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.”

Hemolysis was studied on suspensions of P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL), vitaminB2@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) and vitamin B2 (0.2 mg/mL and 0.02 mg/mL) were prepared and mixed with 500 μL of anticoagulated blood (donated by Laboratorio de Hemoderivados, UNC) in a rate of 1/10. A solution of NaCl 10% was used as the positive control and PBS as the negative control. Then, the samples were irradiated using the LED described above for 3 and 6 h to simulate the light penetration into the skin. Also, a set of samples was kept in the dark as control. Finally, the samples were centrifuged and the absorbance at 540 nm was measured in the supernatants. The experiment was reproduced twice; the standard deviation was calculated and p-value < 0.05 were considered significant.

The US and Canada, however, approve the use of titanium dioxide as a food additive. Canada's recent review of titanium dioxide reconfirmed its safety and pointed out that many of the toxicity studies the EU reviewed were not relevant to the safety of titanium dioxide as a food ingredient, and that the ban is based on an abundance of caution and uncertainty.

What are the different forms of titanium dioxide in beauty and personal care products?

Ultimately, most experts advise moderation, as titanium dioxide is typically found in processed foods that come with their own health risks.

Titanium dioxide is found in pretty much all makeup & sunscreen.

And studies have long shown that products applied to the skin end up in the bloodstream within half an hour. With penetration rates depending on where they are applied. Absorption rates for your face & scalp are 5-10 times higher than on other parts of our body (Hotchkiss 1994).

Not to mention that in 2005, the Environmental Working Group published a combination of two studies that found toxic chemicals in the umbilical cord blood of newborn babies born in the U.S. They screened for more than 400 chemicals, and an astounding 287 toxins were detected within the umbilical cord blood of these newborns. Of these 287 chemicals, 217 were neurotoxins, and 208 are known to damage growth development or cause birth defects.