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.

The assessment was conducted following a rigorous methodology and taking into consideration many thousands of studies that have become available since EFSA’s previous assessment in 2016, including new scientific evidence and data on nanoparticles. 

The production of Chinese anatase titanium dioxide involves a series of complex chemical processes, including hydrolysis and calcination of titanium precursors. These processes result in the formation of nanoscale particles of anatase titanium dioxide, which exhibit enhanced properties such as increased surface area and improved reactivity. The size and morphology of these nanoparticles can be controlled during the synthesis process, allowing for the production of tailored materials with specific properties for different applications.

What Is Titanium Dioxide?

A 2012 study published in the journal Environmental Science & Technology noted that children are especially exposed to titanium dioxide because of the food that contains the food additive and is particularly marketed to children, including candy and cakes.

Titanium dioxide is a food additive that can be found in over 3,000 different products in EWG’s Food Scores database.

A  2023 study published in the journal Environmental Research, scientists examined the effect of titanium dioxide nanoparticles on important gut bacteria in mice. Their results showed “the growth inhibitory effects could be associated with cell membrane damage caused by titanium dioxide nanoparticles to the bacterial strains. Metabolomics analysis showed that TiO2 NPs caused alterations in multiple metabolic pathways of gut bacteria, such as tryptophan and arginine metabolism, which were demonstrated to play crucial roles in regulating gut and host health.” The researchers also found that four different neuroprotective metabolites “were significantly reduced” in urine and in vitro bacteria and vivo urine samples. The researchers concluded: “Increasing evidence implies that the gut microbiome plays a profound role in regulating host metabolism. Our results illustrated that TiO2 NPs hindered the growth of four beneficial gut bacterial strains.”

The FDA has not updated its general guidance on safety assessments since 2007. Within that time, there has been a significant increase in research on the confluence of toxicology, nanotechnology and human health. The EU updates its guidance regularly with new science available to offer proper safety assessments, with its most recent update published in 2021.

In a 2020 study published in the Journal of Trace Elements in Medicine and Biology, researchers conducted an in vitro experiment to analyze the effects of TiO2 nanoparticles on a human neuroblastoma (SH-SY5Y) cell line. The scientists evaluated “reactive oxygen species (ROS) generation, apoptosis, cellular antioxidant response, endoplasmic reticulum stress and autophagy.” The results showed that exposure to the nanoparticles “induced ROS generation in a dose dependent manner, with values reaching up to 10 fold those of controls. Nrf2 nuclear localization and autophagy also increased in a dose dependent manner. Apoptosis increased by 4- to 10-fold compared to the control group, depending on the dose employed.”