed frequently and for long periods (often decades) to much higher doses of the chemicals than a bathing child would get.
Dioxane, which evaporates quickly, carries a label as a "probable human carcinogen" based on animal studies. Rats and mice fed relatively large amounts of it in drinking water for most of their lives were at higher risk for cancer of the nasal cavity and liver than animals not exposed to the chemical.
Three epidemiological studies of workers exposed to 1,4-dioxane on the job, however, found no increase in cancer deaths, according to an EPA assessment.
At the Society of Toxicology's annual meeting, which will be held in Baltimore next week, a CDC scientist is scheduled to present a study in which blood levels of 1,4-dioxane were measured in about 2,000 Americans 12 and older. No detectable amounts were found. That suggests actual -- as opposed to theoretical -- exposure to the compound is virtually nil.
Formaldehyde can cause two kinds of skin problems: allergic reactions in people sensitive to it; and garden-variety irritation in people chronically exposed, such as embalmers.
Studies suggest that 1 to 4 percent of the population is allergic to formaldehyde. However, allergic reactions are rare when the concentration is less than .025 percent, which is the equivalent of 250 parts per million. Thirteen out of the 23 products found to contain formaldehyde in the Campaign for Safe Cosmetics survey had levels over 250 parts per million (with the highest being 610).
There are no studies of mortality from skin exposure to formaldehyde. However, mice exposed repeatedly to 10 percent concentrations of the chemical did not have shorter lives than other mice.
Formaldehyde is also a "probable human carcinogen" in the EPA's eyes.
Lab animals chronically inhaling the compound have higher rates of cancer of the nasal passages. More than 40 human studies of occupational exposure -- in pathologists, funeral directors, garment workers, resin-makers -- overall demonstrate a slight increase in cancer of the lungs and the nose and throat.