Although you’re probably not aware of it, many skin care and beauty products contain chemicals that are commonly irritating. One example is sodium lauryl sulfate (SLS), which is added to things like cleansers and soaps.
What is sodium lauryl sulfate? In this article we’ll look closely at what this mystery ingredient does, plus products you’ll find it in and how you can avoid it.
What Is Sodium Lauryl Sulfate?
Sodium lauryl sulfate is a surfactant ingredient that helps bind together oil and water molecules. It also acts as an emulsifier or thickener.
It sometimes goes by other names, including sodium dodecyl sulfate and sodium laureth sulfate.
It’s found in skin care and household products, such as washes and detergents, to help them work better once they’re mixed with water. You’ll also find it in tiny amounts in some foods that have a foamy texture.
SLS can be derived from both natural sources, such as coconut and palm kernel oil, and also made in a lab synthetically.
One of the reasons you’ll find it in so many different products is because it’s cheap to produce, abundant, and it works well to create products that foam, lather and bubble.
The downside to applying products containing SLS to your skin is that they can be irritating and allergenic. That’s because SLS can remove protective oils from the surface of the skin, leaving it susceptible to dryness, inflammation and short-term damage.
Where It’s Found
You’ll find sodium lauryl sulfate in foamy, bubbly and soapy products, including:
- Facial cleansers
- Body washes and shower gels
- Hand soaps
- Bubble bath
- Cleaning products for your home
Foods that contain SLS include marshmallows, dried egg products and fruit juices.
While SLS on its own can be drying and problematic, it’s often used in combination with other harmful ingredients, such as perfumes, paragons and synthetic additives, making matters worse.
Is It Safe? Dangers, Risks and Side Effects
Is sodium lauryl sulfate harmful to humans? Certain human and animal studies have found that it can be mildly irritating to the skin when used in high amounts or with long exposure times.
For example, one small study found that SLS exposure over 24 hours caused some participants to experience water loss in the skin, changes in the skin barrier and other signs of inflammation.
It’s widely known that SLS is aggravating to sensitive skin, which is why it’s not included in many natural skin care products. It’s even more likely to aggravate the skin of people with topic dermatitis (eczema), rosacea and psoriasis.
If you use other drying ingredients, such as acne treatments, or you’re prone to dry skin normally, chances are high that this ingredient won’t agree with you.
Among people who are sensitive to SLS, they can potentially develop side effects such as:
- skin dryness
- peeling and scaling
- sore or swollen skin
What if you swallow it? Is sodium lauryl sulfate safe in toothpaste?
Research suggests that SLS can penetrate the skin and likely the mucous membranes in the mouth, however according to most experts, there’s no solid scientific evidence indicating that use of SLS products can cause cancer.
It’s only used in small amounts in most products, and it’s thought that not enough SLS can penetrate into the body to have long-term harmful effects.
On the other hand, some experts worry that when SLS is made it may potentially become contaminated with known carcinogens, such as 1,4-dioxane and ethylene oxide, which are known to be harmful to human health. However, studies to date don’t back this up.
According to the U.S. Food and Drug Administration, SLS is a safe multipurpose additive that can be added to foods like egg replacements and juices in tiny amounts without causing harm.
Why Is It Used? Potential Benefits
What does sodium lauryl sulfate do that makes it such a widespread ingredient? As mentioned above, it helps bind oil and water molecules together in soapy products. This allows products to trap grime, dirt, food and other junk and then wash them away.
Therefore, uses and potential benefits of SLS include:
- Breaking up and soaking up stains, debris and grease from things like carpets, dishes, etc.
- Removing excess oil and makeup from skin
- Removing food particles from teeth
- Thickening/emulsifying ingredients in certain foods
Is sodium lauryl sulfate banned?
No, it’s legal to use in the U.S. in many dermatological and household products, as well as some foods.
It might seem strange that this ingredient is known to be harmful to the skin, yet it’s still allowed to be added to many products. The reason it isn’t totally banned is because it’s added to products that are normally only used on the skin briefly, then rinsed off, such as washes and soaps.
Authorities believe that if it doesn’t make contact with the skin for a long time, then it’s safe to use.
In most countries, when a product is intended to stay on the skin for a long time, such as a lotion, it can legally contain no more than 0.05% to 2.5% SLS in order to limit the risk for negative reactions.
How to Avoid It
Some products containing SLS include a brief warning somewhere stating that there’s a chance the product could cause skin irritation, dryness or redness on sensitive skin. If you have sensitive skin, always read ingredient labels carefully, and opt for natural skin care products as much as possible, including those that are homemade or store-bought but labeled hypoallergenic and organic.
If you are going to use products containing SLS, try to avoid heating them and mixing them with very warm water, since this can open up the skin’s pores and lead to worsened reactions. One study found that warmer water caused SLS to lead to more skin irritation.
When it comes to avoiding it in foods, your best bet is to limit consumption of processed foods (such as bottled juices, frozen meals and liquid eggs) and read ingredient labels.
- Is sodium laureth sulfate safe for skin? This ingredient is used in many skin and household products and can be irritating, especially to sensitive or dry skin.
- SLS is added to things like cleansers, soaps, washes, detergents, toothpastes and even some processed foods.
- If you’re experiencing red, dry, itchy or peeling skin, read the ingredients in your skin care products (especially ones that are foamy and lather up with lots of suds and bubbles). Avoid those with sodium lauryl sulfate, and opt for natural, moisturizing ingredients instead.