Myth or Fact: Sulfate Shampoo breaks hair? - Part 1 of 2

I have recently had a flood of comments about SLS. I am going to spend this week tackling myth or fact namely



1. Does SLS break hair?

2. Is SLS carcinogenic (i.e causes cancer)

3. Is SLS an irritant.



However this series has to start with explaining what SLS is and therefore he we  have some vintage Natural Haven. (This was originally posted in October 2009, so if you are having a case of deja vu, c'est vrai)

Oil will always float to the top of
water. Even if you really mix the two, droplets will form but allow it
to settle for a few hours and the oil and water will naturally separate.
See the diagram below.



2. However have you noticed that when you
wash oily dishes with soap, the oil is lifted off?



The
reason this happens is due to surfactants ( don't stop reading now, I'll explain!!).
A surfactant is a special type of chemical. It has two parts

• Water
  loving part - usually refered to as a polar head - you know polar like
  the ice caps made up of water.
  
  


• Oil loving part - usually referred to as a tail ( or a lipid
  tail - lipid means oil). See the diagram below!

3. So what is so special about
surfactants like SLS?



Surfactants like sodium
lauryl sulphate (SLS) can interact with both oils and water. This is
really special because it means a chemist can therefore combine oil and
water WITHOUT the oil separating from the water. This means the oil can be dissolved in water.



This
happens because the surfactant helps create micelles. The diagram below shows you how the SLS arranges
itself in a water and oil mixture. It also shows how micelles can be
formed.



4. So what is a micelle?



In
the simplest system, there are three parts needed make a micelle -
oil, water and a surfactant - see the diagram below.



They
are special because they allow oil to dissolve in water and this is
really useful for shampoo





 

Next up - Part 2 of 2 - Is there evidence to support the theory that SLS Shampoo breaks hair?