Sodium Lauryl Sulfate (SLS)

What is it?

Sodium Lauryl Sulfate (SLS) is a strong, anionic surfactant. It is often confused with Sodium Laureth Sulfate (SLeS) and Sodium Lauryl Sulfoacetate (SLSa), which are both different (and milder) surfactants. This confusion is one of the #1 reasons people on the internet get mad at me. SLS is perfectly safe when used properly; learn more here.

Sodium Lauryl Sulfate (SLS) can also be found in some emulsifying waxes (Lanette® W, Vegarol EW 200) paired with cetearyl alcohol.

As of February 2025: I do not own SLS, have never worked with it, and have never shared a formulation using it. If I did own it I would probably use it for things like dish detergent and other household cleaners rather than for personal care products.

INCI

Sodium Lauryl Sulfate

Appearance

White powder

Usage rate

3–30%

Scent

Characteristic of surfactants—detergenty.

pH

9.75–10.25 (1% solution)

Charge

Anionic

Solubility

Water

Why do we use it in formulations?

Sodium Lauryl Sulfate (SLS) is an excellent cleanser and creates wonderful, luxurious lather. It’s also inexpensive.

Do you need it?

No; I don’t own it and have never worked with it.

Refined or unrefined?

Sodium Lauryl Sulfate (SLS) only exists as a refined product.

Strengths

Strong, inexpensive, effective surfactant.

Weaknesses

That strength can be irritating. Sodium Lauryl Sulfate (SLS) also has a pretty bad reputation, which it doesn’t really deserve. Learn more here.

Alternatives & Substitutions

I would choose something milder, like Sodium Coco Sulfate (SCS), Sodium Laureth Sulfate (SLeS), or Sodium Lauryl Sulfoacetate (SLSa).

How to Work with It

Wear a dust mask while working with SLS.

Storage & Shelf Life

Stored somewhere cool, dark, and dry, SLS should last at least two years.

Tips, Tricks, and Quirks

Sodium Lauryl Sulfate (SLS) is often confused with Sodium Laureth Sulfate (SLeS) and Sodium Lauryl Sulfoacetate (SLSa), which are both different (and milder) surfactants. This confusion is one of the #1 reasons people on the internet get mad at me. While SLS certainly can be irritating, so can many ingredients (traditional lye soap, for instance, would also be irritating to the skin if applied in high concentrations and left in contact with the skin for extended periods of time). SLS is not a carcinogen.

Recommended starter amount

100g (3.5oz)

Where to Buy it

 Buy it from an online DIY ingredient supplier or Amazon.

Some Formulations that Use Sodium Lauryl Sulfate (SLS)

I don’t own Sodium Lauryl Sulfate (SLS) or work with it.

Originally published on May 8, 2020