February 2007

An EWG analysis of government and industry sources shows that at least 146 cosmetic ingredients may contain harmful impurities linked to cancer and other serious health impacts, including 3 of the top 20 most commonly used cosmetic ingredients. Our analysis of ingredients in 7,500 personal care products shows that because some of these ingredients are used so widely, the vast majority of products on the market have the potential to be contaminated with impurities. None of these impurities is regulated by the federal government.

“Indeed, it has been demonstrated that nitrosamines are carcinogenic in more animal species than any other category of chemical carcinogen. … Clearly, it appears that [nitrosamines] can be formed during storage, once a product has been opened.”

— U.K. Department of Trade and Industry, Cosmetic contamination study (DTI 1998)

An EWG analysis of government and industry sources (CIR 2003, FDA 2000a,b, UNECE 2004) shows that at least 146 cosmetic ingredients may contain harmful impurities linked to cancer and other serious health impacts (Tables 1 and 2), including 3 of the top 20 most commonly used cosmetic ingredients (Table 3). Our analysis of ingredients in 7,500 personal care products shows that because some of these ingredients are used so widely, the vast majority of products on the market have the potential to be contaminated with impurities. None of these impurities is regulated by the federal government:

  • Eighty percent of all products assessed contain ingredients that can be contaminated with impurities linked to cancer and other health problems, including more than 80 percent of all lip balms and baby bath products (Table 1).
  • Many common impurities readily absorb through the skin. FDA notes that the carcinogenic cosmetic impurity acrylamide is “rapidly absorbed through the skin” (FDA 2004a); that dioxane, a potential impurity in a wide range of ethoxylated cosmetic ingredients, “readily penetrates animal and human skin” (FDA 2000); and that the common family of impurities called nitrosamines also “penetrate the skin” (FDA 2000a).

Sources and prevalence of impurities. Unwanted impurities in cosmetic products can be manufacturing residuals, breakdown products from cosmetic ingredients, environmental contaminants in the case of plant-derived ingredients, or what are called “unreacted monomers,” the small building blocks of the large polymer ingredients common in cosmetics. Potential health harms associated with impurities can dwarf those linked to the product ingredients themselves, but are mitigated by the typically low levels of impurities in the products.

In their cosmetic ingredient review summaries, the industry safety panel notes concerns over potential impurities for about one of every 10 ingredients assessed. Likewise, in 10 percent of cases for which the panel has recommended concentration limits for chemicals in cosmetics, the limits have been set for impurities, not for the ingredient under review (CIR 2003). Of the four product concerns for which FDA explicitly requests direct contact from imported cosmetic inspectors, three are related to harmful impurities in the products (FDA 2000b).

In a 1998 personal care product testing program, a European government agency found carcinogenic impurities in 43 percent of 128 products tested (DTI 1998), including baby lotion and shampoo, sunscreen, and liquid soap. This study, focused on the family of carcinogenic chemicals called N-nitrosamines, joins other government and industry studies showing that harmful impurities can commonly contaminate cosmetic products (see, for example, CIR 2003 and FDA 2000a,b).

Government and industry sources reveal 24 industrial chemicals or groups of chemicals identified as potential impurities in a wide range of products, with health concerns spanning cancer, neurotoxicity, and reproductive problems (CIR 2003, FDA 2000a,b, UNECE 2004). The certainty of these impurities’ presence in cosmetics ranges widely, from speculation — reflected in the industry safety panel setting limits on residues of arsenic, mercury, PCBs and pesticides in cottonseed acid, for example — to complete confirmation, such as the established presence of carcinogenic nitrosamines in a wide range of personal care products.

Cosmetic industry polices the purity of its own products. Some manufacturers buy ingredients certified by an independent organization called United States Pharmacopeia (USP). These ingredients may contain lower levels of harmful impurities, but the criteria for certification are not public. There are no federal standards for ingredient purity. While is seems likely that some companies purchase or manufacture refined, purified ingredients, it is equally likely that many do not. Consumers and government health officials have no way to know.

Because the purity of cosmetic ingredients is not regulated by federal law, product purity has become a business decision. Companies can weigh the cost of purchasing purified or certified ingredients against the potential liability of selling products that may contain carcinogenic impurities. Liabilities are low: cancer typically has a long latency period, and a doctor can rarely trace the disease back to particular exposures. Although some studies show evidence that actions taken by industry have reduced levels of some impurities over the past 25 years (Matyska et al. 2000), recent testing programs undertaken by FDA and European agencies show that the use of impure ingredients by the industry is still common (FDA 1996, DTI 1998).

It is clear from a review of ingredient assessment summaries published by the Cosmetic Ingredient Review that the industry panel routinely approves ingredients in the absence of impurity data. In a review of a large class of surfactants called ceteareths, for example, the panel stressed “the importance of purification procedures to remove… impurities” noting that “…in the absence of impurities data, the Panel caution[s] that a Ceteareth preparation should not contain 1,4-dioxane or ethylene oxide which are possible oxidation products” (CIR 2003). In another case the panel assumed industry would limit levels of acrylic acid and methacrylic acid impurities in acrylate polymer ingredients after learning that the impurities have an unpleasant odor, an incentive for industry to keep levels low (CIR 2003).

