Are All Sulfates Bad?

Picture this: a shampoo bottle boasts all the right signs of a clean, ethical product. 100% recycled plastic, 100% vegetarian, logos from organizations that protect animals from cruel testing, claims of no toxic ingredients like parabens and phthalates.

Then come some confusing phrases: "no harsh sulfates," "no damaging sulfates."

Sulfates are chemical compounds that increase the cleaning power of shampoos and cleaning products. This cheap but reliable ingredient helps create the foamy lather effect many of us associate with the experience of bathing or cleaning.

Sulfates often support the petroleum industry, which is responsible for much of the pollution that contributes to climate change. During the manufacturing of products that contain sulfates, there is a risk of contamination from 1,4-dioxane, a chemical the Environmental Working Group [EWG] believes might be linked to cancer in humans. Some consumers simply find sulfates irritating to their skin or eyes.

Given those facts, it's easy to assume all sulfates are at least somewhat unhealthy, and that the idea of a sulfate that isn't harsh or damaging is basically an oxymoron.

But people frequently use the term "sulfates" to refer specifically to sodium lauryl sulfates [SLS] and sodium laureth sulfates [SLES]. These compounds are by far the most controversial in the sulfate category.

"Sulfate-free" shampoos don't contain SLS or SLES, but most of them do rely on some form of sulfate, according to Lizzy Trelstad, a chemist at Beaker. There is no regulation of the term "sulfate-free," so brands can employ it however they want.

Checking the ingredients on the back of a bottle labeled "no harsh sulfates" might turn up no SLS or SLES at all, but instead sodium sulfate and sodium lauryl sulfoacetate [SLSA]. These chemicals may technically be sulfates, Trelstad said, but it's true that they aren't harsh or damaging like SLS and SLES.

EWG has assigned sodium sulfate and SLSA a hazard score of 1 out of 10, meaning the organization doesn't view the substances as public health concerns. Unlike SLS, there is no reported risk of contaminating these chemicals during their manufacturing process.

SLSA has become a popular ingredient in shampoos that claim to be natural. Nonetheless, the compound can be synthetically produced, Trelstad said, citing her experience working with natural and synthetic personal care brands.

All of this is worth keeping in mind before writing off a product over the word "sulfate" alone. It's easy to be a little dogmatic about the ingredient, assuming vague label language like "no harsh sulfates" is designed to obfuscate something alarming, when it might simply be an imprecise choice of words.

Brands can use mild sulfates and still be ethical, but what's equally important is being direct and transparent with consumers. When healthy products have nothing to hide, there's no need for confusing claims.