Aluminum Hydroxide
Aluminum Hydroxide (CAS# 21645-51-2) is an inorganic compound listed in CosIng with functions including emollient, humectant, opacifying, skin protecting, and viscosity controlling. It is commonly used as a protective coating for Titanium Dioxide in sunscreen formulations, where it helps shield skin from Reactive Oxygen Species generated when TiO2 is exposed to UV light. It also appears in composite pigment technologies as a base material to achieve higher color coverage with less pigment.
As a coating on Titanium Dioxide, it protects skin from harmful Reactive Oxygen Species (such as Superoxide and Hydrogen Peroxide) produced when TiO2 is exposed to UV light. It also functions as an opacifying agent, emollient, and skin protectant in cosmetic formulations, and can improve color coverage efficiency in pigment systems.
The protective Aluminum Hydroxide coating on TiO2-based sunscreens can be depleted by chlorine in swimming pool water, reducing its protective effect; sunscreen should be reapplied after swimming in chlorinated pools.
