Other food products that list titanium dioxide are Lucerne cottage cheese, Beyond Meat's chicken plant-based tenders, Great Value ice cream and Chips Ahoy! cookies.

3. What is EFSA saying in its 2021 opinion on the safety of titanium dioxide as a food additive?

What's the Verdict?

Promotion of obesity-related metabolic disorders

One of the main uses of TiO2 powder is as a pigment in paints and coatings. It is valued for its excellent opacity, brightness, and UV resistance, making it ideal for use in exterior paints, industrial coatings, and automotive finishes. TiO2 powder suppliers work closely with paint manufacturers to supply them with the right grade and quantity of TiO2 powder to meet their specific requirements.

It's also used in sunscreens as a UV filtering ingredient, helping to protect a person's skin by blocking absorption the ultraviolet light that can cause sunburn and cancer.

In its 2016 opinion, the ANS Panel recommended new studies be carried out to fill the gaps on possible effects on the reproductive system, which could enable them to set an Acceptable Daily Intake (ADI ). Uncertainty around the characterisation of the material used as the food additive (E 171) was also highlighted, in particular with respect to particle size and particle size distribution of titanium dioxide used as E 171.   

Magnesium occurs in seawater and in ores such as dolomite (CaCO ₃ MgCO ₃), magnesite (MgCO ₃), and carnallite (MgCl ₂ KCl 6H ₂O).

For a review published in 2023 in the journal Environmental Pollution, researchers examined E171 as a possible factor promoting obesity-related metabolic disorders. Because gut microbiota play an important role in immune function maintenance and development, and because titanium dioxide as a food additive has been shown to alter gut microbiota, researchers wanted to review “the dysregulations along the gut microbiota-immune system axis after oral TiO2 exposure compared to those reported in obese or diabetic patients, and to highlight potential mechanisms by which foodborne TiO2 nanoparticles may increase the susceptibility to develop obesity-related metabolic disorders.” The study authors discovered recurrent changes in the gut microbiota composition when exposed to titanium dioxide nanoparticles, with an imbalance of intestinal symbiotic microbiota. These changes and imbalances were also reported and played a role in the development of obesity, the authors wrote. This highlights “foodborne TiO2 nanoparticles as an endocrine disruptor-like chemical promoting obesity-related disorders,” the authors concluded.

Rebecca Capua is an assistant conservator in the Paper Conservation Department at the Metropolitan Museum of Art since 2009. She received an MA in art history and an Advanced Certificate in art conservation from the Conservation Center, Institute of Fine Arts, New York University in 2007. Her primary area of research is on the materials of American artists of the late 19th and early 20th century. Address: The Sherman Fairchild Center for the Conservation of Works on Paper, Metropolitan Museum of Art, 1000 Fifth Avenue, New York, NY 10028. Email: rebecca.capua@metmuseum.org.

Since then, there has been a few animal studies suggesting titanium dioxide is connected to cancer. A 2017 study in Scientific Reports, for instance, found that rats with titanium dioxide in their diet had impaired immune systems, which could contribute to autoimmune diseases and colorectal cancer.

In order to contribute with experimental evidence that could help to achieve a better understanding of the field for future regulation, in the present work, the biocompatibility of commercial P25TiO₂NPs (one type of TiO₂NPs used in sunscreen formulations) and two novel functionalized P25TiO₂NPs were evaluated under solar simulated irradiation. White light, generated by red, blue, and yellow LEDs, together with UV ones, was chosen to simulate the solar spectra. Functionalization of TiO₂NPs was made with antioxidant vitamins in order to prevent the expected photo-initiated ROS production when nanoparticles are exposed to the simulated solar spectra. Vitamin B2 (riboflavin) and vitamin C were chosen to carry out the functionalization because they are water-soluble, low-cost, and are a constitutive part of biological processes. In addition, it is known that both have the potential to prevent macromolecular oxidation by ROS [23], [24], [25], [26].

3. UV Protection Tires are constantly exposed to harsh environmental conditions, including ultraviolet (UV) rays from the sun. Titanium dioxide provides excellent UV protection, minimizing degradation caused by prolonged exposure. This property ensures that tires maintain their integrity and performance over time, leading to a longer lifespan.

Alterations in gut microbiota

This work confirms previous studies that show P-25 and other untreated anatase 377 nanoparticles should not be employed in sunscreens because the toxicity of P25TiO2NPs under UV radiation is significant.