Titanium dioxide as used in sunscreens is commonly modified with other ingredients to ensure efficacy and stability. Examples of what are known as surface modifier ingredients used for titanium dioxide include stearic acid, isostearic acid, polyhydroxystearic acid, and dimethicone/methicone copolymer.
Typically, this mineral is produced in two forms. The primary type is pigment-grade titanium dioxide, which utilizes its pigment to provide a look of sensitivity and brightness.
While loose titanium dioxide presents a problem, titanium dioxide within sunscreen formulations presents a much safer option than conventional sunscreen chemicals like oxybenzone and octinoxate. However, titanium dioxide may become dangerous when it is nanoparticle size. Generally, nanoparticles can be 1000 times smaller than the width of a human hair. Despite nanoparticles becoming increasingly common across industries, they have not been properly assessed for human or environmental health effects, nor are they adequately regulated. Researchers don’t quite understand the impacts nanoparticles could have on human health and the environment. However, because of their infinitesimally small size, nanoparticles may be more chemically reactive and therefore more bioavailable, and may behave differently than larger particles of the same substance; these characteristics may lead to potential damage in the human body or ecosystem.