Is SLS (Sodium Lauryl Sulfate) Bad For You?

SLS stands for Sodium Lauryl Sulfate.  SLS is a common ingredient in soaps, shampoos, toothpaste, laundry detergent, dishwashing liquid, liquid soap – basically, anything which foams, and which is designed to be rinsed off.

SLS’s cousin chemicals are SLES (Sodium Laureth Sulfate), ALS (Ammonium Lauryl Sulfate) and ALES (Ammonium Laureth Sulfate).  All of these chemicals perform the same task – they are surfactants, which means that they make things slippery.  Surfactants also create foam, like the suds when you lather up in the shower.

Without question, yes.  SLS has been tested by the FDA and classified as an irritant.  The Materials Safety Data Sheet for SLS says that it is:

·         Harmful if swallowed

·         May be dangerous if absorbed through the skin

·         Causes severe eye irritation

·         May cause a respiratory reaction if inhaled

Sounds scary, right?  The truth is that these effects are usually mild in the concentrations of SLS that you will encounter in most consumer products like shampoo.  The MSDS refers to high concentrations of SLS, and to long-term exposure.  This is why it is considered acceptable for SLS to be used in products – like shampoo – which are designed to rinse off.

However, it is widely acknowledged that some people are “unusually sensitive” to SLS.  In the same way that most people can inhale pollen without any problems, but some people spend the entire spring season in misery, most people can tolerate exposure to SLS.  But some people with sensitive skin will experience itching, rashes, redness, and acne outbreaks after even a small, “normal” exposure.

If you have dandruff, eczema, itchy red skin, or acne, consider going on an “SLS-Free Diet” for a week or two to see if this may be the cause.  SLS sensitivity is more common than some people think.  And unfortunately, Sodium Lauryl Sulfate itself is almost ubiquitous.  As a known irritant, SLS is probably the root cause of many problems which go undiagnosed.

Acne, redness, and/or itchy skin around the mouth, for example, is a classic symptom of SLS sensitivity.  Switch to an SLS-free toothpaste, or brush your teeth with baking soda for a week to see if it clears up.

If your hands and knuckles are red, raw, or itchy, switch to an SLS-free soap.  Dr. Bronner’s liquid soap is SLS-free, and works well as a liquid hand soap (simply dilute it 50/50 with water before use).  You can also use Dr. Bronner’s as a dishwashing liquid soap, or wear rubber dishwashing gloves.

Dr. Bronner’s works well as a shampoo, too.  L’Oreal recently released a line of sulfate-free shampoos and conditioners which are excellent for this purpose, albeit expensive.

There is no indication that SLS is carcinogenic. If you have received an email about the supposedly cancer-causing properties of SLS, please understand that this email has been floating around for decades. It contains no verifiable assertions, and there is no data to support it. This is yet another example of random hysteria, and should be disregarded.

It is a truism among many people that sulfates cause hair to fall out early, or to become brittle and break sooner than it should.  This is the belief which encouraged L’Oreal to release a sulfate-free shampoo and conditioner system.

This belief is strictly anecdotal at this point.  The relationship, if any, between sulfates and hair breakage is only significant after years of exposure – as happens when you grow your hair extremely long.  Remember that your hair grows about half an inch a month, so if your hair is three inches long, it is only six months old. 

There are no health benefits to Sodium Lauryl Sulfate, and many negatives.  Most of these negatives are in the category of irritation, which is fairly benign – unless you are the one who is suffering from chronic dandruff, of course!

The benefit to SLS is that it causes your cosmetic cleaning products to foam well.  It is cheap, which is why so many companies include it in their products.  Foaming is strictly a psychological matter, however.  The suds themselves are not what gets you clean.  They simply look “clean” to our aesthetics.  Your shampoo and other soaps would work just fine even without the suds.

Certainly if you switch to SLS-free products, you will not be missing out on some kind of valuable ingredient or health effect.  There is no down side to choosing SLS-free products, except the added expense.