Last week, we talked about the chemical definition of a sulfate, and how some sulfates, like magnesium sulfate(epsom salt) are not only not bad for you, but beneficial. Furthermore, there are literally dozens of sulfate compounds naturally in the human body. Read Part I here.
Basically, the word sulfate has been hijacked.
So, why do so many companies make an effort to advertise their products as 'SULFATE-FREE'?
Well, that takes us to surfactants, which are what most people mean without knowing it when they use the word sulfate. And again, not all surfactants, but a few bad apples.
The term surfactant stands for Surface Active Agent. This refers to the fact that in solutions, surfactant molecules migrate to the surface and align themselves in a manner which reduces surface tension.
Part of the molecule is hydrophilic (water loving) while another part is lipophilic (oil loving). This means they can be compatible with both the oil phase and the water phase (normally, oil and water don't mix). A surfactant is usually made from a fatty acid(think oil, like coconut oil) that has been combined with sulfer(where sulf-ate comes from) to make the substance water soluble (able to be dissolved in water).
When cleaning, or washing your hair, for example, water will remove all the water compatible(soluble) ingredients, but dirt and oil(both insoluble, or, not able to be dissolved in water), need a surfactant to be removed. So surfactants are found in shampoos and body washes to make them able to do what they're made to do...remove dirt and oil.
Surfactants are also found in nature. Many plant species contain a class of chemical compound called saponins. Saponins are foaming agents, or, surfactants. In fact, our word 'soap' came from the word saponin, as 'sapo' is Latin for 'soap'. To be even more specific, 'sapo' comes from the plant name 'Saponaria', which we call 'Soapwort'.
Ever hear of soap nuts(the fruit of the Sapindus shrub),
or yucca root?
Hand made organic soap is really just another surfactant.
Some surfactants improve the look and feel of hair or skin. Commercial hair conditioners and even skin moisturizers usually contain one or more surfactants (betcha didn't know that).
Incidentally, surfactants have the added bonus of making foam. Lots and lots of foam. People like foam, especially in shampoo.
Surfactants are not harmful in and of themselves ...there is a whole range of surfactants. Some are derived from petroleum, and some are derived naturally from coconuts or vegetable sources. Some are contaminated with harmful chemicals, and some are not.
The surfactants that started the whole 'SULFATE-FREE' craze were SLS and SLES, which stand for Sodium Lauryl Sulfate, and Sodium Laureth Sulfate.
We'll address these two specific surfactants, and more, next week!