The Case Against Sodium Laureth Sulfate

Narelle Chenery (pictured right), Director of Research and Development for Miessence and formulator of the world’s first certified organic skin and body care products, and member of the Australian Society of Cosmetic Chemists looks at the much maligned and often misunderstood chemical, sodium laureth sulfate.

Sodium Laureth Sulfate (SLES) is a chemical used universally in cosmetics, personal care and skin care products. Whilst SLES is often claimed to be natural because it can be derived from coconut oil, it is the manufacturing process that bears looking into.

Ethoxylation is a process that uses ethylene oxide, a known carcinogen, to manufacture ‘milder’ surfactants like SLES. Ethoxylated surfactants may be contaminated with 1,4- Dioxane (dioxane), an un-wanted by product of the manufacturing process.

Ethoxylated ingredients, including detergents, foaming agents, emulsifiers and certain solvents are identifiable by the phrase “PEG,” “Polyethylene,” “Polyethylene glycol,” “Polyoxyethylene,” “-eth-,” or “-oxynol-.”

Exposure to large amounts of dioxane can cause kidney and liver damage. Accidental worker exposure to large amounts of dioxane has resulted in several deaths. Symptoms associated with these industrial deaths suggest dioxane causes adverse nervous system effects. Laboratory studies show that exposure to dioxane over a lifetime causes cancer in animals. Dioxane may likewise cause cancer in humans.

  1. poison According to the Consumer Product Safety Commission, the presence of dioxane, even as a trace contaminant is cause for concern and the Commission continues to monitor its use in consumer products.
  2. Skin absorption studies demonstrated that dioxane readily penetrates animal and human skin during use of contaminated shampoos and other personal care products, although it is uncertain how much is available for absorption and how much evaporates instead of penetrating the skin. It also caused systemic cancer in a skin painting study.
  3. The Australian government have assessed the main risk for the general public for dioxane exposure is from consumer products containing dioxane as an impurity. A so-called ‘worst case scenario’ for daily intake is 7 micrograms, based on an assumed level of 30ppm dioxane in end-use products. This is claimed to be 1000 times ‘safer’ than levels where no adverse effects were observed in animal studies.
  4. However, overseas studies have shown dioxane levels to be much higher than the assumed ‘low’ level of 30ppm. Dioxane has been found in household products at the following levels: shampoos (50-300ppm), dishwashing liquid (3-65ppm), baby lotion (11ppm), hair lotions (47-108ppm), bath foam (22-41ppm) and other cosmetic products (6-160ppm).
  5. Two studies reported an increase in liver cancer of 50% and 64% in workers employed in workplaces where dioxane is present. The same authors also carried out a workplace exposure survey and reported that the majority of dioxane levels measured in workplaces were less than 3ppm! Although they claim the data was insufficient to speculate on the workplace exposure levels in the liver cancer studies.
    Scorecard, the internet’s most popular resource for information about pollution problems and toxic chemicals, lists dioxane as a recognised carcinogen and suspected cardiovascular or blood toxicant , gastrointestinal or liver toxicant , immunotoxicant , kidney toxicant , neurotoxicant , respiratory toxicant and skin or sense organ toxicant .
  6. However ‘safe’ dioxane is purported to be, it is still not something I would like to see in any amount in my personal care products. Some manufacturers may claim that the alarming facts previously mentioned are irrelevant because they are based on the product in it’s pure 100% concentrated form and not relevant for the diluted form found in personal care products. But think about it… no matter how you look at avocado oil, whether in it’s concentrated form, or diluted form, it still ain’t toxic!

My philosophy is if it is possible to create a product without the use of any harmful, or even potentially harmful, chemicals then do it! And it is certainly possible: the Miessence certified organic product range is living proof that skincare can be made with only beneficial 100% natural and organic ingredients.

1,4-Dioxane Factsheet. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, February 1995.
“1,4-Dioxane, CAS No. 123-91-1: Reasonably Anticipated to be a Human Carcinogen.” Tenth Report on Carcinogens. U.S. Department of Health and Human Services, Public Health Service, National Toxicology Program, December 2002.
Prohibited Ingredients and Related Safety Issues. U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Cosmetics Fact Sheet, March 30, 2000.

Full Public Report on 1,4-Dioxane, Priority Existing Chemical No.7. National Industrial Chemicals Notifications and Assessment Scheme, 2003.
Fact Sheet 1,4-Dioxane – Emerging Contaminant of Concern,4-Dioxane_Fact_Sheet.pdf
Scorecard Summary o 1,4-Dioxane

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