Titanium dioxide is used a food colour (E171) and, as with all food colours, its technological function is to make food more visually appealing, to give colour to food that would otherwise be colourless, or to restore the original appearance of food. Titanium dioxide is also present in cosmetics, paints, and medicines.

Background

Titanium dioxide, or TiO2, will be listed on product labels, but companies are not required to list ingredient size or structure. When it is used in sunscreens to block UV light, titanium dioxide is considered an active ingredient, which means the concentration must also be listed.

French researchers studied how and where E171 nanoparticles enter the bloodstream, first studying the route through pigs and then in vitro with human buccal cells, for a 2023 study published in the journal Nanotoxicology. The research showed that the nanoparticles absorbed quickly through the mouth and then into the bloodstream, before damaging DNA and hindering cell regeneration.

Reason for listing: CNNC Huayuan Titanium Dioxide Co., Ltd., a well-known brand of titanium dioxide factory, started in 1989, specializing in the research and development, production, sales and service of titanium dioxide products. One of the titanium dioxide enterprises producing more than 10,000 tons.

Another important application of titanium dioxide is in the production of sunscreen and other skincare products. Titanium dioxide is a key ingredient in many sunscreens due to its ability to reflect and scatter ultraviolet (UV) radiation, providing protection against harmful UV rays. Manufacturers of titanium dioxide for sunscreen products often use special coatings and surface treatments to enhance its UV-blocking properties.

Chloride process. This process requires a high titanium feedstock. Rutile is reacted with hydrochloric acid to produce titanium tetrachloride, which can be hydrolyzed with steam or oxidized with air to render the dioxide. A rutile form of titanium dioxide is obtained.

The additives that received a “no safety concern” conclusion based on current estimated dietary exposure are as follows:

Testing samples were made mixing 100 uL of TiO₂NPs suspensions (0.2 mg/mL and 0.02 mg/mL) and vitamins@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) with 100 μL ATCC 29,213 methicillin-sensitive Staphylococcus aureus (MSSA) (10⁷ in PBS, pH 7). Controls were made replacing nanoparticles with the same volume of PBS. The concentrations of nanoparticle suspensions were chosen based on the FDA approved maximal and the minimal amount usually found in sunscreens, which are 20% and 2% (this is equivalent to 0.2 mg/mL and 0.02 mg/mL for nanoparticles suspensions). The cream concentration, on the other hand, was an intermediate value of 10%.