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.

Titanium dioxide prices varied across the Asia-Pacific region in this quarter. The supply disruption caused by Russia's invasion of Ukraine made the supply of the feedstock titanium concentrate even more problematic, and in the first half of the second quarter, a bullish market outlook prevailed. The decline in TiO2 market values in India has also been backed by a decline in demand from downstream industries like automotive and construction.

In May 2021, the European Food Safety Authority (EFSA) published an opinion that stated that titanium dioxide can no longer be considered safe when used as a food additive.

Micronized titanium dioxide doesn’t penetrate skin so there’s no need to be concerned about it getting into your body. Even when titanium dioxide nanoparticles are used, the molecular size of the substance used to coat the nanoparticles is large enough to prevent them from penetrating beyond the uppermost layers of skin. This means you’re getting the sun protection titanium dioxide provides with no risk of it causing harm to skin or your body. The coating process improves application, enhances sun protection, and prevents the titanium dioxide from interacting with other ingredients in the presence of sunlight, thus enhancing its stability. It not only makes this ingredient much more pleasant to use for sunscreen, but also improves efficacy and eliminates safety concerns. Common examples of ingredients used to coat titanium dioxide are alumina, dimethicone, silica, and trimethoxy capryl silane.

For those wishing to limit or avoid exposure to titanium dioxide in foods, there are some steps you can take. 

Titanium dioxide is the most widely used whitening pigment in the world and has been linked to adverse health effects, particularly genotoxicity and intestinal inflammation. It is applied as food coloring and a whitening agent to a wide variety of foods, including chewing gum, cakes, candies, breads and ice cream. 

Of the products that include the additive in their labels, Thea Bourianne, senior manager at data consultant Label Insights, told Food Navigator USA in May 2021 that more than 11,000 products in the company's database of U.S. food and beverage products listed titanium dioxide as an ingredient. Non-chocolate candy led those numbers at 32%. Cupcakes and snack cakes made up 14%, followed by cookies at 8%, coated pretzels and trail mix at 7%, baking decorations at 6%, gum and mints at 4% and ice cream at 2%.

In a study published in the journal Food and Chemical Toxicology in 2016, researchers investigated whether titanium dioxide exposure led to an increase in colorectal tumor creation in mice by using a colitis associated cancer model. By measuring tumor progression markers, the researchers found that mice given titanium dioxide experienced enhanced tumor formation in the distal colon.  There was also a decrease of cells that act as a protective barrier in the colon. The researchers wrote: “These results suggest that E171 could worsen pre-existent intestinal diseases.”

For research published in Archives of Toxicology in 2020, scientists fed one group of mice a solution containing titanium dioxide for one month, and compared it to those that did not receive the additive. They found “the richness and evenness of gut microbiota were remarkably decreased and the gut microbial community compositions were significantly changed” in the titanium dioxide group when compared with the control group. The tests also revealed that the titanium dioxide exposure could cause locomotor dysfunction, or mobility issues “by elevating the excitement of enteric neurons, which might spread to the brain via gut-brain communication by vagal pathway.” The researchers concluded: “These findings provide valuable insights into the novel mechanism of TiO2NP-induced neurotoxicity. Understanding the microbiota-gut-brain axis will provide the foundation for potential therapeutic or prevention approaches against TiO2NP-induced gut and brain-related disorders.”