ANSES was asked by the minister for health, Marisol Touraine, and agriculture minister Stéphane Le Foll to re-evaluate the additive’s approval following the publication of a study in January this year which prompted safety concerns.
Its opinion, which can be read in full here (in French), concluded: “[…] Although the results presented in this publication do not allow EFSA’s evaluation to be challenged at this time, it highlights effects that were not previously identified, notably potential carcinogenic effects.
"The Agency therefore stresses the need to conduct, in accordance with detailed procedures and a timetable to be defined, studies necessary to [identify] the potential health effects associated with the intake of the food additive E 171.”
Researchers at France’s National Institute for Agronomic Research (INRA) claimed to show, for the first time in an in vivo setting, that titanium dioxide crosses the intestinal barrier and passes into the bloodstream, reaching other parts of the body. They found nano-sized particles in the animals’ livers, the absorption of which has been linked to immune system disorders.
Listed as E 171 in Europe, titanium dioxide (TiO2) is a food colouring, mainly used in sweets, chewing gum, bakery and sauces, which contains nano-sized particles. It gives a white, opaque or cloudy effect in foods, and is a principal component in sun cream because it reflects UV light as well as toothpaste and paint.
However, the UN's International Agency for Research on Cancer (IARC) has classified it as a possible human carcinogen.
Nanomaterials offer many new food industry applications - for instance they can make products creamier without the need to increase the fat content, intensify flavours and show when food begins to go off - but the long-term health effects are unknown.
Titanium dioxide is one of the five most common engineered nanomaterials used in daily consumer products, including food, according to a 2012 study.
Limit consumer exposure
Despite not being able to come to a conclusion based on the INRA study alone, ANSES scientists nonetheless recommended limiting the exposure of consumers, employees and the environment by "promoting safe products that do not contain nanomaterials and are equivalent in terms of function, efficiency and cost".
"Where hazards to human or environmental health are identified, the Agency recommends weighing up the utility to the consumer or the community of placing on the market such products containing nanomaterials, for which the benefits should be clearly demonstrated," it said.
It also wants to see a strengthening of the traceability of consumer products containing nanomaterials. “[This] is essential for risk assessment work, in particular by improving the reporting process implemented under the R-nano national portal, in order to provide a better description of the nanomaterials placed on the market, their precise uses and the associated population exposures.”
The Agency recalled the need to develop relevant toxicology study protocols, such as adequate physico-chemical characterisation and a detailed and reproducible protocol, as well as exposure studies to assess the health risks of products containing nanomaterials.
In 2009, Danish supplier Chr Hansen developed a natural white colour from calcium carbonate, CapColors White 100 WSS-P, which it claimed was the first non-chemical alternative to titanium dioxide available to coated confectionery and chewing gum manufacturers.
In 2014, Beneo launched a natural white colouring made from rice starch that could be used to replace TiO2, although it said at the time it was promoting the ingredient as a clean label solution (rather than for food safety reasons) as it allowed manufacturers to replace the e number E 171 with rice starch on the label.
Meanwhile in 2015, US coffee and snack chain Dunkin' Donuts pledged to phase out the whitening agent from the powdered sugar used in its doughnuts.