What Is Sodium Lauryl Sulfate (SLS) And Why You Should Avoid It

May 10, 2021 Gavin Whale

What is Sodium Lauryl Sulfate (SLS) And Why You Should Avoid It

What is Sodium Lauryl Sulfate (SLS)

Sodium lauryle sulfate (SLS) is an extremely common ingredient in many commercial soaps, shampoos, toothpastes and household cleaners. It started life in the 1930s as synthetic detergent to replace high alkaline soaps derived from lye and lard, primarily to wash clothes these soaps were aggressively harsh, but when SLS was created, no one would have dreamed of bathing in it. Today check the ingredients list on any commercial detergent from beauty, self-care products to household cleaners and the first ingredient will be a sulphate with SLS being the most common.

Sodium Lauryl Sulfate (SLS) is sometimes mistaken for Sodium Laureth Sulfate (SLES) though they have a similar chemical formula SLES contains ethanol and is slightly milder and less irritating than SLS.

How Sodium Lauryl Sulfate Works

SLS is known as a surfactant, this means that is lowers the surface tension between ingredients. This makes SLS an effective cleansing agent and an effective foaming/lathering agent.

Most beauty products are a liquid made up of oil and water mixed together, oils are hydrophobic which means that they do not mix with water. Surfactants allow water and oil molecules to bind together. So SLS is used to bind the liquid products together in the first place, but this also has an added benefit as when you place the liquid containing SLS onto an oily surface such as our oily hair or oily dishes, the oil from those surfaces will bind to the liquid stripping the oil from the surface. In simplistic terms SLS containing products clean up oils.

Why is SLS used?

Sodium lauryl sulfate is an effective surfactant, it is very cheap, easy to produce, it is in high abundance, it lathers extremely well and binds to oils extremely well. As soon as SLS containing shampoos hit the marketplace these new shampoos were revolutionary, they worked so effectively. Because it is so effective nowadays, you will find it almost everywhere; shaving cream, lip balm, hand sanitizer, nail treatments, makeup remover, foundation, facial cleaners, exfoliants, liquid soap, shampoo, conditioner, hair dye, dandruff treatment, styling gel, toothpaste, mouthwash, moisturisers, hair-removal cream and sun-cream... There's more but I think you get the idea!

You may remember another term for something that binds water and oils from your schooldays and that term is emulsifier. This term is used more when it comes to food and guess what? SLS is occasionally used as an emulsifier too, it can be found in dry beverage bases, dried egg products and some marshmallow products. This concerns me for reasons I will get on to next...

The dangers of sodium lauryl sulfate

In a scientific study on SLS I found, funded by a company called Seventh Generation who use SLS extensively in their products, they state that certain detergents and cleaners that contain SLS are safe to use unless they are misused, if misused the products can harm your skin, eyes or worse if inhaled. Misuse would include not wearing gloves and having these products in direct contact with your skin or using them more than once or twice a week. Now the study was a bit vague as to which products it was referring to I would like to assume the more household products, but the whole article looks extremely biased towards SLS to me, not surprising when it was funded by Seventh Generation who use SLS extensively. Seventh Generation are owned by Unilever and it is their 'eco-friendly' brand, their products are far from eco friendly it is blatant green washing by big business, so AVOID SEVENTH GENERATION products if you think you are making an environmentally friendly choice.

SLS is bad for your eyes

Sodium lauryl sulfate is bad for your eyes. In fact eyes exposed more often to SLS have an increased chance of forming cataracts and if your eyes have any pre-existing injuries exposure to SLS can slow the natural healing process of your eyes.

SLS is toxic to animals and aquatic life

SLS itself as a standalone ingredient is proven to be toxic to animals, it is allowed to be used because it's diluted when added to products. SLS by itself again has a LC50 between 1 and 13.9mg/L after 96 hours, for the non scientists among you that means it has been proven to be toxic to aquatic life.

SLS is bad for your skin

The Sulfate strips away the delicate layers of your natural moisturisers that protect both your skin and you hair. You need to be especially careful with SLS containing products if you suffer from skin conditions such as acne, eczema, dermatitis or psoriasis. Our skin's outermost layer of oil has been designed over millions of years of evolution to protect your skin, removing that layer entirely is bad as it leaves you more susceptible to allergens and infection. The SLS in its self is also proven to be a skin irritant, it is approved for use in cosmetics and personal care because the products are designed to be rinsed off after short applications. SLS is also proven to penetrate the skin and enter your fat cells I cannot find any scientific studies into the effects of this but I am going to guess it is not a good thing.

SLS is bad for your hair

You should be careful with hair products containing SLS if you suffer with dry hair, or you naturally have dense curly hair. Personally I would avoid it all together no matter what type of hair you have, SLS has been proven in studies on rats to leave deposits on detergent on the skins surface and in hair follicles which caused damage to the hair follicles... concerning when it is an ingredient in almost all shampoos.

The SLS cancer myth

There is allot of information out there that suggests that SLS use has links to cancer, but when writing and fact checking this article I could not find any hard evidence to suggest that this is true.

Watch out for these SLS free product ingredients

So you have read all that and now you want to avoid SLS, very good you are taking action against big business that puts profit before health. However, as we all know green washing is rife at the moment with big businesses like Unilever and their Seventh Generation brand... Just because a product does not contact SLS does not mean it does not contain a harmful sulphate chemical. Here is a quick list of sulfates to avoid.

Sulfates to avoid

Sodium Lauryl Sulphate

Sodium Laureth Sulphate

Ammonium Lauryl Sulphate

Sodium Xylenesulfonate

Sodium Coco Sulphate

Sodium C14-16 Olefin Sulfonate

TEA-Dodecylbenzenesulfonate

Sodium Trideceth Sulphate

Sodium Myristyl Sulphate

Making the switch from SLS

Just a quick word of warning to those of you who want to make the switch from SLS or other Sulphate based products, do not expect to see those bubbles or that easy lathering you are used to. It does not mean it is not cleaning you any better in fact your skin and hair will be allot healthier, but it is going to feel like a different experience from you are used to when you bath or shower. If you are insistent on bubbles to feel clean then look for products that contain surfactants that are derived from high grade amino acids and sugars.

If you do not currently know where to start to find products free from SLS have a look at our store we have in stock natural soaps, shampoos and conditioners in a wide variety of scents and they are cheap compare to many other natural soaps available online. We would appreciate the support more than you could imagine. All the soaps on our store are vegan, all natural, fragrance free, plastic free, cruelty free, parabens free and SLS free.