Both Sodium Lauryl Sulfate (SLS) and its close relative Sodium Laureth Sulfate (SLES) are chemicals commonly used in many soaps, shampoos, detergents, toothpastes and other products that we expect to “foam up”. Both chemicals are very effective foaming agents, chemically known as surfactants.
A report published in the Journal of The American College of Toxicology in 1983 showed that concentrations as low as 0.5% could cause irritation and concentrations of 10-30% caused skin corrosion and severe irritation. National Institutes of Health “Household Products Directory” of chemical ingredients lists over 80 products that contain sodium lauryl sulfate. Some soaps have concentrations of up to 30%, which the ACT report called “highly irritating and dangerous”.
1. It is a known skin irritant. As highlighted in the research articles quoted above, even very small quantities of SLS are enough to irritate the skin. So much so, that when cosmetic companies need to test the healing properties of a lotion, they need to irritate the skin first. And guess what they use to do this? You got it right! SLS!! If you frequently suffer from dandruff, skin irritation or sores, it may very well be due to SLS.
2. It pollutes our groundwater. It is toxic to fish and other aquatic animals and has the potential for bioaccumulation (meaning it accumulates in the bodies of the fish.) It also is undetected in many municipal water filters, getting into the tap water that you drink.
3. It is actually a pesticide and herbicide. Did you know that SLS is commonly used to kill plants and insects? Makers of SLS recently petitioned to have SLS listed as an approved pesticide for organic farming. The application was denied because of its polluting properties and environmental damage. Imagine frothing this chemical on your skin now.
4. It emits toxic fumes when heated. Toxic Sodium Oxides and Sulfur Oxides are released when SLS is heated. Ofcourse, nobody expects to heat up a shampoo or soap, but a hot shower seems not quite nice now does it?
5. It has corrosive properties. According to the American College of Toxicity, this includes corrosion of the fats and protiens that make up skin and muscle. SLS can be found in garage floor cleaners, engine de-greasers, and car wash soaps.
6. Long-term permeation of the body’s tissues. A study from the University of Georgia Medicine showed that SLS had the power to permeate the eyes, brain, heart, and liver.
7. It’s an eye irritant. It was shown to cause cataracts in adults, and is proven to inhibit the proper formation of eyes in small children.
8. Nitrate and other solvent contamination. Toxic solvents, including carcinogenic nitrates are used in the manufacturing of SLS, traces of which can remain in the product.
9. Manufacturing process is highly polluting, emitting cancer-causing volatile organic compounds, sulfur compounds, and air particulates.
10. It helps other chemicals get into your body. SLS is a penetration enhancer, meaning that its molecules are so small they’re able to cross the membranes of your body’s cells. Once cells are compromised, they become more vulnerable to other toxic chemicals that may be included in the soap formulations along with SLS.
Does it cause cancer?
When SLS is mixed with triethanolamine (or T.E.A) carcinogenic substances called nitrosames can form and be released.
Products commonly found to contains Sodium Lauryl Sulfate or SLES
Tooth paste – even baby toothpastes. duh.
Washing-up liquid / dish soap
Childrens soaps / shampoos
Moisture lotion / Moisturiser
Unfortunately, there are over 150 different names by which it is known. Many products that are SLS-free will say it on the packaging, however it is wise to always study the ingredients. If you find out about any product which seems to carry deceptive labelling, do let us all know in the comments below.
NewsTarget “Popular Shampoos Contain Toxic Chemicals Linked to Nerve Damage” Mike Adams, January 11, 2005
MSDS Data Sheet for Sodium Lauryl Sulfate
MSDS Data Sheet for Sodium Laureth Sulfate
“OCA & Cancer Prevention Coalition Warn of Hidden Carcinogens in Baby Care” AScribe Newswire, Feb 28, 2007
“Technical Evaluation Report: Sodium Lauryl Sulfate” Compiled by ICF Consulting for the USDA National Organic Program, February 10, 2006
Environmental Working Group / Skin Deep http://www.ewg.org/skindeep