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
- 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.