MEA-lauryl sulfate is a chemical compound, the ethanolamine (MEA ) Organic-substituted inorganic salt of lauryl alcohol. MEA  is a chemical compound belonging to the first generation of ethanolamines, is a primary amine and is a strong alkaline agent, corrosion inhibitor and chemical intermediate and acts as both an amine and an alcohol.

The name defines the structure of the molecule:

• "MEA-" stands for Monoethanolamine, an organic compound with the formula HOCH2CH2NH2, a colorless and viscous liquid with a smell reminiscent of ammonia. It is used in the creation of detergents, emulsifiers and polishes.
• "Lauryl" refers to the 12-carbon alkyl chain, also known as dodecyl, derived from lauric acid, a medium-chain fatty acid found in various vegetable fats.
• "Sulfate" indicates that the compound is an ester sulfate. In the context of surfactants, this means that the hydroxyl group of alcohol (in this case lauril alcohol) has been replaced with a sulfate group, resulting in a compound that is an effective detergent and foaming agent.

The synthesis process takes place in several stages:

• Step 1: Preparation of raw materials: monoethanolamine (MEA) and lauryl alcohol.
• Step 2: Sulfation. Lauril alcohol is subjected to a sulphating reaction, where it reacts with sulfur trioxide to form lauril sulfate.
• Step 3: Neutralization. Lauril sulfate is neutralized with MEA to form MEA-Lauryl sulfate . This reaction involves the sulfate group of lauril sulfate and the amino group of MEA.
• Step 4: Purification. The resulting MEA-lauryl sulfate is purified to remove any unreacted MEA and lauryl alcohol. This is typically done through a series of washing and filtration steps.
• Step 5: Drying. Purified MEA-Lauryl sulfate is dried to remove any residual solvent.

Safety. 

Scientific literature agrees that MEA  has the ability to penetrate and absorb into the skin and cause skin irritation, especially on the scalp. The most relevant studies on this ingredient have been selected with a summary of their contents (1).

What it is used for and where

Cosmetics

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.

MEA-lauryl sulfate has the highest reported use concentration, with a concentration of 35 percent in hair dye formulations.

The CIR Panel also warned that this ingredient should not be used in cosmetic products where N-nitroso compounds can be formed (2).

CAS: 4722-98-9

References____________________________________________________________________

(1) Fiume, M. M., Heldreth, B. A., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., ... & Andersen, F. A. (2015). Safety assessment of ethanolamine and ethanolamine salts as used in cosmetics. International journal of toxicology, 34(2_suppl), 84S-98S.

Abstract. The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of ethanolamine and 12 salts of ethanolamine as used in cosmetics. Ethanolamine functions as a pH adjuster. The majority of the salts are reported to function as surfactants, and the others are reported to function as pH adjusters, hair fixatives, or preservatives. The Panel reviewed available animal and clinical data, as well as information from previous relevant CIR reports. Because data were not available for each individual ingredient and because the salts dissociate freely in water, the Panel extrapolated from those previous reports to support safety. The Panel concluded that these ingredients are safe in the present practices of use and concentrations (rinse-off products only) when formulated to be nonirritating, and these ingredients should not be used in cosmetic products in which N-nitroso compounds may be formed.

(2) Johnson Jr, W., Bergfeld, W. F., Belsito, D. V., Hill, R. A., Klaassen, C. D., Liebler, D. C., ... & Heldreth, B. (2020). Safety assessment of silk protein ingredients as used in cosmetics. International journal of toxicology, 39(3_suppl), 127S-144S.

Hollis, G. L. (Ed.). (1995). Surfactants Europa: a directory of surface active agents available in Europe. Royal society of chemistry.