Laureth-21 is a chemical compound, alkyl polyethylene glycol (PEG (Polyethylene glycol)) ether of ethoxylated lauryl alcohol (21 mol).

The name describes the structure of the molecule. 

• "Laureth" is a term used to describe a group of ingredients derived from lauril alcohol that have been ethoxylated. 
• "-21" indicates that on average, there are 21 units of ethylene oxide in the molecule.

The synthesis process takes place in several stages:

• Step 1: Preparation of raw materials: lauryl alcohol and ethylene oxide.
• Step 2: Ethoxylation. Lauryl alcohol is reacted with ethylene oxide in the presence of a catalyst to form Laureth-21.
• Step 3: Purification. The resulting Laureth-21 is purified to remove unreacted lauril alcohol and ethylene oxide. This can involve various techniques, including distillation and filtration.
• Step 4: Drying. Purified Laureth-21 is then dried to remove any residual solvent.

Laureths belong to the family of alkyl polyethylene glycol (PEG (Polyethylene glycol)) ethers, compounds produced by the reaction of lauryl alcohol and one or more ethylene oxide equivalents.

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.

What it is used for and where

Laureth-21 is a compound used in the cosmetic industry, particularly in skin and hair care products. It is a type of surfactant, which means that it helps to reduce the surface tension of substances, making them more suitable for spreading and mixing with other substances.

Cosmetics

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.

Deodorant agent. When substances that give off an unpleasant odour are included in cosmetic formulations (typical examples are methyl mercaptan and hydrogen sulphide derived from garlic), deodorants attenuate or eliminate the unpleasant exhalation.

Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.

CAS: 9002-92-0