Monday, 12 February 2018

Is Sodium Lauryl Sulfate (SLS) really that bad?




I thought DAWN was supposed to be so gentle, little ducklings could use it! So why is SLS in it?!?

(Figure 1. Common household products containing Sodium Lauryl Sulfate. February 12, 2018)

What is Sodium Lauryl Sulfate?
Sodium Lauryl Sulfate is a chemical surfactant found in household cleaning products[1], shampoos[2], toothpaste[2] and some lotions[3]. Surfactants are commonly used as foaming agents, emulsifiers and detergents.[4] Sodium Lauryl Sulfate has many names, such as SLS[1], Sodium Dodecyl Sulfate[2], and Duponal[2].

The controversy:
There are several controversies with the use of Sodium Lauryl Sulfate in everyday products. The most common problems are that it causes skin and eye irritation[1,3], cataracts[1], cancer[1] and that it is banned in Canada[5]. Because of these controversies some companies do not use Sodium Lauryl Sulfate anymore, but it is still found in many products. 

The facts:
As scary as Sodium Lauryl Sulfate sounds, only some of these problems are true.

Firstly, Sodium Lauryl Sulfate is not banned in Canada.[3] In fact, Health Canada lists it as one of the most asked about consumer chemical on their website.[3] Secondly, there is no scientific evidence on Sodium Lauryl Sulfate causing cancer.[1] Those who make the claim that it is will link it to a study which used a car to burn Sodium Lauryl Sulfate.[1]

Although people with extremely sensitive skin may experience skin irritation after using products with Sodium Lauryl Sulfate, majority of people will not experience skin irritation if using products for small amounts of time. However, prolonged direct contact (24 hours or over) will increase chances of skin irritation.[1]
As for Sodium Lauryl Sulfate causing cataracts, it is false and the results of the experiment linked to this claim is questionable. The experiment involved applying 0.5mL of shampoo to animal eyes daily for 14 days.[1]

What now?
Although Sodium Lauryl Sulfate is not scientifically proven to be cancer causing, or cataract causing, it can cause skin irritation to some people. For those who have sensitive skin or do not wish to use Sodium Lauryl Sulfate, there are alternatives. The most common alternative is Sodium Laureth Sulfate, which is the gentler version and used widely by many companies.[5] However, making Sodium Laureth Sulfate can result in some cancer causing by-products which ARE banned in Europe and Canada.[6,7,8] Other safer options include Coco Glucoside, Sodium Lauryl Sarcosinate, Sodium Cocoyl Glycinate and Potassium Laureth Phosphate.[9]



References:

[1] Bondi, C.A.M., Marks, J.L., Wroblewski, L.B., Raatikainen, H.S., Lenox, S.R., Gebhardt, K.E. (2015)Human and environmental toxicity of sodium lauryl sulfate (SLS): Evidence for safe use in household cleaning products. Environmental Health Insights9 27-32 doi: 10.4137/EHI/S31765

[2] U.S. National Library of Medicine. (n.d.) Sodium Dodecyl Sulfate. Retrieved Feb 05, 2018 from
https://pubchem.ncbi.nlm.nih.gov/compound/Sodium_dodecyl_sulfate
[3] Government of Canada. (n.d.) Safety of cosmetic ingredients. Retrieved on Feb 05, 2018 fromhttps://www.canada.ca/en/health-canada/services/consumer-product-safety/cosmetics/labelling/safety-ingredients.html#a4.13
[4] The Essential Chemical Industry – online. (n.d.) Surfactants. Retrieved Feb 12, 2018 from
http://www.essentialchemicalindustry.org/materials-and-applications/surfactants.html
[5] Jendaz, L. (May 2015). Detox you home with essential oils. Retrieved from
https://www.slideshare.net/lisajendza/detox-your-homefinal-48797233
[6] SLS Free. (n.d.) Sodium Laureth Sulfate - the facts. Retrieved Feb 05, 2018 from
http://slsfree.net/sodium-laureth-sulfate-facts/
[7] Holtkamp G. (2012) The ban list: 7 ingredients to avoid in personal-care products. Retrievedfrom https://www.motherearthliving.com/Health-and-Wellness/ingredients-to-avoid-zmfz12jazmel  
[8] David Suzuki Foundation. (n.d.) The dirty dozen: Sodium laureth sulfate. Retrieved Feb 05, 2018from https://davidsuzuki.org/queen-of-green/dirty-dozen-sodium-laureth-sulfate/
[9] Romanowski, P. (n.d.) So you want to formulate SLS free? Retrieved Feb 05, 2018 fromhttp://chemistscorner.com/so-you-want-to-formulate-sulfate-free/    








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