In food products, E171 is not a singular ingredient; it’s always combined with other ingredients (e.g., proteins and fats) in the food product. Digesting food is a slow process for the body compared to drinking a beverage, which passes much faster through the body. 

Exposure to titanium dioxide in utero and in breastfeeding children

Research has shown that, when ingested as a food additive, titanium dioxide and its nanoparticles can impact, alter, and/or damage important protective bacteria in the gut, along with the metabolic pathways of gut bacteria.

In summary, the gravimetric determination of titanium dioxide is an invaluable technique in industrial applications. Offering precision and reliability, this method supports various sectors that rely on the quality and consistency of titanium dioxide in their products. By employing effective gravimetric analysis, manufacturers can enhance their operations and maintain competitiveness in a demanding market. As industries continue to evolve, the importance of accurate material analysis remains a cornerstone of successful production practices, ensuring that titanium dioxide remains a key player in future innovations.

According to the EFSA's Expert Panel on Food Additives and Flavorings 2021 opinion regarding titanium dioxide, it could not rule out a concern for genotoxicity from ingestion of the material based on a perceived gap in data on this risk, which serves as the basis for current ban, said a March report on the decision.

Restraint

Earlier this year, a bill was introduced in the California legislature to ban the manufacture, sale and distribution of foods in the state containing titanium dioxide, along with four other harmful food chemicals. 

China’s government is working on its plan to eliminate outmoded capacities of TiO2 and strengthen environmental protection measurements. Small and middle-sized enterprises, with a production capacity under 50,000t/a, are the ones to suffer. They mostly get merged or need to withdraw from the market. Without their production capacity of about 500,000 tonnes yearly, the domestic output might shrink about 20%. This will enhance the power of listed companies in China immensely, which is one of the main reasons for the effort to go public.

In a 2019 study published in the journal Nanotoxicology, researchers recreated the first phase of digestion in mice and fed them titanium dioxide, then examined whether accumulation occurred in the organs. Researchers wrote: “Significant accumulation of titanium was observed in the liver and intestine of E171-fed mice; in the latter a threefold increase in the number of TiO2 particles was also measured. Titanium accumulation in the liver was associated with necroinflammatory foci containing tissue monocytes/macrophages. Three days after the last dose, increased superoxide production and inflammation were observed in the stomach and intestine. Overall, [this] indicates that the risk for human health associated with dietary exposure to E171 needs to be carefully considered.”

Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).

They are the only two sunscreen ingredients classified by the FDA as safe and effective. And though titanium dioxide is usually used in mineral sunscreens in the form of nanoparticles, evidence suggests that few, if any, particles penetrate the skin.