The European Commission asked EFSA to publish an opinion on the studies, which cast doubt on the safety of the food additive titanium dioxide and its nanosized particles, and to advise whether the studies merit “re-opening” the existing opinion, which dates from 2016.
After evaluating the studies, the EFSA panel quizzed the authors on possible gaps; their answers can be read in the opinion.
“Altogether, the Panel concluded that the outcome of the four studies did not merit re‐opening the existing opinion of EFSA related to the safety of TiO2 (E 171) as a food additive,” the opinion reads.
However, senior food policy officer at European consumer rights association BEUC Camille Perrin questioned the Parma-headquartered authority’s conclusion, particularly in light of its own opinion on titanium dioxide.
“Whilst [this opinion] did not raise the alarm bell, it nevertheless highlighted some data gaps hindering the safety re-evaluation of E171. The Commission has since then called on industry to provide information on the particle size and particle size distribution for titanium dioxide, because of the potential toxicological impact.”
'If uncertainties remain, it should not be used'
Perrin said tests by French consumer group UFC–Que Choisir and other NGOs have revealed the presence on the French market of popular foods, such as sweets and cakes, containing undeclared nanoparticles of E171.
“This was confirmed by official checks by the French control authorities, who have reminded food makers of their obligation under EU food labelling rules to label nano-ingredients in their products.
“So long as uncertainties remain over the safety of titanium dioxide, this additive should no longer be used in our food, especially given that it mostly serves aesthetic purposes. We commend the French government for proposing a measure in that sense, which is soon to become law.
Perrin praised French confectionery manufacturers that have already pledged to remove E171 from their products by 2020, and called on other European manufacturers to follow suit.
The four studies EFSA evaluated were: “Risk assessment of titanium dioxide nanoparticles via oral exposure, including toxicokinetic considerations” by Heringa et al. published in Nanotoxicology Journal;
Of this study, EFSA said: “There was significant uncertainty in the risk assessment performed by Heringa et al. which did not include a weight of evidence analysis of the whole database.”
“Food-grade TiO2 impairs intestinal and systemic immune homeostasis, initiates preneoplastic lesions and promotes aberrant crypt development in the rat colon” by Bettini et al. in Scientific Reports;
The EFSA panel concluded: “The results of the Bettini et al. study did not provide enough justification for a new carcinogenicity study, but, should additional useful mechanistic information become available, this could be reconsidered in future.”
“TiO2 induces ROS formation and genotoxicity: contribution of micro and nano-sized fractions” in Mutagenesis Journal by Prouquin et al;
EFSA scientists noted: “The new in vitro findings in the study by Proquin et al. did not modify the conclusion on the genotoxicity of TiO2 as stated in the previous  EFSA opinion on the safety of TiO2 when used as a food additive.”
They noted, however, that ongoing in vivo studies being conducted by Proquin’s team of researchers could be useful when they are completed.
“TiO2 nanoparticle ingestion alters nutrient absorption in an in vitro model of the small intestine” by Guo et al. in NanoImpact.
“The effects of engineered TiO2 nanoparticles reported by the Guo et al. study were of uncertain biological significance and therefore of limited relevance for the risk assessment of the food additive TiO2.”
Food manufacturers argue that alternative food colourings with the same functionality are not easy to find.
Michelle Maynard, executive director of the Food Additives and Ingredients Association (FAIA), previously told us: “Titanium dioxide possesses quite unique properties, as its refractive index gives it a high level of opacity and whiteness, which other materials do not have. Other techniques for imparting opacity and whiteness to food products are being sought by food manufacturers, but they will not be as technically effective as titanium dioxide.”
This week, EFSA also published guidance on assessing the risk involved in using nanotechnology in food.
Intended in particular for risk assessors and risk managers, the guide contains practical suggestions on the types of testing that are needed and the methods that can be applied, covering novel foods, food contact materials, food and feed additives and pesticides.