In a study published in the journal Environmental Toxicology and Pharmacology in 2020, researchers examined the effects of food additives titanium dioxide and silica on the intestinal tract by grouping and feeding mice three different food-grade particles — micro-TiO2, nano-TiO2, and nano-SiO2.  With all three groups, researchers observed changes in the gut microbiota, particularly mucus-associated bacteria. Furthermore, all three groups experienced inflammatory damage to the intestine, but the nano-TiO2 displayed the most pronounced changes. The researchers wrote: “Our results suggest that the toxic effects on the intestine were due to reduced intestinal mucus barrier function and an increase in metabolite lipopolysaccharides which activated the expression of inflammatory factors downstream. In mice exposed to nano-TiO2, the intestinal PKC/TLR4/NF-κB signaling pathway was activated. These findings will raise awareness of toxicities associated with the use of food-grade TiO2 and SiO2.”

Going Public

TiO₂ comes in many different forms. However, only a few of these forms are considered food-grade (acceptable to be added to food). Many studies that raised concern about the safety of TiO₂, including the concern for genotoxicity, used forms of TiO₂ that are not considered acceptable for use in food and have different properties than food-grade TiO₂. Other studies did use food-grade TiO₂, but took steps to break the material down into smaller particles than what would normally be found in food.

Inhaling high concentrations of titanium dioxide dust or fumes, which may occur in occupational settings — such as in the production or processing of products containing the mineral — may cause respiratory problems like coughing, wheezing and shortness of breath, in addition to eye and skin irritation.

We use titanium dioxide as a colourant in some home care products, including in laundry detergents, dishwasher tablets and toilet blocks.

We’re most often exposed to E171 through the foods we ingest. We find E171 in many food products, like popsicles, ice cream, gum, and more. Another way we ingest E171 is through pharmaceutical drugs. Many pills and capsules contain E171 as an inactive ingredient.  

The raw material used in this method is FeSO4. In order to maintain the Fe3 + concentration in the reaction medium in a specific range, reducing agent iron sheet is added in the reaction process. Iron yellow crystal seed was added and air was introduced to synthesize iron yellow under certain pH conditions. The method mainly includes two steps: (1) firstly, FeSO4 · 7H2O is used as raw material, NaOH or NH3 · H2O is used as precipitant or pH regulator, and air is used as oxidant to prepare crystal seed; (2) Iron yellow is produced by two-step oxidation with crystal seed, FeSO4, iron sheet and air.

Lithopone: an alternative to titanium dioxide

Overall, the use of titanium dioxide by manufacturers is essential for various industries, providing valuable properties and benefits for a wide range of products. As technology advances and new applications are discovered, the demand for titanium dioxide is expected to continue to grow. Manufacturers will need to adapt and innovate to meet the evolving needs of their customers while ensuring the safety and sustainability of their products.

However, most dermatologists will warn their patients not to rely on mineral makeup alone in order to be protected by the sun’s rays. This is because there can be quite a bit of variation with mineral foundation – not only with how much we apply but how much titanium dioxide the foundation contains.