Updated: Dec 8, 2021
If you've ever Googled the causes of a skin complaint or damaged hair, chances are someone on the internet has pointed the finger at SLS, or sodium lauryl (or laureth) sulfate, a common ingredient in beauty products, especially in shampoos.
A surfactant allows the oil and water molecules to bind together – its what's found in soaps and shampoos.
Is it harmful?
Our skin's outermost layer is specially designed to keep harmful stuff out, and this is where a surfactant can cause problems. Using a chemical that weakens this defence mechanism can potentially cause our skin harm. Also removing skin natural oils making your hair roots very week.
Researchers from Germany tested 1,600 patients for SLS irritancy and found 42 percent of the patients tested had an irritant reaction.
It's also important to note there's no scientific evidence SLS causes cancer, despite what you may read on the internet.
So why is it allowed?
So if it's known to be irritating to human skin, why don't the regulatory authorities ban its use?
For SLS to be considered dangerous, it would have to be in contact with the skin for a long period of time.
Who should avoid SLS?
People with a history of sensitive skin, hyperirritable skin and patients suffering from skin conditions such as atopic dermatitis (eczema), rosacea, hair loss and psoriasis are best to avoid products containing SLS.
There are many safer alternatives available (look for fatty alcohol ethoxylate, alkyl phenol ethoxylate or fatty acid alkoxylate on the label). If you think it might be SLS causing a skin irritation, stop the use of the product and ask your pharmacist or GP for advice. Skin care products also have hotline numbers on the packaging that can be contacted to report adverse effects.
Yousuf Mohammed, Dermatology researcher, at The University of Queensland.