Food additive E171 (TITANIUM DIOXIDE): A « sweet » danger and the precautionary principle, par Alessandra Donati


What is E171?

E171 (titanium dioxide) is a widespread food additive mainly used as whitening and brightening agent in cheeses, sauces, skimmed milk, ice cream, confectionery products, sweets, candies, chewing gum, pastries, and cookies. It can also be found in cosmetics and medications. It is labeled as TiO2 or E171.

How is E171 regulated under EU law?

As a food additive, E171 falls within the scope of Regulation n° 1333/2008. According to this Regulation (article 4), only food additives which are included in the lists set forth by such Regulation may be placed on the market. Under article 6, a food additive may be included in such lists if:

  • It does not pose a safety concern to the health of the consumer at the level of use proposed;
  • There is a reasonable technological need that cannot be achieved by other economically and technologically practicable means;
  • Its use does not mislead the consumer.

Is there any risk associated with the use of E171?

By 45% of its size distribution, E171 is composed of nanoparticles which may pass through protective walls of organs such as the liver, lungs, or intestines, by causing risks to human health.  The possible risk to health after consuming food containing nanoparticles has been poorly explored, but it is supposed that the toxicity of nanoparticles depends on their size, morphology, rate of migration, and amount consumed. According to the 2009 report of the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) which advises the European Commission, even though nanomaterials are not per se dangerous, there still is scientific uncertainty about the safety of nanomaterials in many aspects and therefore their safety assessment must be done on a case-by-case basis.

Despite its size distribution, according to the existing definition of nanomaterial (adopted in 2011 and today under review), E171 cannot correctly be qualified as a nanomaterial since the percentage of nanoparticles is lower, by only 5%, than the required threshold of 50% of its nanoparticles size.

Therefore, the regulations adopted under EU law to mitigate the potential negative effects of nanomaterials do not apply to E171. By way of example, E171 is not subject to a labeling obligation according to article 18 of the Regulation n° 1169/2011, under which “all ingredients present in the form of engineered nanomaterials shall be clearly indicated in the list of ingredients”. Moreover, although E171contains nanoparticles, it shall not go through a separate and more specific authorization procedure before being placed in the market, but shall be assessed only as any other food additive which does not contain any nanoparticles (Article 12 of the Regulation n° 1333/2008).

What is the controversy about E 171?

E171 is at the core of an intense scientific and political controversy.

In 2006, the International Agency for Research on Cancer (IARC) classified E171 as a potential carcinogenic factor based on mechanisms and tests involving animals regarding exposure by inhalation. In 2016, the European Food Safety Authority (EFSA) found that data concerning values and exposure of humans to E171 by way of food consumption do not raise concerns. However, with regard to the insufficiency of research data, the admissible daily intake of E171 was not determined. In 2017, the French Institut National de la Recherche Agronomique (INRA) pointed out that chronical exposition of rats to E171, by way of consumption of such food additive, may cause pre-cancer lesions. Nevertheless, the effects on humans remain uncertain. In its report as of April 2017, the French Authority for health and food safety (ANSES) underlined that, if the results of INRA’s analysis do not entirely undermine the safety assessment made by EFSA, they show yet the necessity to carry out new researches to understand the potential carcinogenic effects of such food additive.

As a response to the scientific controversy surrounding the carcinogenic effect of E171, some producers and distributors of food products (e.g., Carambar, Haribo, Mars, Picard, William Saurin, Carrefour, Super U, Leclerc) voluntarily undertook to suspend the use of E171. Moreover, in October 2018, the French Parliament decided for the temporary suspension of the placing on the market of E171 (article 53 LOI n° 2018-938 as of 30 October 2018). The decision of the French Parliament was effectively implemented in April 2019 when the French Government decided, based on the precautionary principle, to ban E171 from any food product starting from January 1st, 2020 and for one year. Pending the decision of the European Commission that shall evaluate a potential ban of E171 at EU level, EFSA has confirmed on May 13, 2019 that “ANSES opinion published in April 2019 does not identify any major new findings that would overrule the conclusions made in the previous scientific opinions on the safety of titanium dioxide (E171) as a food additive issued by the EFSA Panel”. Therefore, EFSA confirmed that E171 used as a food additive is not carcinogenic after oral administration.


