Steareth-25 is a chemical compound, carbon chains alkyl polyethylene glycol (PEG (Polyethylene glycol)) ether of ethoxylated fatty stearyl alcohol (25 mol), from palm kernel oils and coconut oils and fats.

The name describes the structure of the molecule

• Steareth indicates the presence of an ethoxylated stearate-based surfactant.
• 25 represents the length of the polyethylene oxide (ethoxylate) chain in the molecule.

Raw materials used in production:

Ethylene Stearate (Steareth) - Primary base component of the molecule and acts as a surfactant.

Polyethylene Oxide (EO) - Polymer of ethylene oxide with a chain length of 25 units.

Step-by-step summary of its industrial chemical synthesis process. 

• Material Preparation - Preparation of ethylene stearate and the appropriate-length polyethylene oxide (EO).
• Esterification - Reaction of polyethylene oxide with stearic acid or its derivative to form the ethoxylated stearate surfactant.
• Purification - Purification of the product to remove any impurities or unwanted by-products.

Form - Often marketed as a solid waxy substance or in pellet form.

Color - Usually white or slightly yellowish, depending on impurities present in the raw material.

What it is used for and where

Cosmetics

Cleaning agent. Ingredient that cleanses skin without exploiting the surface-active properties that produce a lowering of the surface tension of the stratum corneum. 

Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities. 

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: 9005-00-9

Safety.

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. At present, no manufacturer is known to provide this information on the label.