**Titanium Dioxide in Sunscreen**

Megha Trivedi and Jenny Murase

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.68886

#### **Abstract**

Titanium dioxide has been used in various industrial and cosmetic applications due to its unique elemental properties. This substance has a refractive index higher than most other compounds (*n* = 2.6142, in comparison to water at 20℃ *n* = 1.33). This allows titanium dioxide to have an iridescent and bright quality. It has been used in the cosmetics industry for "whitening" and "thickening" in multiple make-up brands. As titanium dioxide has the ability to greatly absorb UV light, it has been used as a physical sunscreen for many years. Over time, newer formulations, including "nanoparticle" formulations, have been marketed for ease of consumer use. We aim to discuss the evolution of titanium dioxide in sunscreens over time, discuss its mechanisms of actions, and comment on the efficacy and safety of these products.

**Keywords:** titanium dioxide in sunscreens, titanium dioxide, skin, allergic contact dermatitis
