E171 is a food additive used in many different food products for its colouring and opacifying properties. It consists of titanium dioxide particles, mainly in nanoparticle form, in varying proportions.
In 2017, ANSES published an expert appraisal of a study on the oral toxicity of E171 (NANOGUT study, Bettini et al., 2016) showing potential carcinogenesis-promoting effects in rats. At that time, the Agency stressed the need to conduct new toxicological studies in order to confirm or refute the effects reported in that study.
For its part, the European Food Safety Authority (EFSA), which is responsible for assessing food additives in accordance with European regulations, had stressed during its assessment of E171 in 2016 that the data on reproductive toxicity were inadequate to establish the acceptable daily intake (ADI) and the maximum level in foods without risks to consumer health.
In this context, in February 2019, the Ministers of the Economy, Health, Agriculture and the Environment asked ANSES to analyse the most recent knowledge on the toxicity of E171. The expert group set up by the Agency carried out a literature review on the oral toxicity of E171, and identified 25 new studies published since 2017.
Some of these studies revealed new signals, such as changes in cellular biological mechanisms in mice or developmental abnormalities in invertebrates, as well as in vitro genotoxic effects via oxidative stress (effects identified for different forms of the nanoparticle TiO2, including E171). However, none of these new studies were able to confirm or refute the potential carcinogenesis-promoting effect of E171 reported in the NANOGUT study.
The Agency's recommendations
On completion of this expert appraisal, ANSES emphasised the lack of scientific data able to resolve the uncertainties regarding the safety of the additive E171. It reiterates its recommendations to obtain data for characterising the different physico-chemical forms of E171 and additional toxicological data on the potential effects associated with their ingestion.
Pending a better toxicological characterisation of E171 and the results of work currently under way at European level, ANSES restates its previous general conclusions on nanomaterials aimed at limiting the exposure of workers, consumers and the environment as part of a gradual approach, in particular by promoting safe products that are equivalent in terms of function and effectiveness, and that do not contain nanomaterials.
All this work will be taken into account in the expert appraisal currently being conducted at ANSES on "nanomaterials in food products", which includes all nanomaterials intentionally added to foodstuffs.