foam corner guards

Overall, the Food Directorate's comprehensive review of the available science of TiO₂ as a food additive showed:

Lithopone is rather nontoxic, due to the insolubility of its components. It has been used in medicine as a radiocontrast agent. Lithopone is allowed to be in contact with foodstuffs in the US and Europe.^[1]

Conclusions

Specific gravity:

ZnSO4 + BaS + ZnS + BaSO4

In a study published in the journal Environmental Toxicology and Pharmacology in 2020, researchers examined the effects of food additives titanium dioxide and silica on the intestinal tract by grouping and feeding mice three different food-grade particles — micro-TiO2, nano-TiO2, and nano-SiO2.  With all three groups, researchers observed changes in the gut microbiota, particularly mucus-associated bacteria. Furthermore, all three groups experienced inflammatory damage to the intestine, but the nano-TiO2 displayed the most pronounced changes. The researchers wrote: “Our results suggest that the toxic effects on the intestine were due to reduced intestinal mucus barrier function and an increase in metabolite lipopolysaccharides which activated the expression of inflammatory factors downstream. In mice exposed to nano-TiO2, the intestinal PKC/TLR4/NF-κB signaling pathway was activated. These findings will raise awareness of toxicities associated with the use of food-grade TiO2 and SiO2.”

≤0.4

Then, there’s ultrafine-grade, also known as nanoscale titanium dioxide. This is used for its ability to scatter lightly as an ultra-fine powder. This gives it the ability to lightly absorb into the skin while providing a bit of transparency. Below, we’ll go more into the cosmetic uses of these two forms of titanium dioxide.

A 2023 study published in the journal Particle and Fibre Toxicology set out to examine the impact of titanium dioxide nanoparticles in mice “on the course and prognosis of ulcerative colitis,” by creating an ulcerative colitis disease model. Researchers found that the titanium dioxide nanoparticles significantly increased the severity of colitis. They also “decreased the body weight, increased the disease activity index and colonic mucosa damage index scores, shortened the colonic length, increased the inflammatory infiltration in the colon.” Researchers concluded: “Oral intake of TiO2 nanoparticles could affect the course of acute colitis in exacerbating the development of ulcerative colitis, prolonging the ulcerative colitis course and inhibiting ulcerative colitis recovery.”

Nanotoxicology “focuses on determining the adverse effects of nanomaterials on human health and the environment.”

For his part, Kaminski argues most of the studies have been in animals, and any effects found were minuscule. He and his team also contested some of the findings in a 2019 study that found no evidence of increased inflammation or changes in the GI tract.

Titanium dioxide (E 171) is authorised as a food additive in the EU according to Annex II of Regulation (EC) No 1333/2008.