Warning Required: Products Containing Alpha Hydroxy Acids
This article applies to cosmetic products containing alpha hydroxy acids which are sold in the United States.
Alpha hydroxy acids (AHAs) are a class of ingredients which are commonly used in exfoliants and skin peels for both professional and at-home use. The most commonly used AHAs are glycolic and lactic acids, along with their derivatives as various forms of glycolates and lactates. However there are other AHAs used, such as citric, tartaric, malic and mandelic acids.
The Cosmetic Ingredient Review Expert Panel reviewed the safety of glycolic and lactic acids and their derivatives in 1998.1 At that time, they found that AHAs were safe in cosmetic products at a concentration of 10% or less.2 The report also found that the products should be accompanied by directions for the daily use of skin protection. In 2017, the Cosmetic Ingredient Review Expert Panel reviewed the 1998 safety assessment and more recent information and confirmed the original safety assessment and recommendations.3
In 2005, the FDA has published a guidance document4 which specifies that due to the potential for photosensitivity, products containing AHAs should have a Sunburn Alert on products packaging:
Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin's sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.
The sunburn alert is recommended for products containing AHAs that are intended to be applied to parts of the body which are exposed to the sun, regardless of whether they are leave-on or rinse-off products. The sunburn alert is not required if the product contains a sunscreen.5
Unlike other required warning statements, the sunburn alter for products containing AHAs is not specified directly in the regulations. However, the statutes do state that a cosmetic is misbranded if its labeling is false or misleading6 and “misleading” can be based on a failure to provide material facts regarding results of normal or customary use of a product.7 In other words, if you fail to tell the customer something important about what might happen if they use the product, that would be misleading … and make the product misbranded (and therefore illegal to sell in the United States).
In the case of products containing AHAs, the FDA believes that the sunburn alert contains material facts applicable and failure to provide the sunburn alert would make the product misbranded.
See also Beta Hydroxy Acids
1 Andersen FA. Final Report On the Safety Assessment of Glycolic Acid, Ammonium, Calcium, Potassium, and Sodium Glycolates, Methyl, Ethyl, Propyl, and Butyl Glycolates, and Lactic Acid, Ammonium, Calcium, Potassium, Sodium, and Tea-Lactates, Methyl, Ethyl, Isopropyl, and Butyl Lactates, and Lauryl, Myristyl, and Cetyl Lactates. International Journal of Toxicology. 1998;17(1_suppl):1-241. doi:10.1177/109158189801700101
2 The safety levels for non-continuous, rinse off products for use in salons by professionals were higher.
3 Fiume MM. Alpha Hydroxy Acids. International Journal of Toxicology. 2017;36(5_suppl2):15S-21S. doi:10.1177/1091581817716656
4 FDA. Guidance for Industry: Labeling for Cosmetics Containing Alpha Hydroxy Acids
5 Note that a sunscreen is an OTC drug, and a product containing both AHAs and a sunscreen would also be an OTC drug and must be manufactured by an approved drug manufacturer in a registered and inspected drug manufacturing facility. 21 CFR 207 – Requirements for Foreign and Domestic Establishment Registration and Listing for Human Drugs
6 21 USC 362(a) – Misbranded Cosmetics
7 21 USC 321(n) – Definitions Generally
