Declaration of Competing Interest

Yes. According to the FDA and other regulatory agencies globally, “titanium dioxide may be safely used for coloring foods”. Titanium dioxide is safe to use, and the FDA provides strict guidance on how much can be used in food. The amount of food-grade titanium dioxide that is used is extremely small; the FDA has set a limit of 1 percent titanium dioxide for food. There is currently no indication of a health risk at this level of exposure through the diet.

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.