New Japanese study reinforces the safety of titanium dioxide

A new independent study by the Japanese National Institute of Health Sciences (NIHS) recently published in Particle and Fibre Toxicology[i] shows no toxic effects from the oral ingestion of titanium dioxide (TiO2).

The 28 and 90 day study was conducted to address a concern raised by the European Food Safety Authority (EFSA) that a data gap for nano TiO2 particles meant that a link to genotoxicity could not be ruled out.

The study directly addressed the EFSA’s concern for genotoxicity by evaluating a sensitive key marker for DNA strand breaks and a conventional genotoxicity endpoint (micronuclei). This showed that no adverse effects were observed in the liver and other tissues where trace amounts of titanium were detected. The study also showed no adverse effects in the colon.

The study used a nanoform of TiO2 with an average particle diameter of 6nm, which is 16 times smaller than the average particle diameter of E171, the type of TiO2 used as a food additive. The smallest average particle size of E171 was determined by several independent measurements. A dispersant was used in the preparation of the feed to prevent particle agglomeration and to maximise exposure to the particles. The study was carried out to Organisation for Economic Cooperation and Development (OECD) standards, which is the highest benchmark for this type of study.

The NIHS study also answers a concern raised by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES), in their opinion on the risk assessment of the nanometric fraction of the food additive E171 dated 27 November 2022, that there is no data on particles less than 10nm.

This study is consistent with conclusions published by Health Canada, Food Standards Australia New Zealand (FSANZ), the US Food and Drug Administration (FDA) and the interim findings of the United Kingdom’s Food Standards Agency (FSA), and reinforces the growing scientific consensus that TiO2 is safe to use as a food additive.

The new study reaffirms the need for a review of the EFSA’s opinion on E171 to ensure that the EU regulation is well-grounded in the available scientific evidence.

[i] Akagi, J. et. al. (2023) Oral toxicological study of titanium dioxide nanoparticles with a crystallite diameter of 6 nm in rats. Akagi et al. Particle and Fibre Toxicology.