Two of the impurities commonly found in cosmetic ingredients are discussed below.

1,4-dioxane. The Environmental Protection Agency considers 1,4-dioxane a probable human carcinogen, based of the “induction of nasal cavity and liver carcinomas in multiple strains of rats, liver carcinomas in mice, and gall bladder carcinomas in guinea pigs” (EPA, 2003). In a review conducted in 1982, the Cosmetic Ingredient Review panel noted that the cosmetic industry was aware of the problem of the presence of the 1,4-dioxane in cosmetics and was making an effort to lower or remove 1,4-dioxane in cosmetics (CIR 2003, review of choleth-24). But 18 years later, FDA expressed continuing concerns about 1,4-dioxane, noting its potential to contaminate a wide range of products, its ready penetration through the skin, and the evidence linking it to systemic cancer in a skin painting study (FDA 2000). FDA notes that 1,4-dioxane can be removed “by means of vacuum stripping at the end of the polymerization process without an unreasonable increase in raw material cost” (FDA 2000), but such treatment would be voluntary on the part of industry.

A consumer could identify products with potential 1,4-dioxane contamination by scanning product labels for the common ethoxylated surfactants that may contain the impurity, which according to FDA are identifiable by the prefix, or by the designations, of ‘PEG,’ ‘Polyethylene,’ ‘Polyethylene glycol’ ‘Polyoxyethylene,’ ‘–eth–,’ or ‘–oxynol–’ (FDA, 2000).

Nitrosamines. FDA began analyzing personal care products for the carcinogenic impurities known as nitrosamines as early as 1979. In tests of 300 products between 1979 and 1980 the agency identified a nitrosamine called N-nitrosoethanolamine (NDELA) at levels up to 150 parts per million (ppm). The agency published a notice in the Federal Register of April 10, 1979 (44 FR 21365) warning the cosmetics industry that products containing nitrosamines may be considered adulterated and subject to enforcement action. In a testing program 12 years later, the agency found that maximum levels had dropped 50-fold, to three ppm (Matyksa et al. 2000). And in a European agency study published in 1998, maximum levels of total N-nitroso compounds, including NDELA and related chemicals, had fallen to less than one ppm (DTI 1998).

Despite the apparent reduction in nitrosamine levels achieved by industry over the past quarter century, FDA remains concerned about nitrosamine impurities, because of the solid evidence linking these chemicals to cancer, and because of their ready absorption through the skin:

“FDA has urged cosmetic manufacturers to voluntarily remove from cosmetics any ingredient which may combine with others to form NDELA and to conduct additional testing to determine why cosmetics become contaminated with NDELA.”

— USFDA Office of Cosmetics and Colors, 1996

According to scientists from San Jose University, the common nitrosamine impurity NDELA “is readily absorbed through the skin and accumulates in organs, such as the liver, bladder, etc. where it induces chronic toxic effects” (Matyska et al. 2000). The International Agency for Research on Carcinogens has found that nitrosamines are carcinogenic in all animal species studied, including primates. No other carcinogen has been found to be carcinogenic in as many species as nitrosamines. (IARC, 1978; 1982; 1985; 1987).

It may be the case that industry has developed methods to lower nitrosamine levels in newly-manufactured products, but recent studies suggest that industry’s persistence in using nitrosamine precursors in a wide range of products guarantees that the products will become contamined with nitrosamines during a period of normal use, as the precursors react with other chemicals to form nitrosamines. Our analysis shows that one of every 10 products on the market contains ingredients that can combine with other chemicals to form nitrosamines. Notably, a study sponsed by the U.K. Department of Trade and Industry found that nitrosamine levels in some products had more than doubled four months after the product was opened, and increased by more than four-fold over 17 months (DTI 1998).

Table 1. Products that may be contaminated with impurities.

9,747 (76.8%) products may be contaminated with impurities.
Showing top 20 product categories, ranked by prevalence.

Category Percent of Products
Varicose/Spider Vein Treatment 100.0% (9)
Hair Color and Bleaching 98.1% (156)
Bubble Bath 97.4% (74)
Shaving Cream 96.2% (51)
Shampoo 96.2% (607)
Baby Wipes 95.0% (19)
Depilatory 94.3% (50)
Baby Sunscreen 93.8% (15)
Baby Shampoo 92.6% (25)
Mascara 92.5% (196)
Body Wash/Cleanser 91.8% (515)
Liquid Hand Soap 91.0% (81)
Baby Lotion 90.9% (30)
Sunless Tanning 90.5% (95)
Hair Spray 90.1% (127)
Hand Sanitizer 90.0% (9)
After Sun Product 89.7% (26)
Anti-aging 89.1% (197)
Moisturizer 88.4% (1047)
Sunscreen/Tanning Oil 87.4% (250)


Table 3. Top 20 ingredients with impurity concerns, by prevalence of use.

Ingredient Impurity Concern(s) Percent of Products



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