Thiodipropionic Acid

What Is It?

Thiodipropionic Acid is a dicarboxylic acid that contains a sulfur group. It is used as an antioxidant in cosmetic and food products. Dilauryl Thiodipropionate, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate are diester derivatives of Thiodipropionic Acid with similar functions. This means that there is one carbon chain (with a chain length of 12 to 18 carbons) attached to each oxygen of the carboxyl groups. Among these ingredients, Thiodipropionic Acid and Dilauryl Thiodipropionate are most common in cosmetics and personal care products including eye and face makeup products, and skin care preparations.

Why Is It Used?

Thiodipropionic acid and its derivatives prevent or slow the deterioration of cosmetic and personal care products by inhibiting reactions that occur through contact with oxygen in the air.

Scientific Facts

Dilauryl Thiodipropionate, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate are antioxidants. These ingredients impede oxidation reactions and help to preserve the color and texture of finished cosmetics and personal care products.

Safety Information

The Food and Drug Administration (FDA) includes Thiodipropionic Acid, Dilauryl Thiodipropionate and Distearyl Thiodipropionate on its list of antioxidants that can be used in food packaging material. Thiodipropionic Acid and Dilauryl Thiodipropionate are also on the list of substances that are Generally Recognized As Safe (GRAS) as chemical preservatives for use in foods. The safety of Thiodipropionic Acid, Dilauryl Thiodipropionate, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that these six ingredients were safe for use in cosmetic and personal care products when formulated to be non-irritating.

CIR Safety Review:

The laboratory test data indicated that Dilauryl Thiodipropionate did not cause any effects when given in the diet at concentrations up to 3%. Thiodipropionic Acid was not genotoxic, nor was it a developmental toxicant. Dermal studies indicated that Thiodipropionic Acid and Dilauryl Thiodipropionate were not sensitizers or phototoxicants.

Although some formulations containing Dilauryl Thiodipropionate at concentrations up to 4% were irritating to some subjects, other formulations containing Dilauryl Thiodipropionate were not irritating to any of the subjects tested. Therefore, the CIR Expert Panel concluded that Thiodipropionic Acid, Dilauryl Thiodipropionate, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate ingredients were safe for use in cosmetic and personal care products when formulated to be non-irritating.

FDA: Link to Code of Federal Regulations for Thiodipropionic Acid and Dilauryl Thiodipropionate

Thiodipropionic Acid, Dilauryl Thiodipropionate, Dicetyl Thiodipropionate, Dimyristyl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate may be used in cosmetics and personal care products marketed in Europe according to the general provisions of the Cosmetics Regulation of the European Union.

Link to the EU Cosmetic Regulation: http://europa.eu/legislation_summaries/consumers/product_labelling_and_packaging/co0013_en.htm

The Joint FAO/WHO Expert Committee on Food Additives has recommended an acceptable daily intake (ADI) of 0-3.0 mg/kg body weight for Thiodipropionic Acid and Dilauryl Thiodipropionate.

More Scientific Information

Dilauryl Thiodipropionate, Dicetyl Thiodipropioante, Dimyristryl Thiodipropionate, Distearyl Thiodipropionate and Ditridecyl Thiodipropionate are diesters of fatty alcohols (lauryl alcohol, cetyl alcohol, myristyl alcohol, stearyl alcohol, tridecyl alcohol) and 3,3’-thiodipropionic acid (Thiodipropionic Acid). The diestres are used as antioxidants in cosmetic and personal care products, and Thiodipropionic Acid is used as a skin conditioning agent – miscellaneous.

Resources

Find out more about the regulation of Food Additives by the Food and Drug Administration

Food Ingredients and Packaging: http://www.fda.gov/Food/IngredientsPackagingLabeling/default.htm

Food Contact Substances: http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/default.htm

Substances Generally Recognized As Safe (GRAS): http://www.fda.gov/Food/IngredientsPackagingLabeling/GRAS/default.htm

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/