What is it?
A cleansing and foaming agent made by joining coconut fatty acids to N-methyltaurine, a close relative of taurine, a compound found naturally throughout the human body. It is used mostly in rinse-off products such as shampoos, body washes, facial cleansers and foot and bath products, and at lower levels in some face powders. It is not a sulfate.
Key information
- The CIR Expert Panel concluded that sodium methyl cocoyl taurate and 19 related taurates are safe as used when formulated to be non-irritating.
- It is not a sulfate and is a different chemical from sodium lauryl sulfate.
- The concentrated raw material can seriously irritate eyes, which is why finished products must be formulated to be non-irritating.
More information
Sodium methyl cocoyl taurate is an amide made by reacting coconut fatty acids with N-methyltaurine or its sodium salt. Coconut fatty acids are a mix, roughly half lauric acid with myristic, caprylic, capric and other acids, so the ingredient's exact makeup varies from batch to batch. It is sold as a mixture with salt and water containing about 24 to 33 percent of the active ingredient. The Cosmetic Ingredient Review (CIR) reported 339 uses in 2015, almost all rinse-off, at up to 13 percent in rinse-off foot products and up to 6 percent in face powder.
The CIR Expert Panel reviewed it with 19 related taurates. It had low toxicity when swallowed by or applied to the skin of animals, did not damage genes in laboratory tests, and caused no allergic reactions in guinea pigs tested with the undiluted ingredient. In a 24-hour patch test at 40 percent, far above use levels, 2 of 11 people had slight to definite redness. The main hazard is to the eyes: it irritated rabbit eyes undiluted, was mildly irritating at 10 percent, and a laboratory test predicted severe eye irritation at 20 percent. Because irritation appeared above use concentrations and few tests were done at the highest use levels, the Panel concluded taurates are safe as used when formulated to be non-irritating. It also noted that this ingredient can help other ingredients pass through the skin.
It is not a sulfate, and its name has none of the markers the FDA links to 1,4-dioxane. Taurine, its parent compound, is present in the body in large amounts; a 70-kilogram adult carries up to 70 grams. Related ingredients reviewed in the same group include sodium methyl lauroyl taurate and sodium cocoyl taurate.
Sources: Cosmetic Ingredient Review: Safety assessment of alkyl taurate amides and taurate salts (2016); Cosmetic Ingredient Review: Quick reference table, safe-with-qualifications findings (2020); FDA: 1,4-Dioxane in cosmetics, a manufacturing byproduct
