Titanium dioxide is an insoluble mineral, meaning it cannot dissolve in water. Known for its bright, white pigment, manufacturers use titanium dioxide in many different capacities, including in cosmetics, foods, and drugs. 

In a statement sent to USA TODAY on Sunday, Justin Comes, vice president of research and development for Skittles maker Mars Wrigley North America, said the company couldn't comment on pending litigation – but that its use of titanium dioxide and all Mars Wrigley ingredients are safe and manufactured in compliance with strict quality and safety requirements established by food safety regulators, including the FDA.

4. Solar Cells The photovoltaic industry is another critical area where anatase TiO2 is making an impact. As a semiconductor, it plays a role in dye-sensitized solar cells (DSSCs), providing a pathway for improving energy conversion efficiency in sustainable energy solutions.