Titanium dioxide as used in sunscreens is commonly modified with other ingredients to ensure efficacy and stability. Examples of what are known as surface modifier ingredients used for titanium dioxide include stearic acid, isostearic acid, polyhydroxystearic acid, and dimethicone/methicone copolymer.

Titanium dioxide comes in the form of a white powder and is sometimes used in cosmetics to adjust a color to a lighter shade. This is also why it can produce a white cast.

A few non-dietary studies have reported adverse effects in the gastrointestinal tract of laboratory animals given food-grade TiO₂. However, these same effects were not seen when the same or higher doses of food-grade TiO₂ were administered in the animals' diet. Dietary studies best reflect how humans are exposed to TiO₂ from food. Thus, the Food Directorate placed the most emphasis on the results of these studies in the state of the science report.

Titanium dioxide (TiO2) is a chemically inert inorganic compound and an insoluble white solid that occurs naturally in several minerals, including rutile, anatase, and brookite. It is created synthetically from the mineral ilmenite. It is an insoluble white solid. Anatase, when compared to brookite and routine, has the most industrial applications, but it is the most toxic form of TiO2.

Furthermore, the factory's investment in research and development allows it to stay ahead of the curve in terms of innovation. By continuously exploring new possibilities and improving its processes, CAS 13463-67-7 is able to offer cutting-edge titanium dioxide products that meet the evolving needs of the market.

Other experts say there is simply no conclusive evidence at this point that titanium dioxide is damaging to humans after ingesting. Kaminski in particular said the research studies cite health hazards that were found by using high doses of the product, which you would not normally see in food.

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.”

In food products, E171 is not a singular ingredient; it’s always combined with other ingredients (e.g., proteins and fats) in the food product. Digesting food is a slow process for the body compared to drinking a beverage, which passes much faster through the body. 

Furthermore, the use of titanium dioxide in rubber helps to reduce the environmental impact of rubber manufacturing processes. As a non-toxic and environmentally friendly material, titanium dioxide is safe for use in rubber products that come into contact with food, water, or other sensitive materials. This makes it an attractive choice for manufacturers looking to produce eco-friendly and sustainable rubber goods.

The trend in the production of NPs is likely to lead to increasing amounts of nano-powders in the air, water and soil, which will consequently affect living organisms. Labielle et al. demonstrated that 25 % of Al(OH)₃-coated TiO₂ particles from sunscreens are dispersed as a stable colloid and become available to microorganisms and filter-feeders, while the remaining 75 % are probably incorporated into geogenic sediments, where they could become available to benthic fauna. Solar UV iradiation may penetrate as far as 20 m in the water column  and therefore photo-activate the dispersed particles, which may have an adverse effect on various aquatic organisms.

Physical and Chemical Properties

In a study published in the journal Food and Chemical Toxicology in 2016, researchers investigated whether titanium dioxide exposure led to an increase in colorectal tumor creation in mice by using a colitis associated cancer model. By measuring tumor progression markers, the researchers found that mice given titanium dioxide experienced enhanced tumor formation in the distal colon.  There was also a decrease of cells that act as a protective barrier in the colon. The researchers wrote: “These results suggest that E171 could worsen pre-existent intestinal diseases.”

Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant may be used, such as a small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.

Lithopone B311 Datasheet