The E171 case epitomizes the importance and the complexity of the precautionary principle which, as a “borderline” principle stands at the frontier between science and politics at European and national level with regard to public as well as private decision-makers.

A scientific principle

First of all, the precautionary principle is a “scientific principle”. As consistently underlined by the European Court of Justice, the application of the precautionary principle requires the carry out by scientific experts of a scientific assessment of the uncertain risk at stake (CJCE 23 September 2003, Commission/Kingdom of Denmark, C-192/01, Rec. I-9693, 48 ; CJCE 5 February 2004, Commission/French Republic, C-24/00, Rec. I-1277, 55). The precautionary principle shall be applied in a situation where science is unable to provide decision-makers with concluding evidence about the existence or the extent of a risk for the environment or public health. The existence of scientific uncertainty may be linked, as the E171 case shows, to the diverging opinions expressed by different scientific bodies as to the potential consequences of the exposure to a certain product or substance. Due to the different advises formulated by IARC, EFSA, INRA and the ANSES, political decision-makers are not in the position to assess with certainty the carcinogenic effect resulting from the consumption of E171 as a food additive.

A political principle

Scientific, the precautionary principle is also a political principle. Indeed, it is applied by political decision-makers entrusted with the duty of protecting public health and the environment against uncertain risks. As shown by the E171 case, the different political “levels of regulation” and “actors of implementation” may overlap.

As to the levels of regulation, the precautionary principle is not only provided by article 191 § 2 TFUE and by several EU directives and regulations, but it is also enshrined in the national laws of several EU Member States (in France, article 110-1 Code de l’environnement and article 5 Charte de l’environnement). Some mechanisms of dialogue between the European and the national level are expressly provided for. With regard to E171, its authorization is provided at EU level, according to Regulation n° 1333/2008. The procedure for obtaining the authorization of such food additive may be started either on the initiative of the Commission or following an application made by a Member State or by any interested party. When delivering the authorization, the EU Commission should take into account the precautionary principle (Recital 7 of Regulation n° 1333/2008). Once the food additive has been authorized, if a Member States considers that it is likely to constitute a serious risk to human health, animal health or the environment, it may adopt, on the basis of the precautionary principle, a safeguard measure limiting or restricting the use of such food additive in its territory. In this regard, the temporary ban adopted by France as to the use of E171 in food additives shall be interpreted as a safeguard measures implemented on the basis of article 54 of Regulation n° 178/2002, enabling Member States to implement protective measures aiming at managing a serious risk to public health.

As to the actors who may implement the precautionary principle, a distinction shall be made between public and private decision-makers. Traditionally, the precautionary principle has been applied by public decision-makers (EU institutions and competent authorities of the Member States). However, as showed by the E171 case, even private decision-makers (and especially business operators) may be concerned by the application of this principle. First of all, business operators may adopt a precautionary measure voluntarily. In the case of E171, even before the adoption by public decision-makers (the French Parliament and Government) of a ban of such additive, some business operators voluntarily decided to suspend its use.

Furthermore, with regard to food business operators, some specific obligations enshrined in the EU legal texts seem to be inspired by a precautionary approach. By way of example, according to article 5 of Regulation n° 1333/2008, business operators shall not place on the market a food additive if its use does not comply with this Regulation. Considering that the regulation is based on the precautionary principle, one may argue that, at least indirectly, business operators are bound to respect the precautionary principle. Indeed, as provided for by Recital 7 of the Regulation n° 178/2002, “a food business operator is best placed to devise a safe system for ensuring that the food is safe; thus, it should have primary legal responsibility for ensuring food safety”. Consequently, if a food business operator considers or has reason to believe that food is not in compliance with the food safety requirements, it shall immediately initiate procedures to withdraw the food and it shall inform the competent authorities (Articles 17 and 19 Regulation n° 178/2002).


As it was the case for pesticides and endocrine disruptors, the E171 saga brings back the precautionary principle at the hearth of the scientific, political and legal debate on the management of risks to public health. Once again, in a context of scientific uncertainty and diverging scientific opinion, the EU Commission shall decide, in the next few months, whether or not to suspend for the entire EU territory the authorization of such food additive. We will see if, unlike the pesticides and endocrine disruptors cases, the EU Commission will make use of the precautionary principle to adopt the measure that allows for the best possible protection of public health.

