Sodium Lauryl Sulfate and Sodium Laureth Sulphate: Why are they bad?.

It's that time again - Roll over your bottle of shampoo and take a look what is in the ingredients list.

  Sodium Lauryl Sulphate (SLS) is an anionic sulfactant and an organic salt derived from coconut and palm oils and is a common ingredient in many household products1. 
  SLS is one of the most common ingredients in a wide variety of products; it is therefore one of the most thoroughly researched anionic compounds.  Our knowledge of it's properties, applications, and environmental impact has been thoroughly studied.  SLS's purpose, like other detergent sulfactants, is to remove oil; and in the case of SLS in shampoos and soaps, from the skin1.
 

  According to research, SLS does not cause cancer as controlled studies on mice when ingested and tested on the skin revealed no negative result; however, studies have shown that it is a skin and eye irritant and can worsen per-existing skin conditions such as eczema and psoriasis.  The same studies have been conducted on animals and the same result had been produced1.  SLS is also an ingredient in toothpaste and there have been studies to suggest that while it dulls the sweet taste of the toothpaste it also interferes with fluoride which weakens the fluoride's effectiveness1.  In other words, if you want stronger enamel, you might want to turn to a toothpaste which does not include SLS. 

  It should also be noted that SLS is also used as a pesticide and herbicide.  As a result, it is a contaminant in ground water and generally should be avoided because of the environmental impact.

  Sodium Laureth Sulphate (SLES) is another detergent sulfactant which makes soaps and shampoos bubble and foam.  While a compound found in most shampoos, shower gels and facial cleansers, it can also be found in laundry detergents and dish soaps.  Not to be mistaken with Sodium Lauryl Sulphate, while these two compounds are often paired with each other, they are not the same.

  Unlike Sodium Lauryl Sulphate, which is an organic salt which comes directly from coconut or palm oil.  Sodium Laureth Sulphate, also derived from salt, in it's manufacturing process the compound ethylene oxide is added.  When mixing these two properties, there is a bi-product produced from this process called 1, 4 Dioxane2.   According to the International Agency for Research on Cancer ethylene oxide as a known human carcinogen and 1,4-dioxane as a possible human carcinogen2. There is also a risk that Ethylene Oxide can harm the nervous system and the California Environmental Protection Agency has classified it as a possible developmental toxicant based on evidence that it may interfere with human development. 1,4-dioxane does not easily degrade and can remain in the environment long after it is rinsed down the shower drain. Although, 1,4-dioxane can be removed from cosmetics during the manufacturing process by vacuum stripping, there is no easy way for consumers to know whether products containing sodium laureth sulfate have undergone this process2.  The industry panel which reviews the safety of cosmetics ingredients notes that sodium laureth sulfate can irritate the skin and eyes even though it is proven to be an irritant to the skin and eyes, they still add it to "Dermatologist Recommended" products sold at your Dermatology clinic.

  Health Canada has added both Ethylene Oxide and 1, 4 Dioxane to it's "Cosmetic Ingredients Hotlist"; however, both Environment Canada and Health Canada are not restricting their uses in cosmetics because the exposure from a single dosage is not considered to pose any significant danger to the person using it.  Unfortunately, because there have been no long term studies to prove this; it is my best educated guess that long term exposure to these chemicals even at low dosages could potentially harm an individual.  They most assuredly pose a harm to aquatic organisms and are most definitely in our drinking water.