What it is
Dioctyldodeceth-5 is a nonionic ethoxylated fatty alcohol derived from octyldodecanol (a branched C20 fatty alcohol) by reaction with approximately 5 moles of ethylene oxide. The ethoxylation process adds a short polyethylene glycol chain to the fatty alcohol backbone, giving the molecule both hydrophilic and lipophilic character. In cosmetic formulations it acts primarily as an emollient and emulsifier: the branched lipophilic tail imparts a smooth, non-greasy skin feel, while the ethylene oxide units help the ingredient disperse in water-based systems and stabilize oil-in-water emulsions. It is found in moisturizers, sunscreens, and skin treatment creams where it contributes to spreadability and texture. As with all -eth suffixed INCI names, the "5" denotes the average number of ethylene oxide units added per molecule.
Safety & warnings
As an ethoxylated ingredient (suffix -eth), Dioctyldodeceth-5 may contain trace levels of 1,4-dioxane and residual ethylene oxide as manufacturing byproducts. The FDA and industry guidance recommend purification steps (vacuum stripping) to minimize these contaminants; finished product levels are typically well below regulatory thresholds. The non-ethoxylated parent alcohol octyldodecanol is generally considered non-irritating at cosmetic use concentrations. No evidence of skin sensitization specific to this compound has been identified in the published literature.
Origin & sourcing
Synthesized by ethoxylation of octyldodecanol (2-octyldodecanol, CAS 5333-42-6), itself produced by Guerbet condensation (self-condensation) of two molecules of decanol (n-decyl alcohol). The resulting branched C20 fatty alcohol is then reacted with approximately 5 moles of ethylene oxide under pressure in the presence of an alkaline catalyst to yield the polyethylene glycol ether.
History
Ethoxylated fatty alcohols as a class have been used in cosmetics since the mid-20th century. Octyldodecanol-based derivatives gained prominence in the 1980s and 1990s as formulators sought branched-chain emollients offering lighter skin feel than straight-chain counterparts. Dioctyldodeceth-5 is listed in the EU CosIng cosmetic ingredient inventory and appears in the INCI naming system maintained by the Personal Care Products Council.
Questions everyone asks
What does the "5" in Dioctyldodeceth-5 mean?
The number 5 indicates the average number of ethylene oxide units attached to the octyldodecanol molecule during the ethoxylation manufacturing process. More ethylene oxide units generally make the ingredient more water-soluble and hydrophilic.
Is Dioctyldodeceth-5 safe for sensitive skin?
Ethoxylated fatty alcohols like Dioctyldodeceth-5 are generally considered mild at cosmetic use levels. As with other -eth ingredients, trace manufacturing byproducts (1,4-dioxane) are a known concern, but reputable manufacturers remove them during production and finished products are typically with
What type of products contains Dioctyldodeceth-5?
It is found in moisturizers, sunscreens, AHA treatment creams, and other leave-on skincare formulations where it contributes emolliency, emulsification, and a smooth skin feel without greasiness.
How is Dioctyldodeceth-5 related to octyldodecanol?
Octyldodecanol is the parent fatty alcohol from which Dioctyldodeceth-5 is derived. Ethoxylation of octyldodecanol with ethylene oxide adds hydrophilic character, converting a purely oil-soluble emollient into an ingredient capable of functioning as both an emollient and an emulsifier in water-based