Sodium Lauryl Sulfate (SLS) or Sodium Dodecyl Sulphate is one of the ingredients you'll find listed on your shampoo bottle. however, unless you're a chemist, you likely don't know what it is. the chemical is found in many cleaning and beauty products, but it's frequently misunderstood. 

SLS is what's known as a " surfactant." this means it lowers the surface tension between ingredients, which is why it's used as a cleansing and foaming agent.

most concerns about SLS stem from the fact that it can be found in beauty and self-care products as well as in household cleaners.