6.0-8.0

The cytotoxic effect was tested through the colorimetric assay employing 3′-[1-[(phenylamino) -carbonyl]−3,4-tetrazolium]-bis(4‑methoxy-6-nitro) benzene-sulfonic acid hydrate (XTT) by reading the absorbance at 490 nm after 3 h of incubation post treatment [28]. The absorbance is proportional to the metabolic rate of viable (live) cells.

What is an exposure route? 

At the present JECFA meeting, the committee considered additional toxicological studies relevant to the safety assessment of the chemical that investigated its toxicokinetics, acute toxicity, short-term toxicity, long-term toxicity and carcinogenicity, genotoxicity, and reproductive and developmental toxicity, as well as special studies addressing its short-term initiation/promotion potential for colon cancer. The experts acknowledged that a large number of toxicological studies have been conducted using test materials, including nanoparticles, having size distributions and physico-chemical properties not comparable to real-world uses of titanium dioxide as a food additive. The studies on non-representative materials were evaluated by JECFA, but the committee concluded that such studies are not relevant to the safety assessment of the additive.

Recent analyses of food-grade TiO₂ samples have found that a significant portion of particles may be within the nanoscale. These particles (also known as nanoparticles) range in size from 1 to 100 nm, where 1 nm equals 1 billionth of a metre (the width of a typical human hair is 80,000 to 100,000 nm).

Macromolecular oxidation was detected in proteins by the colorimetric measurement of Advanced Oxidation Protein Products (AOPP) and in lipids by the colorimetric quantification of malondialdehyde (MDA). Standard curves were run with chloramine-T and 1,1,3,3 tetraethoxypropane (TEP) for AOPP and MDA methods, respectively [29], [30], [31]. Values were normalized to initial protein content in samples, measured with Bradford reagent [32]. The standard deviation of at least six measures was calculated and p-value < 0.05 were considered significant.

In Home Care products, the presence of titanium dioxide is declared in line with local regulations, which can vary across the world. In some countries, titanium dioxide is not declared if only a small amount of the ingredient is used. In other countries titanium dioxide is grouped under ‘colourants’ in the ingredients list. In Europe, regulation requires all home care ingredients to be disclosed through a supporting website. You can find our product ingredient information page by visiting ‘

A 2022 review on past studies of titanium dioxide and rat lung cancer, for instance, said the original study was under extreme conditions and its effects were not replicated in other animal species. Additionally, the review concluded that the few studies which did directly focus on titanium dioxide's impact on humans did not end up showing any increased cancer risk.

Are there any alternatives to toothpastes with titanium dioxide?

Titanium dioxide prices in India reached 3424 USD /MT and 3001 USD /MT for Rutile and Anatase grades during the last week of June.