The main food categories contributing to dietary exposure of E171 are fine bakery wares, soups, broths and sauces (for infants, toddlers and adolescents); and soups, broths, sauces, salads and savoury based sandwich spreads (for children, adults and the elderly). Processed nuts are also a main contributing food category for adults and the elderly.
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.”
Australia and New Zealand review of TiO2

Respiratory Exposure
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.”
History[edit]
Barium sulphate, a chemical compound with the formula BaSO₄, is widely recognized for its numerous applications in various industries, particularly in the field of medicine, paints, plastics, and as a component in drilling fluids. One of the distinguishing features of barium sulphate is its striking physical property its color. Understanding the color of barium sulphate not only helps in identifying the compound during handling but also plays a significant role in its applications and quality assessment.
It’s particularly useful in sunscreen as it has impressive UV resistance and helps block the sun’s UVA and UVB rays from reaching your skin (6Trusted Source).
Titanium dioxide remains in many food products in this country because of regulatory folly by the Food and Drug Administration, which allows problematic food ingredients to remain undetected and unreviewed.