If you’ve ever squinted at an ingredient list and wondered whether SLS, SLES, and SLSA are the same thing, you’re not alone. The names of these surfactants are nearly identical, making it confusing as to what each ingredient actually does and how it may affect your skin and body.

If you're looking for products without harmful ingredients; have someone in the family with sensitive skin or a chronic illness; or you’re choosing products for your little ones—that confusion can feel worrying. Is this ingredient safe for my family or will it leave my skin or scalp dry, red, or itchy?

We’re here to make it simpler. Below, we’ll break down what each ingredient is, how they differ, what the safety research actually says, and what to look for on a label.

Key Takeaways

• SLS (Sodium Lauryl Sulfate), SLES (Sodium Laureth Sulfate), and SLSA (Sodium Lauryl Sulfoacetate) are three different surfactants and foaming agents used in laundry and personal care products.

• SLS and SLES contain a sulfate group in their chemical makeup, classifying them both as sulfate surfactants. 

• Sulfates are skin and eye irritants, strip away natural oils in the skin, scalp, and hair, and can fade hair color.

• SLES is considered milder than SLS, however it is ethoxylated which means it may contain an unintended toxic carcinogenic byproduct of the ethoxylation process, 1,4 dioxane.

• SLSA isn’t a sulfate, is not ethoxylated, and is the mildest of the three.

• “Sulfate-free” isn’t a regulated claim. Instead of trusting a front label claim, look at the ingredient list to confirm.

• Branch Basics discloses every ingredient and its purpose, so you never have to guess.

A Quick Note on Sulfates

If you’ve ever flipped over a shampoo bottle or detergent bag to read the label, you’ve probably seen the word “sulfate”—whether it’s sodium lauryl sulfate (SLS) or sodium laureth sulfate (SLES), which are the most common.

These surfactants work like tiny go-betweens: the sulfate end of the molecule is attracted to water and the other to oil, so they can grab grease and dirt and carry it away when you rinse. That’s also what creates the bubbly lather many of us associate with “clean.”

Sulfates are effective and inexpensive, but they can be harsh on sensitive skin, hair, and scalp. That’s why another surfactant—sodium lauryl sulfoacetate (SLSA)—is a mild, effective and safe alternative. Contrary to its name, SLSA is not actually a sulfate at all, but it still cleans beautifully!

Let’s delve into the two most common sulfates: SLS and SLES, and what sets SLSA apart. 

What is Sodium Lauryl Sulfate? (SLS)

Sodium lauryl sulfate (SLS) is one of the most widely used sulfates in the world. It loosens grease and dirt so water can rinse them away, and it produces a thick, foamy lather.

Because it’s inexpensive and effective, you’ll find SLS in shampoos, body washes, toothpaste, bubble bath, and household cleaners, including industrial-strength degreasers and floor cleaners. It’s also among the sulfates in many conventional laundry detergents.

That same strong cleansing action is its drawback. SLS can strip the skin’s natural oils and disrupt its protective barrier, leaving skin or scalp feeling tight, dry, or itchy. It’s so reliably irritating that dermatology researchers use it as a model irritant when they study skin barrier damage, and animal studies show it irritates both the eyes and skin. The effect depends on concentration and how long it stays in contact, which is why people with eczema or sensitive skin often notice a difference when they cut it out.

What is Sodium Laureth Sulfate? (SLES)

Sodium laureth sulfate is a close relative of SLS. It starts from the same lauryl alcohol, usually derived from coconut or palm oil, but goes through an extra step called ethoxylation before it’s turned into a sulfate. That step adds small chains to the molecule, making it larger and less likely to penetrate the skin. 

This doesn’t make it irritation-free, though. SLES is still a sulfate, and for people with very dry or eczema-prone skin, it can contribute to skin sensitivities. That’s especially true in products that stay on the skin longer, like a long soak in the bath. 

The other concern you may have heard about is 1,4-dioxane. You will never see 1,4-dioxane on an ingredient list; it’s an unintentional contamination byproduct that can form during ethoxylation. We recommend you avoid ethoxylated ingredients (especially in personal care products used on the skin and hair) as 1,4 dioxane is considered likely to be carcinogenic to humans. 

