Isoceteth-20 is a polyethylene glycol (PEG) ether derived from isocetyl alcohol, classified as a non-ionic surfactant. It is primarily used as an emulsifier, solubilizer, and dispersing agent in cosmetic and personal care formulations. Thanks to its ability to mix oils and water, Isoceteth-20 is commonly found in products such as creams, lotions, cleansers, and hair care products.
Chemical Composition and Structure
It is obtained through an ethoxylation process, where isocetyl alcohol (a fatty alcohol with 16 carbon atoms) is combined with 20 moles of ethylene oxide. The result is a compound with an amphiphilic structure, featuring a hydrophilic (water-loving) part and a lipophilic (oil-loving) part, giving the compound the ability to act as an emulsifier or solubilizer.
Physical Properties
Isoceteth-20 appears as a clear or slightly cloudy liquid with a mild odor. It is soluble in water and some organic solvents and has a high capacity to blend hydrophilic and lipophilic ingredients, making it ideal for creating stable emulsions.
Production Process
Isoceteth-20 is produced through an ethoxylation process, where isocetyl alcohol is reacted with ethylene oxide. This process creates a surfactant with excellent emulsifying and solubilizing properties, suitable for a wide variety of cosmetic formulations.
Preparation of Components: The main ingredients for producing Isoceteth-20 include long-chain fatty alcohols, such as isocetyl alcohol, and ethylene oxide. These components are weighed and prepared for the reaction.
Esterification: Isocetyl alcohol is treated with ethylene oxide in an ethoxylation process. This is done by heating the alcohol in the presence of ethylene oxide, which is slowly added to facilitate the reaction. The alcohol reacts with ethylene oxide to form a polymer, in this case, Isoceteth-20.
Reaction Monitoring: During the reaction, temperature and pressure are monitored to ensure the process proceeds correctly. The viscosity of the product is also checked to ensure it reaches the desired properties.
Purification: Once the reaction is complete, the produced Isoceteth-20 is purified to remove any impurities and chemical residues. This may include distillation or filtration processes to achieve a high-quality product.
Quality Control and Packaging: Finally, Isoceteth-20 undergoes quality control checks to verify its purity and functional properties. After analysis, it is packaged for distribution and use in cosmetic and skincare products.
Applications
Emulsifier: Used in creams and lotions to stabilize water-in-oil (W/O) or oil-in-water (O/W) emulsions, improving texture and product distribution on the skin.
Solubilizer: Employed in products like cleansers and toners to solubilize lipophilic ingredients, such as essential oils or fragrances, making them mixable with the aqueous phase.
Hair Care: Used in shampoos and conditioners to enhance the dispersion of oils and other active ingredients, improving cleansing and the feel of the hair.
Cosmetics - INCI Functions:
Surfactant - Emulsifying agent. Emulsions are thermodynamically unstable. Emulsifiers have the property to reduce the oil/water or water/oil interfacial tension, improve emulsion stability and also directly influence the stability, sensory properties and surface tension of sunscreens by modulating their filmometric performance.
CAS: 69364-63-2
Safety. The term 'eth' in Isoceteth refers to the ethoxylation reaction with ethylene oxide after which residues of ethylene oxide and 1,4-dioxane, chemical compounds considered carcinogenic, may remain. The degree of safety therefore depends on the degree of purity of the compound obtained. At present, no manufacturer is known to provide this information on the label.
Cosmetic Safety
PEG (Polyethylene glycol) polymerize condensed ethylene oxide and water and are referred to as polyethylene glycols, but they are actually complex chemical components, polymers bonded together. For example, plastic is polyethylene and has a hard consistency, while polyethylene aggregated with glycol forms a liquid. PEGylation is produced not only as heterification but also as transesterification, which is the transformation of an alcohol by an ester.
The number that appears after the abbreviation PEG represents the molecular weight, and the higher this number is, the less it penetrates the skin.
The term 'eth' refers to the ethoxylation reaction with ethylene oxide after which residues of ethylene oxide and 1,4-dioxane, chemical compounds considered carcinogenic, may remain. The degree of safety therefore depends on the degree of purity of the compound obtained. No manufacturer appears to provide this information on the label, at least as of the date of this review.
Kim MC, Park SY, Kwon SY, Kim YK, Kim YI, Seo YS, Cho SM, Shin EC, Mok JH, Lee YB. Application of Static Headspace GC-MS Method for Selective 1,4-Dioxane Detection in Food Additives. Foods. 2023 Sep 2;12(17):3299. doi: 10.3390/foods12173299.
Abstract. "Efficient detection methods must be developed for 1,4-dioxane due to its suspected status as a human carcinogen, which is highly mobile in food and environmental resources. In this regard, this experiment has been conducted to develop reliable and selective detection and measurement methods by using static headspace (SH) isolation, followed by gas chromatography-mass spectrometry (GC-MS). A new method was developed for determining the spiked 1,4-dioxane contents in a polyethylene glycol 600 (PEG 600). The optimal condition for SH-GC-MS was discussed. The representative ions of 1,4-dioxane and 1,4-dioxane-d8 in the SIM mode of MS are 88 and 96, respectively, and the peaks of the SIM mode were separated and confirmed. The linear range for the method covers 0.25 to 100 mg/L with a coefficient of determination (R2) ≥ 0.999. The method applicability was demonstrated by spike recovery across a variety of food additives (i.e., chlorine bitartrate, choline chloride, polysorbate 20 and 60, and PEG 1000). All spike recovery from the tested samples was in the range of 89.50-102.68% with a precision of 0.44-11.22%. These findings suggest a new analytical method for food safety inspection, and could be applicable for ensuring the safety of foods and environmental and public health on a broad scale."
Isoceteth-20 
