AHA Safety – Sun Sensitivity

An additional concern arose as FDA prepared its 1996 report on AHA safety: Some people who had reported adverse reactions cited increased sun sensitivity. In addition, one industry-sponsored study found that participants whose skin was exposed to 4 percent glycolic acid twice daily for 12 weeks developed minimal skin redness with 13 percent less ultraviolet (UV) radiation exposure than normal. Three participants developed minimal redness with 50 percent less UV exposure than normal.

Another study that looked at the effects of glycolic acid on production of sunburn cells (markers for UV-induced skin damage) found that people who received the AHA product in the presence of UV radiation experienced twice the cell damage in areas where the AHA had been applied than those who were treated with the non-AHA product.

FDA’s concern is that people who are sensitive to sunlight may be particularly susceptible to UV rays, which can damage the skin and, over a long period, can cause skin cancer.

In 1997, the Cosmetic Ingredient Review Panel–the cosmetic industry’s self-regulatory body for reviewing and addressing safety of cosmetic ingredients–concluded that the AHA’s glycolic acid and lactic acid and their related chemical compounds are safe for use in products intended for consumer use when:

• the AHA concentration is 10 percent or less
• the final product has a pH of 3.5 or greater (lower numbers indicate greater acidity)
• the final product is formulated in such a way that it protects the skin from increased sun sensitivity or its package directions tell consumers to use sunscreen products.

For AHA products used by trained cosmetologists, the Cosmetic Ingredient Review Panel concluded that formulations of glycolic acid and lactic acid at concentrations of 30 percent or less and a pH of 3.0 or greater intended for only “brief” use at one time followed by thorough rinsing and daily use of sun protection are safe.

The panel’s conclusions actually serve as guidelines for cosmetic manufacturers, Bailey says. “This means that each manufacturer of an AHA product should conduct appropriate testing on their products to measure whether or not the product increases the sensitivity of the user to UV radiation and, if so, should add sun protection to their product and warn consumers to take extra steps to protect themselves at all times.”

Meanwhile, FDA continues to study AHA safety. Later this year, scientists with the National Toxicology Program and FDA will use hairless mice to study the effect of AHAs on the risk of cancer associated with sunlight and UV radiation. The study will run for about three years.

Depending on the outcome of FDA’s investigation, Bailey says, the agency may or may not take action against AHA products. “The absence of action by FDA to date doesn’t mean that there won’t be any in the future.”

Source: U. S. Food and Drug Administration