The disadvantage of Titanium Dioxide is that it's not cosmetically elegant, meaning it's a white, unspreadable mess. Sunscreens containing Titanium Dioxide are often hard to spread on the skin and they leave a disturbing whitish tint. The cosmetic industry is, of course, really trying to solve this problem and the best solution so far is using nanoparticles. The itsy-bitsy Nano-sized particles improve both spreadability and reduce the whitish tint a lot, but unfortunately, it also introduces new health concerns. 

This cytotoxic effect was also reported before; i.e. Natarajan et al. conducted an experiment that found a strong oxidative stress, morphological changes in mitochondria and substantial loss in the fusion of primary hepatocytes exposed to P25TiO₂NPs [52].