Label tip: ethoxylated ingredients often include “-eth” in their names (laureth, ceteareth) oxynol in their names, or the letters PEG.

What is Sodium Lauryl Sulfoacetate (SLSA)?

Sodium lauryl sulfoacetate is a coconut- and palm-derived surfactant that lifts dirt and oil and creates lather. Despite the similar name, SLSA is not a sulfate. It’s a sulfoacetate, with a differently structured, larger molecule, so it’s less likely to penetrate and disrupt the skin barrier. This makes it more gentle on the skin, scalp, and hair.

It produces a rich, creamy lather, which is why it’s popular in bubble bars, bath bombs, solid and liquid shampoos, and cleaning products. We use it in our Laundry Detergent because it foams and is very effective at removing oil and dirt from clothes, while still fitting our sulfate-free promise. That’s why you’ll see Sodium lauryl sulfoacetate on the label.

Sodium lauryl sulfoacetate is also not ethoxylated, so 1,4-dioxane as a contamination byproducts isn't a concern. 

Is Sodium Lauryl Sulfoacetate safe? What the research says

The Cosmetic Ingredient Review (CIR) Expert Panel concluded in 1987 that SLSA is safe as a cosmetic ingredient at the uses and concentrations then in practice. In 2022, the panel re-evaluated SLSA and reconfirmed its safety, at reported use levels up to 2.5% in leave-on and 10.2% in rinse-off products.

The Environmental Working Group (EWG) has rated SLSA a “1” which is the safest rating an ingredient can earn. 

A Fragrance-Free Laundry Detergent with a Label You Can Read

We use sodium lauryl sulfoacetate (SLSA) in our Laundry Detergent because it’s a safe ingredient that isn’t irritating to the skin and scalp like SLS and SLES have shown to be.  It foams, it’s very effective at lifting oil and dirt from fabric, and it rinses clean.

We’re committed to full transparency on our labels, always. Where some companies leave ingredients off or hide them behind the catch-all “fragrance” or “parfum,” we list every ingredient and what it does, so you can feel confident about what you’re bringing into your home.

All of our products are fragrance-free and human-safe, giving you a simple, worry-free way to clean.

Sulfate-Free Label Tips

• Look for the full ingredient name, not just a “sulfate-free” badge. “Sulfate-free” isn’t a regulated claim, so it can mean different things from brand to brand.

• Watch for “-eth” or “PEG” in names, which signal ethoxylated ingredients.

• Be wary of “fragrance” or “parfum.” That single word can stand in for dozens of undisclosed chemicals.

• Choose brands that list every ingredient and explain what each ingredient does.

FAQs About SLSA and SLS

Is SLSA a sulfate?

No. Despite the similar name, sodium lauryl sulfoacetate is a sulfoacetate, which is a different chemical structure. That’s why products made with SLSA can be called sulfate-free.

Does more foam mean a better clean?

Not necessarily! Bubbles are mostly a sensory cue; what matters is how well an ingredient lifts dirt and oil, and SLSA does that well while still creating a lather.

Is SLSA ok for people with sensitive skin?

SLSA is considered mild and well tolerated by most people, though anyone with a known sensitivity should patch test and avoid inhaling the powder form.*

Is SLSA safe for babies?

SLSA is a common choice in gentle bath products and our powdered Laundry Detergent. It’s safe to use on baby clothes*, and is fragrance-free and contains no harsh chemicals.*  

*Note: Make sure that washing machines (especially front loaders) are not over stuffed with clothes so that the powdered detergent dissolves, circulates well, and is fully rinsed out. If necessary, consider a double rinse for babies, those with sensitive skin, or chronic illness. Another option to consider, in those cases, is our liquid laundry made from concentrate, our most gentle washing option.

Ingredient Choice Matters

Understanding the difference between these surfactants is important. Educated consumers are the driving force that create change in the cleaning industry. You vote with your dollar. If consumers won’t buy products with harmful ingredients, the industry takes notice. 

Our commitment to creating products that are human-safe, free of sulfates, and not ethoxylated make SLSA (Sodium Laurel Sulfoacetate) a perfect ingredient for our Laundry Detergent.