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?
The following functions have been reported for Glycolic Acid, Lactic Acid and their salts and esters.
- Ingredients that minimize the change in the pH of a solution when an acid or a base is added to the solution. – Ammonium Lactate, Potassium Lactate, Sodium Lactate
- Ingredients that induce a tightening or tingling sensation of the skin. – Calcium Lactate
- Ingredients that help to remove dead skin cells from the skin surface. – Glycolic Acid, Lactic Acid, Ammonium Glycolate, Ammonium Lactate, Calcium Lactate, Potassium Lactate, Sodium Lactate
- Ingredients that slow the loss of moisture from a product during use. – Lactic Acid
- Ingredients that are used to control the pH of cosmetic products. – 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
- Substances, usually liquids, that are used to dissolve other substances. – 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” is an acronym for the phrase Generally Recognized As Safe. Under sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act (the Act), any substance that is intentionally added to food is a food additive, that is subject to premarket review and approval by FDA, unless the substance is generally recognized, among qualified experts, as having been adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excluded from the definition of a food additive.) 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 additives are additives that may become part of the food in trace amounts due to its packaging, storage or other handling. For example, minute amounts of packaging substances may find their way into foods during storage. in adhesives. The safety of Glycolic Acid and Lactic Acid, their salts and esters, has been assessed by the The Cosmetic Ingredient Review (CIR) was established in 1976 as an independent safety review program for cosmetic ingredients. The CIR Expert Panel consists of independent experts in dermatology, toxicology, pharmacolgy and veterinary medicine. The CIR includes participation by the U.S. Food & Drug Administration and the Consumer Federation of America. (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 A measurement of the acidity or basicity of a substance. pH is the negative logarithm (base 10) of the concentration of hydrogen ions in solution. Water has a concentration of hydrogen ions of 1.0 x 10-7, and thus has a pH of 7. A pH of 7 is considered neutral, a pH lower than 7 is considered acidic, and a pH higher than 7 is considered basic. 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.
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. Experiments performed in a test tube or another artificial, controlled environment, rather than in a whole animal. 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 Ingredients that impart a flavor or a taste to a product..
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/