Laureth-9 is a chemical compound, alkyl polyethylene glycol (PEG (Polyethylene glycol)) ether of ethoxylated lauryl alcohol (9 mol).
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.
The name defines the structure of the molecule:
- Laureth is a contraction of 'lauryl ether'. "Lauryl" indicates that the compound is derived from lauryl alcohol, while "ether" refers to the type of bond between the lauryl alcohol and the ethylene oxide units.
- 9 indicates the average number of ethylene oxide units in the molecule.
The synthesis process takes place in different steps.
- Preparation of lauryl alcohol. Lauryl alcohol is obtained from coconut oil or palm kernel oil.
- Ethoxylation. Lauryl alcohol is reacted with ethylene oxide in a process called ethoxylation. This involves the addition of ethylene oxide units to the lauryl alcohol molecule. The number after 'Laureth-' (in this case, 9) indicates the number of ethylene oxide units in the molecule on average.
What it is used for and where
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.
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.
CAS: 9002-92-0, 3055-99-0
