Of all the surfactants, Sodium Lauryl Sulfate, SLS, is the most irritating to skin so it is normally combined with other surfactants to make it less irritating.
Ammonium Lauryl Sulfate (ALS) is less irritating than Sodium Lauryl Sulfate (SLS).
As you know, I, like most other natural hair bloggers, don't recommend sulfate shampoos.
Although it is one of the most irritating surfactants SLS is widely used in shampoos because it is:
- Not expensive
- Foams well
- Can be thickened easily
- It’s a very effective cleanser
Sodium Laureth Sulfate (SLeS) is less irritating than Sodium Lauryl Sulfate (SLS) too. Just like SLS, SLeS thickens easily but it has the additional benefits of:
- Foaming well in hard water
- Being less irritating to skin
Ammonium Laureth Sulfate has all the benefits of Sodium Laureth Sulfate (SLeS) but is even less irritating to skin.
So if we were to rank these four sulfates from most irritating to least irritating we would have:
- Sodium Lauryl Sulfate (SLS) - most irritating to skin and drying to hair
- Ammonium Lauryl Sulfate (ALS)
- Sodium Laureth Sulfate (SLeS)
- Ammonium Laureth Sulfate - least irritating to skin and drying to hair
Note SLES is not the same thing as SLeS:
- SLES = Sodium Lauryl Ether Sulfate
- SLeS = Sodium Laureth Sulfate
Overall, sulfates are effective at cleansing greasy hair but tend to make dry hair even drier.