05-25 powdered donut

[Image above] The powdered sugar on top of donuts is one example of the many food products that use titanium dioxide for coloring. The European Food Safety Authority recently revised its guidance to consider use of titanium dioxide as a food additive “unsafe.” Credit: Pixabay

In today’s world, it can be incredibly difficult for the average shopper to assess the nutritional value of their groceries because of all the preservatives and additives included in many foods. Instead of traditional ingredients like “salt” or “yeast,” consumers often find themselves staring at ingredients like “butylated hydroxyanisole 320” or “carrageenan”—words they cannot pronounce much less evaluate for their health impact.

Shoppers can assess some of these additives, such as high fructose corn syrup, thanks to media coverage that brought attention to the esoteric ingredient’s pros and cons. Yet one widely used additive heavily debated in regulatory circles right now—titanium dioxide (TiO2)—remains under the radar for many shoppers.

TiO2 is a white pigment used in a wide variety of products, including paints, paper, textiles, cosmetics, pharmaceuticals, and food. TiO2 is produced in two main forms—a regular pigment-grade form, and an ultrafine nanomaterial form. To date, regulators have generally considered the pigment-grade TiO2 nontoxic while acknowledging the need for more research on the nano form.

TiO2 was first approved for use in food by the United States Food and Drug Administration in 1966 (food additive code INS171), then by the European Union in 1969 (food additive code E171). Specifications guiding use of this additive have undergone minor revisions over the years, but the general consensus that TiO2 is safe for consumption remained firm—until recently.

European Food Safety Authority reassesses E171

*NOTE: Data used for the following assessments come from studies performed on mice, rats, and deceased humans who donated their bodies for research and educational purposes.

In 2016, the European Food Safety Authority (EFSA) published an extensive assessment of TiO2 as a food additive that affirmed the widely held view that E171 “does not raise a genotoxic concern,” i.e., it does not risk damaging an organism’s DNA.

However, the authors noted that the assessment lacked the necessary data to reach a definitive conclusion on the additive’s reproductive toxicity, i.e., possibility to interfere with an organism’s reproductive capabilities. Additionally, the assessment did not include data on nano TiO2 because the existing data “could not be directly applied to the evaluation of the food additive.”

Following this assessment, the EFSA requested the Scientific Committee, a panel of external experts who support the work of EFSA, to undertake a thorough revision of the 2011 guidance on assessing the risk of nanoscience and nanotechnologies in the food and feed chain. The updated guidance published in 2018 specifically included recommendations for considering TiO2 particle size distribution when assessing the safety of E171.

In 2019, both the French Agency for Food, Environment and Occupational Health Safety and the Netherlands Food and Consumer Product Safety Authority published opinions reiterating the lack of scientific data to resolve uncertainties regarding the safety of E171. France subsequently banned use of E171 in food products beginning in January 2020.

In March 2020, the European Commission requested that EFSA provide an updated scientific opinion regarding the safety of E171, taking into account all new relevant data and the 2018 nanotechnology guidance. In March 2021, the EFSA Panel on Food Additives and Flavourings adopted the assessment, and on May 6, it published online.

Like the previous version, the updated assessment lacked the necessary data to reach a definitive conclusion on the additive’s reproductive or developmental toxicity. However, in a stark contrast from the previous version, the updated assessment does not rule out a concern for genotoxicity due to the new data and strengthened analytic methods.

Genotoxicity may lead to cancer, so it is essential to assess the potential genotoxic effect of a substance to make conclusions about its safety. Because the assessment was unable to rule out concern for genotoxicity, “we could not establish a safe level for daily intake of the food additive,” Matthew Wright, a member of the Food Additives and Flavourings panel and chair of EFSA’s working group on E171, says in an EFSA press release.

This assessment does not ban the use of TiO2 in food products. However, the findings will be used by risk managers in the European Commission and Member States to inform their decisions on possible regulatory actions. Considering the European Parliament already called on the European Commission to ban E171 in food products last October, it is highly likely that limitations or bans on TiO2 will occur in the near future—meaning manufacturers of this additive will want to start considering alternative substances.