What Is It?
Glycolic Acid and Lactic Acid are naturally occuring organic acids also known as Alpha Hydroxy Acids or AHAs. The salts of Glycolic Acid (Ammonium Glycolate, Sodium Glycolate), the salts of Lactic Acid (Ammonium Lactate, Calcium Lactate, Potassiu Lactate, Sodium Lactate, TEA-Lactate) and the esters of Lactic Acid (Methyl Lactate, Ethyl Lactate, Butyl Lactate, Lauryl Lactate, Myristyl Lactate, Cetyl Lactate) may also be used in cosmetics and personal care products. In cosmetics and personal care products, these ingredients are used in the formulation of moisturizers, cleansing products, and other skin care products, as well as in makeup, shampoos, hair dyes and colors and other hair care products.
Why is it used in cosmetics and personal care products?
The following functions have been reported for Glycolic Acid, Lactic Acid and their salts and esters.
- Buffering agent – Ammonium Lactate, Potassium Lactate, Sodium Lactate
- Cosmetic astringent – Calcium Lactate
- Exfoliant – Glycolic Acid, Lactic Acid, Ammonium Glycolate, Ammonium Lactate, Calcium Lactate, Potassium Lactate, Sodium Lactate
- Humectant – Lactic Acid
- pH adjuster – Glycolic Acid, Lactic Acid, Ammonium Glycolate, Sodium Glycolate
- Skin conditioning agent – emollient – Lauryl Lactate, Myristyl Lactate, Cetyl Lactate
- Skin conditioning agent – humectant – Lactic Acid, Ammonium Lactate, Potassium Lactate, Sodium Lactate, TEA-Lactate
- Skin conditioning agent – miscellaneous – Lactic Acid
- Solvent – Methyl Lactate, Ethyl Lactate, Butyl Lactate
Glycolic Acid and Lactic Acid are alpha hydroxy acids (AHAs). They may be either naturally occurring or synthetic. They are often found in products intended to improve the overall look and feel of the skin. Glycolic acid is the most widely used of out of the group and is usually manufactured from sugar cane. Lactic acid, derived primarily from milk and its origins can be traced back to Cleopatra, who purportedly used sour milk on her skin.
The Food and Drug Administration (FDA) includes Lactic Acid, Calcium Lactate, Potassium Lactate and Sodium Lactate on its list of substances considered Generally Recognized As Safe (GRAS) as direct food additives. Ethyl Lactate and Butyl Lactate are also approved for use as direct food additives and Glycolic Acid (hydroxyacetic acid) is permitted for use as an indirect food additive in adhesives. The safety of Glycolic Acid and Lactic Acid, their salts and esters, has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that Glycolic Acid, Ammonium Glycolate, Sodium Glycolate, and Lactic Acid, Ammonium Lactate, Calcium Lactate, Potassium Lactate, Sodium Lactate, TEA-Lactate, Methyl Lactate, Ethyl Lactate, Butyl Lactate, Lauryl Lactate, Myristyl Lactate and Cetyl Lactate were safe for use in cosmetics and personal care products at concentrations of 10% or less, at final formulation pH of 3.5 or greater, when formulated to avoid increasing sun sensitivity or when directions for use include the daily use of sun protection. These ingredients were found safe for use in salon products at concentrations of 30% or less, at final formulation pH of 3.0 or greater, 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.
More safety Information:
CIR Safety Review: The CIR Expert Panel noted that products containing alpha-hydroxy acids (AHAs) may be for consumer use, salon use, or medical use. This CIR review did not address medical use. AHAs were absorbed by the skin; the lower the pH, the greater the absorption. Metabolism and distribution studies showed expected pathways and distribution. Consistent with these data, acute oral studies showed oxalate-induced renal calculi, an increase in renal oxalate, and nephrotoxic effects. No systemic effects were seen with dermal application, but irritation at the site of application was produced. While many studies were performed to evaluate AHA-induced skin irritation, it was common for either the AHA concentration or the pH of the formulation to be omitted, limiting the usefulness of the data. Clinical testing using AHA formulations of known concentration and pH was done to address the issue of skin irritation as a function of concentration and pH. Skin irritation increased with AHA concentration at a given pH. Skin irritation increased when the pH of a given AHA concentration was lowered. Repeat insult patch tests using lotions and creams containing up to 10% Glycolic Acid or Lactic Acid were negative. Glycolic Acid at concentrations up to 10% was not comedogenic and Lactic Acid at the same concentrations did not cause immediate urticarial reactions. Glycolic Acid was found to be nonirritating to minimally irritating in ocular tests, while Lactic Acid was found to be nonirritating to moderately irritating. In vitro testing to predict ocular irritation suggested Glycolic Acid would be a minimal to moderate-severe ocular irritant, and that Lactic Acid would be a minimal to moderate ocular irritant. Developmental and maternal toxicity were reported at the highest dose level. No developmental toxicity was reported at levels that were not maternally toxic. AHAs were almost uniformly negative in genotoxicity tests and were not carcinogenic. Because AHAs are exfoliating ingredients, the CIR Expert Panel assessed the potential that AHAs could increase the effects of UV radiation. Based on the results of extensive clinical testing, the CIREP concluded that any increase in the sensitivity to light was modest and could easily be controlled through formulation techniques or through product labeling directing the use of sunscreens.
More information about AHAs.
Link to FDA Code of Federal Regulations for Lactic Acid, Ethyl Lactate, and hydroxyacetic acid (Glycolic Acid)
Most of the AHA ingredients may be used without restriction in cosmetics and personal care products marketed in the European Union. TEA, listed in Annex III of the European Cosmetics Directive, is permitted at a maximum concentration of 2.5% in cosmetic products. TEA used in cosmetics and personal care products in Europe must comply with the following limitations: Purity minimum 99%, less than 0.5% secondary amines (concerns raw materials), less than 50 ppb nitrosamines, no nitrites.
Link to the EU Cosmetic Regulation:
Health Canada permits Alpha-Hydroxy Acids, including but not limited to Glycolic Acid, Lactic Acid, and Ammonium Glycolate, in cosmetics and personal care products at concentrations equal to or less than 10%, with a pH equal to or greater than 3.5, provided they are safe for their intended use, carry cautionary statements, and have restricted label claims. Preparations containing higher concentrations of AHAs may be permitted if the manufacturer provides Health Canada with evidence of their safety, pH levels, and directions for use, and cautionary statements are such that contact of the product with the skin is of limited frequency and duration.
Link to the Health Canada website:
The Joint FAO/WHO Expert Committee on Food Additives has not limited the Acceptable Daily Intake of Lactic Acid. No safety concern at current levels of intake were noted when Lactic Acid is used as a flavoring agent.
The European Commission’s Scientific Committee on Cosmetic Products and Non-Food Products Intended for Consumers (SCCNFP) updated position paper concerning Consumer Safety of Alpha-Hydroxy Acids http://ec.europa.eu/health/ph_risk/committees/sccp/documents/out284_en.pdf
Search the Code of Federal Regulations http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/cfrsearch.cfm
EU Cosmetics Inventory http://ec.europa.eu/consumers/cosmetics/cosing/