There has been a lot of discussion in the hair care industry about the benefits of SLS free shampoo. On the one hand proponents of natural hair care products claim that sulfate free shampoos are kinder to your hair and scalp. These claims are based on the belief that sodium lauryl sulfate is an irritant and that it damages the hair and also the scalp.
The SLS Free Debate
Supporters of SLS free shampoo point to the Cosmetic Ingredient Review (CIR) Expert Panel which concluded that SLS and Sodium Laureth Sulfate (SLES) were safe to use as cosmetic ingredients and neither the US, Canadian or UK governments have banned their use. Of the two SLES has been shown to have lower iritation potential on the skin but becuase of the lower relative manufacturing costs of Sodium Lauryl Sulfate this is used more in hair shampoos and other beauty products.
The pro-SLS camp state that without sulfates, shampoo cannot effectively remove oil and dirt in hair. They state that because sulfates are surfactants and they help the shampoo lather well and ensure that the other ingredients in the product are effectively dispersed.
The early natural shampoo products did not lather as well as their SLS based alternatives but the natural products industry addressed this and these days alternative surfactants are used to help the shampoo lather and cleanse. For example Aveda sls free use derivates from the babassu nut as a foaming agent.
SLS free – the other side of the argument
Exponents of SLS and SLES say that sulfates got a bad press when Bhanolamine Lauyrl Sulfates were found to contain an impurity called nitrosamine. Nitrosamine was discovered to be carcinogenic and because of this shampoo producers stopped using Bhanolamine Lauyrl Sulfates in their products.
These producers used Sodium Lauryl Sulfate and Sodium Laureth Sulfate instead since tests found that did not share similar impurities. However other tests in Germany have shown that SLES may cause hair loss.
Although the debate around sulfate free shampoo is likely to continue for a long time to come, more and more people are choosing a natural or organic lifestyle and sulfate free shampoos i.e. SLS free shampoos are part of that.