Titanium dioxide, once used as the whitening additive E171 in food, has been detected in milk and infant formulas, despite bans on its use in food products in France and the European Union.
In a study published in Science of The Total Environment, researchers from INRAE, AP‑HP, the SOLEIL Synchrotron and CNRS analyzed human milk, animal milk and commercially available infant formulas. Their goal was to measure real-world exposure to titanium dioxide, a nanomaterial still widely used in cosmetics, toothpaste, medications, plastics and other products even after being banned as a food additive.
Titanium dioxide is a white pigment used for decades as a coloring and opacifying agent in products ranging from candy and baked goods to toothpaste and sunscreen. In 2022, the European Union banned its use in food as a precautionary measure due to concerns about its potential health effects, particularly at the nanoparticle level.
In the United States, however, the Food and Drug Administration still allows titanium dioxide in food at levels up to 1% by weight, meaning American consumers may still be eating it in candies, dairy products and other processed foods.
The team used non‑destructive spectrometry to measure titanium levels, identify individual particles and determine their size. Nanoparticles, those smaller than 100 nanometers, are of particular interest because of their unique properties and potential biological impacts.
The findings were striking:
Animal milk (from cows, goats and donkeys, both organic and conventional) contained titanium dioxide nanoparticles in 100% of samples.
Infant formula (stages 1-3, organic and conventional) contained nanoparticles in 83% of samples, with concentrations ranging from 6 million to 3.9 billion particles per liter.
Human milk collected from 10 volunteers near Paris contained titanium dioxide, with levels varying by up to a factor of 15 between individuals, showing that the particles can cross the mammary gland barrier.
“This study shows that infants’ exposure does not end at birth: titanium particles were detected in milk despite the ban on E171 use in food, which suggests contamination through sources other than food,” the authors wrote.
The researchers point to likely environmental and industrial sources, including nanoparticles from air, water, soil and consumer products. Earlier INRAE work also showed that titanium dioxide consumed during pregnancy can cross the placental barrier.
While the study was conducted in France, its implications extend to the United States. Titanium dioxide has not been banned from food in the U.S., where it’s still found in candies, dairy products, salad dressings and other processed foods. For American parents and caregivers, that means infant and maternal exposure may come not only from environmental contamination but also from intentional use in the food supply.
The study’s authors say further research is needed to assess the toxicity of the particles found in milk and to better understand how diet, cosmetics, medications and environmental exposure contribute to these levels.
The research was funded by the French National Research Agency (ANR) and INRAE.