Aminomethylpropanol is a synthetic ingredient used in cosmetics as a pH adjuster. It is considered safe as it is currently used in amounts of 2% or less in cosmetic formulas.
Aminomethylpropanol can penetrate the upper layer of the skin, but does not go further, which means that it does not enter the body. It is believed to aid in the penetration of other skin care ingredients, which in some circumstances (such as exfoliating acids) can make them more effective while keeping their effective pH range stable.
Aminomethylpropanol can be found in all kinds of beauty products from serums and lotions to hair care formulations and dyes and so on. https://www.paulaschoice.com/ingredient-dictionary/ingredient-aminomethyl-propanol.html?q=Aminomethyl%20Propanol&fdid=ingredients