Other experts say there is simply no conclusive evidence at this point that titanium dioxide is damaging to humans after ingesting. Kaminski in particular said the research studies cite health hazards that were found by using high doses of the product, which you would not normally see in food.

A  2023 study published in the journal Environmental Research, scientists examined the effect of titanium dioxide nanoparticles on important gut bacteria in mice. Their results showed “the growth inhibitory effects could be associated with cell membrane damage caused by titanium dioxide nanoparticles to the bacterial strains. Metabolomics analysis showed that TiO2 NPs caused alterations in multiple metabolic pathways of gut bacteria, such as tryptophan and arginine metabolism, which were demonstrated to play crucial roles in regulating gut and host health.” The researchers also found that four different neuroprotective metabolites “were significantly reduced” in urine and in vitro bacteria and vivo urine samples. The researchers concluded: “Increasing evidence implies that the gut microbiome plays a profound role in regulating host metabolism. Our results illustrated that TiO2 NPs hindered the growth of four beneficial gut bacterial strains.”

Titanium dioxide mainly comes from the earth’s crust, where it’s actually the ninth most common element. When processed, it becomes a fine powder with a vibrant white pigment.

UV–vis spectra were carried out in the supernatant of both vitamins@P25TiO₂NPs samples after centrifugation to measure the amount of unbound vitamin. Standard curves at 375 nm and 255 nm were done for vitamin B2 and C, respectively, using a Synergy BioTeK multi-mode microplate reader.

Barium sulfide is produced by carbothermic reduction of barium sulfate. Zinc sulfate is obtained from a variety of zinc products, often waste, by treatment with sulfuric acid.

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Recently, Yanagisawa et al. reported that the transdermal exposure (mimicking skin-barrier dysfunction or defect) of NC/Nga mice to TiO₂ NPs (15, 50, or 100 nm), in combination with allergen, aggravated atopic dermatitis-like lesions through a T-helper type 2 (Th2) dominant immune response. The study also indicated that TiO₂ NPs can play a role in the initiation and/or progression of skin diseases, since histamine was released, even in the absence of allergen.

Titanium dioxide (TiO2) is used in a variety of personal care products, including sunscreens, pressed powders, and loose powders, as a UV filter or whitening agent. In lotions and creams (dermal exposure), it is not a risk for adverse health effects. However, when titanium dioxide is inhalable—as it may be when in powder form—it is considered a possible carcinogen by the International Agency for Research on Cancer.Titanium dioxide nanoparticles do not appear to confer any unique health hazards.