It’s well known spray tan knowledge that SLS is an ingredient to avoid in our aftercare products, but I often see confusion as to why and I often see SLES, which is a different compound, being mistaken for SLS. Let’s take a moment to clear these things up!
Sodium Lauryl Sulfate (SLS) and Sodium Laureth Sulfate (SLES) are a form of surfactants added to some beauty products to stabilize the mixtures of oil and water by reducing the surface tension at the point of contact between the oil and water molecules. In a much simpler explanation, surfactants allow the oil and water molecules to bind together. Although they have almost the same function, keep in mind that they have notable differences.
Sodium Lauryl Sulfate (SLS)- this chemical compound is added to beauty products to create foam and induce cleaning action on the skin. The benefits of SLS include its excellent cleaning properties thanks to its foamy lather, effective removal of oil-based makeup, and emulsifying properties.
This chemical, however, has quite a reputation for causing irritation in the skin when left on prolonged times. SLS has the ability to disrupt our skin's outermost layer by stripping off too much moisture that may result in dry or even cracked skin. To regulate this harmful effect, most countries limit the percentage of SLS in products to amounts of .05% to 2.5%. To be clear, this may not be a great ingredient for our skin, but its effect has not been proven to cause drastic harm to one's health.
Sodium Laureth Sulfate (SLES)- This, on the other hand, is a less irritating surfactant that is derived from SLS by introducing ethylene oxide. SLES is a much gentler compound that is less likely to aggravate the skin, yet still has the same cleaning and emulsifying benefit from its parent compound, SLS. SLES is popular among personal care products because it doesn't dull our skin's outermost layer, leaving our skin feeling smooth and nourished.
To wrap it up, Sodium Laureth Sulfate should not be confused with Sodium Lauryl Sulfate, as it is a better alternative due to it’s gentler effect on the skin barrier. When recommending products for our clients, it is essential to be mindful of the ingredients making up a product and to be knowledgeable about them!