Foaming agents are substances that create bubbles or foam when added to liquids, such as soap or shampoo. They help to increase the volume and create a more frothy or lathery texture. Full definition
They are normally used as foaming agents yet they are skin irritants and they produce Nitrosamine which is a substance that is linked to cancer formation. (babieslounge.com)
For that they add foaming agents such as sodium laureth sulfate. (treehugger.com)
The scalp has also been stripped of its natural oils from harsh foaming agents like sulfates and is no longer responding to the synthetic softeners for replenishment. (mindbodygreen.com)