C9-11 Pareth-8 is the name assigned in the identification and standardisation system for cosmetic ingredients INCI (International Nomenclature of Cosmetic Ingredients) to a non-ionic surfactant that belongs to the group of ethoxylated fatty alcohols as regards its constitution. The structure of the substance is based on a C9-11 synthetic alcohol. Chemically, it is a polyethylene glycol ether of a mixture of synthetic fatty alcohols C9-11, with an average content of 8 moles of ethylene oxide. The global CAS identifier of C9-11 Pareth-8 is 68439-46-3.
At room temperature, C9-11 Pareth-8 is a clear or slightly clouded liquid that tends to delaminate. At the temperature of 40oC, the liquid substance has a faint yellowish colour, which is evaluated at maximum 70 on the Hazen scale. It exhibits a high solidification point, as it starts to solidify at approx. 13oC under the atmospheric pressure. As C9-11 Pareth-8 shows strong hydrophilic properties, it is very well soluble in water and also in lower aliphatic alcohols. The cloud point, characteristic for all substances that act as surfactants, is approx. 78-85oC. Then the water and oil phases of a solution separate, which in turn leads to growing cloudiness. Depending on the type of substances present, an emulsion, stable sol or a solution with sediment settling down is formed. Similarly to other structures derived from ethoxylated fatty alcohols, C9-11 Pareth-8 has moderate foaming properties. It is resistant to many environmental impacts – it shows unchanging activity in alkalis up to 90g NaOH/l; it is not affected by the presence of oxidising or reducing agents or the hardness of water used in the solution. Due to its non-ionic character, it can be an ingredient of formulations not only with similar surfactants, but also with entirely different ones: anionic or cationic surfactants. The substance is also fully biodegradable according to the biodegradability criteria laid down in Regulation (CE) No. 648/2004 on detergents.
Due to its detergent properties, C9-11 Pareth-8 is most commonly used as an ingredient of compositions of liquid cleaners for both hard surfaces and woven/knitted fabrics. It exhibits good wettability and a capacity to disperse impurities during water cleaning processes, which further enhances its detergency. As C9-11 Pareth-8 is suitable for use in both alkaline and acidic solutions, it is fit for household, industrial and institutional purposes. The compound is often encountered in multi-purpose liquid cleaners, chemicals dedicated for the bathroom and kitchen, floor cleaners and all types of degreasers, where it is used to remove greasy impurities from metal materials. When this chemical compound is used, the addition of a hydrotrope improves the solubility of C9-11 Pareth-8 in water, so the surfactant does not self-aggregate into micelles; if it is combined with an appropriate solvent, its stability also increases. Many formulations are based on the combination of different types of surfactants, and the use of non-ionic agents, including C9-11 Pareth-8, together with anionic ones gives a strong degreasing ingredient used for example in automotive chemicals. Due to its capacity to emulsify mineral oils, this chemical compound is useful in fibre pre-treatment processes. Due to that property, it can remove oil stains that often appear during knitting/weaving processes. Moreover, due to its strong wetting properties, C9-11 Pareth-8 enhances both the effectiveness of cotton bleaching and allows homogenous dyeing, as it pmproves the capillarity of dyes. As the substance forms micro-emulsions also with silicone oil, it is an excellent softening agent in formulations used in textile processes. According to Global Textile Research Institutes (Oeko-Tex Standard, ZDHC Programme), that define safety standards for textile products, C9-11 Pareth-8 complies with the requirements.
