Any discussion of SLS/SLES must include a discussion of 1,4 dioxane because the manufacturing process of SLS/SLES results in its being contaminated with 1,4 dioxane—a known carcinogen.

Sodium Lauryl Sulfate (SLS), Sodium Laureth Sulfate (SLES), and Ammonium Laurel Sulfate (ALS)

Sodium lauryl sulfate is a surfactant, detergent and emulsifier used in thousands of industrial cleaners and cosmetic products. It is present in nearly all shampoos, scalp treatments, hair color and bleaching agents, toothpastes, body washes and cleansers, make-up foundations, liquid hand soaps, and laundry detergents.

Although SLS originates from coconuts, the chemical is anything but natural.

SLS is mixed with sulfur trioxide or chlorosulfuric acid and then neutralized with aqueous sodium hydroxide (lye). SLS is the sodium salt of lauryl sulfate and is classified by the Environmental Working Group (EWG) Cosmetics Database as a "denaturant, surfactant cleansing agent, emulsifier and foamer," rated "moderate hazard."

Similar to sodium lauryl sulfate (SLS) is sodium laureth sulfate (short for sodium lauryl ether sulfate, or SLES), a yellow detergent with higher foaming ability. SLES is considered to be slightly less irritating than SLS. SLS goes by other names, including:

Sodium dodecyl sulfate
Sulfuric acid, monododecyl ester, sodium salt
Sodium salt sulfuric acid
Monododecyl ester sodium salt sulfuric acid
A13-00356
Akyposal SDS
Aquarex ME
Aquarex methyl
Ammonium lauryl sulfate (ALS) is another variation commonly put into cosmetics and cleansers to make them foam. ALS is similar to SLS, showing similar risks.

Sixteen Thousand Studies Document the Hazards of SLS

According to the Environmental Working Group's Skin Deep: Cosmetic Safety Reviews, research studies on SLS have shown links to:

Irritation of the skin and eyes
Organ toxicity
Developmental/reproductive toxicity
Neurotoxicity, endocrine disruption, ecotoxicology, and biochemical or cellular changes
Possible mutations and cancer
If you visit the SLS page on EWG's website, you will see a very long list of health concerns and associated research studies. In fact, you will also see mention of nearly 16,000 studies in the PubMed science library (as well as their link to that list) about the toxicity of this chemical.

A number of studies report SLS being damaging to oral mucosa and skin. This is not at all surprising since SLS is actually used as a skin irritant during studies where medical treatments for skin irritation require first using an intentionally irritating agent. A study appearing in Exogenous Dermatology confirmed SLS to be a very "corrosive irritant" to the skin—irritation which persisted in research subjects for 3 weeks. SLS exerts its damage by stripping your skin of protective oils and moisture.

SLS has also been linked to nitrosamines. Nitrosamines are potent carcinogens that cause your body to absorb nitrates, also known to be carcinogenic. For more information about SLS/SLES, please refer to http://articles.mercola.com/sites/articles/archive/2010/07/13/sodium-lau....