What Is It?

The Trideceth ingredients (Trideceth-2, Trideceth-3, Trideceth-4, Trideceth-5, Trideceth-6, Trideceth-7, Trideceth-8, Trideceth-9, Trideceth-10, Trideceth-11, Trideceth-12, Trideceth-15, Trideceth-18, Trideceth-20, Trideceth-21, Trideceth-50) are polyethylene glycol ethers of tridecyl alcohol. The number in the name indicates the average number of units of ethylene oxide in the molecule. In cosmetic and personal care products, the Trideceth ingredients are used in the formulation of a variety of skin care and hair care products.

Why Is It Used?

The following functions have been reported for the Trideceth ingredients.

  • Surfactant – cleansing agent: Trideceth-20, Trideceth-50
  • Surfactant – emulsifying agent: Trideceth-2, Trideceth-3, Trideceth-4, Trideceth-5, Trideceth-6, Trideceth-7, Trideceth-8, Trideceth-9, Trideceth-10, Trideceth-11, Trideceth-12, Trideceth-15, Trideceth-18, Trideceth-20
  • Surfactant – solubilizing agent: Trideceth-20, Trideceth-21

Scientific Facts

The Trideceth ingredients are produced by reacting ethylene oxide with tridecyl alcohol. The numerical designation refers to the average number of repeating ethylene oxide units in the molecule. Tridecyl alcohol is a fatty alcohol with 13 carbon atoms. The fatty alcohols in the other polyethylene glycol ether compounds reviewed by CIR include lauryl alcohol with 12 carbons, stearyl alcohol with 18 carbons, and cetearyl alcohol which is a mixture of cetyl alcohol (16 carbons) and stearyl alcohol.

Safety Information

The Food and Drug Administration (FDA) permits the Trideceth ingredients (polyoxyethylated tridecyl alcohol) to be used as indirect food additives. They may be used as defoaming agents in paper and paperboard, and in coatings of paper and paperboard used for food packaging. The safety of the Tridecth ingredients has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel as part of the review of the alkyl PEG ether group of ingredients. The CIR Expert Panel evaluated the scientific data and concluded that the alkyl PEG ethers including the Trideceth ingredients were safe as used in cosmetic products when formulated to be non-irritating.

CIR Safety Review:

Based on similar structures, the CIR Expert Panel determined that the alkyl PEG ether compounds, including the Trideceth ingredients could be reviewed together. Developmental and reproductive toxicity studies as well as mutagenicity data were all negative for these compounds. These compounds can irritate the skin. Therefore, the CIR Expert Panel concluded that the Trideceth ingredients, as well as the other alkyl PEG ether ingredients were safe as used when formulated to be nonirritating.

Small amounts of 1,4-dioxane, a by-product of ethoxylation, may be found in the Trideceth ingredients. The potential presence of this material is well known and can be controlled through purification steps to remove it from the ingredients before blending into cosmetic formulations.

More information about 1,4-dioxane.


Link to Code of Federal Regulations for the Trideceth ingredients

The Trideceth ingredients 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:

More Scientific Information

Trideceth ingredients are polyethylene glycol ethers of tridecyl alcohol that contain repeating ethylene oxide units. These ingredients are useful in cosmetics and personal care products as surfactant – cleansing agents, surfactant – emulsifying agents, and surfactant – solubilizing agents.


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

Food Ingredients and Packaging:

Food Contact Substances:

Substances Generally Recognized As Safe (GRAS):

Search the Code of Federal Regulations

EU Cosmetics Inventory