While IARC listed titanium dioxide as “possibly carcinogenic to humans,” they also add that “there is inadequate evidence in humans for the carcinogenicity of titanium dioxide.” Of the four human studies that they reviewed, only one showed a potential risk for occupational workers inhaling titanium dioxide particles and lung cancer, while the other three showed no risk for cancer at all. And it’s key to note that IARC did not assess the effects of titanium dioxide found in foods.

But that depends on how titanium dioxide is being used and how you might come into contact with it. The International Agency for Research on Cancer (IARC) has classified titanium dioxide as possibly carcinogenic to humans based on studies that showed more lung tumors in rats associated with breathing in titanium dioxide.

In general, nanoparticles have been shown to accumulate in the body, particularly in organs in the gastrointestinal tract, along with the liver, spleen, and capillaries of the lungs.

On the other hand, titanium dioxide is a synthetic mineral that is produced through a chemical reaction involving the mineral ilmenite or rutile. It is used in industries such as cosmetics, paint, and sunscreen as a whitening agent and pigment. The manufacturing process of titanium dioxide involves extracting the mineral from ores, purifying it through chemical processes, and then grinding it into a fine powder.