Sulfates in face wash and shampoo
On a label, sulfates are alkyl and alkyl ether sulfate surfactants such as SODIUM LAURYL SULFATE and SODIUM LAURETH SULFATE. Surfactants lift oil and dirt and make foam in face wash and shampoo. DermNet NZ says the lauryl form is more irritating than the laureth form. Poliage flags both by name.
Sulfate is a short label for a group of washing ingredients. This guide explains what the group covers, what NHS and DermNet NZ say, and what the Poliage flag does.
Which ingredients count
Poliage’s Sulfates flag matches alkyl and alkyl ether sulfate surfactants. The best known are:
- SODIUM LAURYL SULFATE, often shortened to SLS
- SODIUM LAURETH SULFATE, often shortened to SLES
- AMMONIUM LAURYL SULFATE
The group also includes salts of lauryl, laureth, coco and myreth sulfates with sodium, ammonium, magnesium, TEA, MEA, DEA and similar partners, about 120 CosIng names in all.
Some names that sound similar are not in the group. Plain inorganic sulfates such as sodium sulfate and magnesium sulfate are not. Sulfonates and sulfosuccinates are not either.
What a surfactant does
A surfactant is a surface-active ingredient. In a wash-off product it helps oil and dirt leave the skin or hair with the water.
DermNet NZ says washing removes excess oil, odor, make-up, sunscreen and dirt, and that the skin’s surface oil film is removed. It describes SLS and SLES as anionic surfactants, and says anionic surfactants foam and rinse off easily.
What NHS and DermNet NZ say
The sources are specific, and they cover particular uses.
- DermNet NZ says sodium lauryl sulfate is more irritating than sodium laureth sulfate.
- DermNet NZ says soaps and face washes can irritate and cause skin problems. It says problems are rare with modern synthetic detergents designed for sensitive skin and used appropriately.
- The NHS says aqueous cream is no longer recommended as an emollient. It says the cream contains sodium lauryl sulfate, which can cause skin irritation such as burning, stinging, itching and redness. The NHS adds that some people still find it helpful as a soap substitute.
- DermNet NZ lists detergents and wet work among common occupational irritants.
These statements are about SLS in a leave-on cream, about washing in general, and about SLS compared with SLES. None of them says every product with a sulfate irritates every person.
Reading the flag
A product page says “Contains” followed by the sulfate name and its function. A sulfate near the start of the list means a larger share than one near the end, because ingredients are listed from most to least.
The flag marks the ingredient when it is on your own avoid list. It does not rank products.
Face wash and shampoo are rinsed off. The same ingredient in a leave-on product stays on the skin longer, which is the case the NHS statement covers.
If a product stings
Talk to a doctor or pharmacist. DermNet NZ advises seeing a dermatologist for any concern about your skin or its care. A patch test, described in the patch testing guide, can help you try a new product on a small area first.
What this guide does not do
It does not call sulfates good or bad. It does not say a sulfate-free product suits anyone. A label can be misread, and a maker can change a formula without changing the barcode, so the label on the pack comes first.
Where this comes from
The group comes from Poliage’s own flag rules, which match CosIng names. The statement that SLS is more irritating than SLES, and the description of surfactants, come from DermNet NZ’s page on soaps and face washes. The aqueous cream statement comes from the NHS page on emollients. The note on detergents as irritants comes from DermNet NZ’s page on irritant contact dermatitis.