In France, marketing of foodstuffs containing the food additive E171, corresponding to titanium dioxide, notably in the form of nanoparticles, has been suspended since 1 January 2020, due to concerns about potential carcinogenicity.

According to an opinion issued in 2019 by France's national Agency for Food, Environmental and Occupational Health & Safety (ANSES), based on studies carried out in vitro or in animals, there is uncertainty surrounding the carcinogenic potential of titanium dioxide in humans. The majority of in vitro studies have shown a genotoxic action. Animal studies have also shown alterations in gene expression, suggesting a possible carcinogenic effect. Lung tumours were observed in rats after inhalation or instillation of titanium dioxide.

In 2006, the International Agency for Research on Cancer (IARC) classified titanium dioxide among the group of substances which are possibly carcinogenic to humans via the pulmonary route, based on animal data. According to the European Chemicals Agency (ECHA), titanium dioxide is suspected of being carcinogenic.

As of late 2020, in France, titanium dioxide was present in around 250 drugs or cosmetics (lipsticks and sun screens) sold mainly in pharmacies.

As a precaution, titanium dioxide nanoparticles should be withdrawn from the composition of food products, food supplements, cosmetics and drugs. Given the absence of a generalised and lasting ban on use of this colouring agent, labelling and package leaflets should be read with care and, where possible, products containing it should be avoided.

©Prescrire 1 October 2021

Source: "Titanium dioxide: is it carcinogenic?" Prescrire International 2021; 30 (230): 243. Subscribers only.

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