Titanium dioxide (TiO2) is a naturally occurring compound that is mined, refined and processed into a fine powder. It is known for its exceptional opacity, brightness and high refractive index, making it an ideal ingredient in paint formulations. When added to paint, titanium dioxide scatters and reflects light, creating vibrant, long-lasting colors. It is this unique property that makes titanium dioxide the most widely used white pigment in the coatings industry.

The evidence also suggests that the toxicity of TiO₂ particles may be reduced when eaten as part of the diet. This is because proteins and other molecules in a person's diet can bind to the TiO₂ particles. This binding alters the physical and chemical properties of the particles, which influences how they interact with cells, tissues and organs.