Titanium dioxide (TiO₂) was firstly applied in industrial production in 1923, which is  a white inorganic pigment. It has excellent whiteness and luminosity, high opacity,  good dispersion, covering and weather resistance, and chemical stability. All the above features make it the most ideal white pigment at present. It is reported that among the world's consumption of TiO₂, 60% is used for coatings, 16% for plastics, 14% for paper, 3% for printing inks and 7% for other uses.

In fact, TiO₂ is a very common food additive and cosmetic additive. In cosmetics, TiO₂ is mainly used as physical sunscreen, foundation and other products formula. It is used as a sunscreen by reflecting and scattering uv rays. In terms of food additives, TiO₂ (also known as E171) is the only available white element in food, its good color and lustre is conducive to enhance the selling point and competitiveness of products.

Back in 2010, the International Center for Research on Cancer reported that TiO₂ was potentially carcinogenic to animals, making food regulators in many countries confused and nervous. After nearly a decade of evaluation and discussion, the European Commission finally adopted Regulation (EC) Resolution 1272/2008 in 2020 to classify TiO₂ as a category 2 suspected carcinogen that may cause cancer through inhalation. The regulation will come into force in September 2021.

Currently, TiO₂ is rated as a "2B" carcinogen by the World Health Organization, But this refers to substances or mixtures that are less likely to cause cancer in humans, with insufficient evidence for cancer in animals and even less for cancer in humans. Nevertheless, studies on the safety of TiO₂ still have been questioned. In 2020, a study by researchers at the University of Massachusetts, Aster, found that the food additive TiO₂ may interfere with the gut microbiome, which can lead to colitis.

TiO₂ has long been used as a food additive. In recent years, because of growing concerns about its safety, many international companies have moved to stop using TiO₂as a food coloring additive. Notably, France already has a total ban on foods containing TiO₂, which came into force at the beginning of 2020.