What it is
Potassium Stearate is a white powder with a subtle fatty odour.
What it does
Potassium Stearate is an emulsifier: it prevents the oily and liquid parts of a formula from separating.
It can also increase the thickness of the oil portions of cosmetic products.
Finally, Potassium Stearate has lubricating properties.
Potassium Stearate is generally considered to be safe.