Very little about the process restricts their sale. And it’s a somewhat alarming idea to put acids on the skin. It raises obvious safety questions. — Dr. John Bailey, Director of FDA’s Office of Cosmetics and Color, on the use of alpha hydroxy acids (AHAs) in cosmetics (FDA 1999)

After four weeks of AHA application, volunteers’ sensitivity to skin reddening produced by UV increased by 18%. Similarly, the volunteers’ sensitivity to UV-induced cellular damage doubled, on average, with considerable differences among individuals. — FDA’s Office of Cosmetics and Color, on new AHA safety studies (FDA 2000b)

On May 21, 1992 FDA issued a consumer warning that commercial “skin peel” products, advertised to remove wrinkles, blemishes, blotches and acne scars, could destroy the upper layers of the skin, causing severe burns, swelling, and pain. FDA describes the following progression: “The skin initially reddens, as with a sunburn, then darkens and finally peels away revealing what manufacturers claim will be “new skin.” Treatments may be painful and leave permanent scars” (FDA 1992).

Since these initial warnings, the use of the active skin peel ingredients — alpha and beta hydroxy acids (AHAs and BHAs) — has grown dramatically in the cosmetic industry. According to EWG’s 2004 assessment of ingredient labels for 7,500 personal care products, these acids are now added to one of every 17 products on the market, including nearly 10 percent of all moisturizers and six percent of all sunscreens. The acids are commonly used in products promoted as enhancing the youthful appearance of skin.

Beginning with its initial burn warnings, FDA has now studied the safety of AHAs and BHAs for 14 years, driven in part by the increasing use of these acids in cosmetics, as well as by the agency’s estimate that AHAs and BHAs injure 1,000 people nationwide each year (FDA 1999). Most recently, FDA’s Office of Women’s Health sponsored studies that have linked these ingredients to UV-induced skin damage and potential increased risks of skin cancer. The studies identified a doubling of UV damage to skin among people using AHA-containing products (FDA 2000b).

According to the Environmental Protection Agency, skin cancer in the U.S. has reached “epidemic proportions,” with more than one million new cases occurring each year. At current rates one in five Americans is expected to develop skin cancer over their lifetime, and one American dies every hour from the disease (EPA 2004). The use of acids in cosmetics may be contributing to current skin cancer rates. The use of these acids in sunscreens, where they appear in six percent of all products we assessed, is perplexing and counterintuitive, and may detract from the cancer protection sunscreen products normally provide.

FDA’s 14-year review process has culminated with the Agency issuing guidance on the need for product manufacturers to include sunburn warnings on their products (FDA 2002). The guidance is was finalized in 2005, and is voluntary, highlighting the agency’s lack of meaningful authority over cosmetics, even on an issue that the Director of FDA’s Office of Cosmetics and Color found “alarming” (FDA 1999). The suggested warnings, a rare request from an agency that has in its history tackled only a few cosmetic safety issues in such depth, include language advising consumers to “Use a sunscreen and limit sun exposure while using this product and for a week afterwards” (FDA 2002).

The cosmetic industry’s efforts to preserve the use of these acids in products began with an industry-sponsored study that showed increased UV-induced skin damage for product testers. The cosmetic trade association CTFA presented this study to the industry’s safety panel in 1996. According to FDA, the panel approved the use of AHAs in cosmetics in June 1997 in spite of the study results and “in spite of serious safety questions submitted by a consumer group and a major manufacturer” (FDA 1997).

The industry panel found that AHAs are “safe for use in cosmetic products at concentrations less than or equal to 10 percent, at final formulation pHs greater than or equal to 3.5, when formulated to avoid increasing the skin’s sensitivity to the sun, or when directions for use include the daily use of sun protection.” For salon use, the panel found AHAs “safe for use at concentrations less than or equal to 30 percent, at final formulation pHs greater than or equal to 3.0, in products designed for brief, discontinuous use followed by thorough rinsing from the skin, when applied by trained professionals, and when application is accompanied by directions for the daily use of sun protection” (CIR 2003).

In their critique of industry panel recommendations, FDA implies that the safety panel’s admonition to industry is less than useful to consumers, since “AHA concentration and pH are generally not noted on all products. (FDA does not require it.)” The agency notes that consumers can request the information from the manufacturer (FDA 1997).

Comments on AHAs from FDA’s Director of the Office of Cosmetics and Color Dr. John Bailey, coming several years prior to the agency’s issuance of suggested, voluntary warning language for cosmetic manufacturers, illustrate the problem inherent in a regulatory system that does not require premarket safety testing: “There are many unanswered questions in front of us… AHAs are unlike anything else ever introduced onto the cosmetic market on such a wide scale. They are not your traditional cosmetics” (FDA 1999).


Cosmetics Ingredient Review (CIR) (2003). 2003 CIR Compendium, containing abstracts, discussions, and conclusions of CIR cosmetic ingredient safety assessments. Washington DC.

Environmental Protection Agency (EPA) (2004). Health effects of overexposure to the sun. Accessed online May 10 2004 at

Food and Drug Administration (FDA) (1992). Skin Peelers. HHS News. P92-13: May 21, 1992. Ohline May 26 2004 at

Food and Drug Administration (FDA) (1997). Alpha Hydroxy Acids in Cosmetics. FDA Backgrounder July 3 1997. Accessed online May 26 2004

Food and Drug Administration (FDA) (1999). Alpha hydroxy acids for skin care; Smooth sailing or rough seas? Office of Cosmetics and Color Fact Sheet. Revised May 1999. Accessed online May 10, 2004 at

Food and Drug Administration (FDA) (2000b). AHAs and UV sensitivity: Results of new FDA-sponsored studies. Office of Cosmetics and Color Fact Sheet. March 2, 2000. Accessed online May 10, 2004 at

Food and Drug Administration (FDA) (2002). Guidance for industry. Labeling for topically applied cosmetic products containing alpha hydroxyl acids as ingredients. FDA Center for Food Safety and Applied Nutrition. December 2, 2002. Accessed online May 10, 2004 at