Alessandra Donati,Research fellow at the Max Planck Institute in Luxembourg, Avvocato all’Ordine di Milano, Avocate au Barreau de Paris et Doctorante à l’Université Paris 1 Sorbonne. Son sujet de thèse est « Le principe de précaution en droit de l’Union européenne ».

Re(lire) les autres posts d’Alessandra ici

3 réflexions sur “Food additive E171 (TITANIUM DIOXIDE): A « sweet » danger and the precautionary principle, par Alessandra Donati

  1. E171 or TiO2 is used mainly to whiten or intensify the brilliancy of edible foods.

    Honestly, if that is the only use of E171, there should be no reason to use it, really… The amount of talk wasted around the precautionary principle seems almost pointless.

    As stated in the article, under article 6, on of the criterion required for autorisation is that there should be a reasonable technological need that cannot be achieved by other economically and technologically practicable means.

    Well, that’s should be the crux of the argument: the « reasonable technological need » is an irrational whim. Not even a need.


  2. Dear reader,

    Thank you for your interest and your comment. Please find below some points of reflection.

    From a scientific point of view, I am not in the position to assess if E171 is only used as a whitening and brightening agent. What it results from scientific literature, is that it is mainly used as a whitening and brightening agent.

    From a legal perspective, a food additive is defined under Regulation 1333/2008 as “any substance not normally consumed as a food in itself and not normally used as a characteristic ingredient of food, whether or not it has nutritive value, the intentional addition of which to food for a technological purpose in the manufacture, processing, preparation, treatment, packaging, transport or storage of such food results, or may be reasonably expected to result, in it or its by-products becoming directly or indirectly a component of such foods”. The authorised technological needs/functions are set forth in Annex 3 of this Regulation and they include the technological functions pursued by E171 (in this case, especially a colouring function).

    This means that, from a legal perspective, assuming that E171 has a reasonable technological need/function, the question is whether or not decision-makers shall permit the use of such food additive knowing that there are scientific uncertainties as to its carcinogenic effect for humans. Because there is a risk and a scientific uncertainty (as explained in the blogpost), the precautionary principle shall be applied for the purpose of protecting public health.

    I hope these clarifications are useful for you.

    Please feel free to contact me for any further comment.

    Best regards,

    Alessandra Donati


    1. I understand what you describe as the « legal perspective ». I’m more concerned on the level of a « political perspective » or a « moral perspective ».

      By that, I mean the following: I’m very concerned by the « debate » currently happening over the precautionary principle opposing « rationalists » and « lobbies » to « ecologists » of various kinds. The tendency I see is that this « debate » over the precautionary principle is becoming incredibly tense, and that « ecologists » (for lack of a better word) try to pigeonhole their various concerns by instrumentalising claims of scientific uncertainty to forbid substances which they disagree of or fear. Broadly speaking.

      And I’m very concerned by these kinds of « attacks on science ». It seems to me that most of these attacks are done because there aren’t any other real way to oppose various substances on the grounds of their social benefit.

      We’re talking here of E171 or TiO2. But there are other substances (too controversial to mention publicly…) where their social usefulness can be cast into doubt but where « rationalists » would claim that there are no scientific concerns when it comes to safety.

      In this situation, political opposition to these substances is bound to take the form of « attacks on science ». And that worries me very very very much.

      In order to avoid this situation, which is becoming utter madness, I believe we should add additional clauses taking into account other factors than mere « safety ». Such as the real usefulness of E171 or TiO2… (Whitening, brilliancy? Seriously…)

      The debate on substances would take a perhaps more political and less legalistic turn, introducing uncertainty for industrials, no doubt, but if it’s the price to pay to get the debate concerning « attacks on science » to cool down, I’d be quite willing to pay that price.

      And if such an additional social requirement comes into force, it might then be a good idea to replace the notion of « danger » in the precautionary principle by a notion of « risk ». Risk is quantifiable. Danger is a much more subjective concept and prone to more manipulations of science than should be allowed, in my opinion.

      And an evidence-based retrospective control mechanism would also be useful: We should assess retrospectively whether we make right decisions or not when authorizing or not a given substance, in order to implement evidence-based corrective legislative mechanisms. The following read might be useful when trying to imagine what such a corrective mechanism could be:

      My opinion in a nutshell: we should move beyond instrumentalised toxicology. It’s becoming revolting. Really.


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