As for titanium dioxide, the FDA approved titanium dioxide for use as a food additive in 1966. The last time the agency reviewed the additive’s safety, according to the Guardian, was in 1973.

In food, titanium dioxide has a few different uses. Most notably, its food-grade form is used as a colorant to enhance and brighten the color of white foods such as dairy products, candy, frosting, and the powder on donuts. For foods that are sensitive to UV light, titanium dioxide is used for food safety purposes to prevent spoilage and increase the shelf life of food.

It's also added directly to food; mainly for coloring, but also as a thickener and to keep some powdered food, like confectioner's sugar, from clumping.   

In 2023, California and New York proposed banning several food additives that are banned in Europe but legal in the United States. Titanium dioxide was among the five proposed to be banned, but in September, the additive was removed from the list of additives from the California ban list.

Lithopone was developed in the 1870s as a substitute for lead carbonate (lead white), to overcome its drawbacks of toxicity and poor weathering resistance. Within a few years, titanium dioxide displaced lithopone to become the white pigment (PW6) par excellence in the industry and the world’s best-selling inorganic pigment. However, titanium is a product whose price is subject to large price variations due to product availability. These price increases affect the competitiveness of finished products, and so the search for an alternative to titanium dioxide has generated a variety of possibilities to optimise its use. 

In 2017, French researchers from the Institut National de la Recherche Agronomique (INRAE) were among the first to examine the effects of E171 nanoparticles on the body. They fed rats a dose of 10mg of E171 per kilogram of body weight per day, which was similar to human exposure in food. The research, which was published in Scientific Reports, showed that E171 was able to traverse the intestinal barrier, pass into the bloodstream, and reach other areas of the body in rats. Researchers also found a link between immune system disorders and the absorption of titanium dioxide nanoparticles. 

The gravimetric determination of titanium dioxide is vital for several reasons. First and foremost, it ensures product consistency and quality, allowing manufacturers to produce coatings and plastics that meet industry standards. In industries where color consistency is crucial, such as paint production, maintaining a uniform concentration of TiO2 is essential to achieving the desired opacity and brightness.

Total content (as ZnS add ZnSO4)