What Are the Effects of Sodium Lauryl Sulfate?

Sodium lauryl sulfate, also known as Sodium dodecyl sulfate, usually consists of a mixture of sodium alkyl sulfates, primarily lauryl. It is white or light yellow crystal or powder at room temperature, has a special smell, decomposes in hot and humid air. Easily soluble in water and soluble in hot alcohol, has certain bactericidal activity. It is one of the commonly used surfactants with excellent decontamination, emulsification and foaming abilities.

Sodium lauryl sulfate can be extracted from natural sources such as coconut oil and palm kernel oil, or it can be produced in a laboratory setting.

Preparation method of sodium lauryl sulfate:

After the esterification reaction of dodecyl alcohol with concentrated sulfuric acid, it undergoes acid-base neutralization reaction to become SLS.

C₁₂H₂₅OH+SO₃(H₂SO₄·SO₃)→C₁₂H₂₅OSO₃H

C₁₂H₂₅OSO₃H+NaOH→C₁₂H₂₅OSO₃Na+H₂O

As an anionic surfactant, sodium lauryl sulfate is commonly used in cleaning products such as detergents, washing powders, and shampoos. It has good decontamination properties and can effectively remove grease, stains, etc. In addition, it has emulsifying, wetting and dispersing properties, which can increase the stability of cleaning products and reduce surface tension.

Sodium lauryl sulfate is widely used as a foaming agent in toothpaste, soap, shower gel, shampoo, and cosmetics. This ingredient is found in 95% of personal skin care products and household cleaning products.

Advantages of Sodium Lauryl Sulfate:

In personal care products, sodium lauryl sulfate has been an ingredient in shampoos since the 1930s. It acts as a surfactant, trapping oil and dirt in your hair so it can be better rinsed away with water. It is an effective foaming agent that helps create rich lather in products such as shower gels, hand soaps, facial cleansers and foams. Likewise, sodium lauryl sulfate helps create a foaming effect in toothpaste that helps remove food particles from your teeth.

In cleaning products, this ingredient is an effective surfactant used in household cleaning products to help remove oil and residue, such as food stains from carpets and clothing. Because of its ability to break down oil and grease, it is also an ingredient in many industrial cleaning products, such as engine degreasers and industrial strength cleaners.

In food additives, sodium lauryl sulfate is used as an emulsifier or thickener. For example, this ingredient helps make marshmallows and cake products light and fluffy. It also helps acids mix better with liquids, making juices taste better.

Complete uses of sodium lauryl sulfate:

It can be used as detergent and textile auxiliary, also used as anionic surfactant, toothpaste foaming agent, mine fire extinguishing agent, fire extinguisher foaming agent, emulsion polymerization emulsifier, pharmaceutical emulsifying and dispersing agents, shampoos and other cosmetic products, wool detergents, and detergents for fine silk and wool fabrics, auxiliaries in industrial fields such as textile, printing and dyeing, papermaking, oil fields and leather, flotation agent for metal mineral processing. As a processing aid in the food industry, it is commonly used in the production of cakes, beverages, egg whites, fresh fruits, fruit juice drinks, edible oils, etc.

The safety of sodium lauryl sulfate as an additive in personal care products and household cleaners has been criticized for years. Some people believe that this ingredient can irritate the skin and is not safe to use. But claims that this ingredient corrodes skin are inaccurate. Products containing SLS that are properly dosed and formulated will not necessarily cause skin irritation. Research published in Environmental Health Insights in 2015 found that there is no scientific evidence that skin contact with this ingredient causes hair loss, and that there is no scientific evidence that this ingredient is a carcinogen.

This ingredient has been rumored to be a carcinogen for some time. The Cosmetic, Toiletry, and Fragrance Associaton publicly clarified on its official website that there is currently no evidence that sodium lauryl sulfate causes cancer. The American Cancer Society also stated this. And the U.S. Food and Drug Administration (FDA) includes SLS on the list of multipurpose additives permitted as direct food additives. High doses of this substance may indeed irritate the skin. However, when used as a foaming agent in general bathroom products, the concentration is limited and is in compliance with standards around the world.