This regulation entered into force on 7 February 2022. However, the Regulation included a six-month transitional period to allow food businesses time to phase out the use of this food additive and to reformulate their products using suitable alternatives. This period will end on 7 August 2022.

A study published in the Journal of Agricultural and Food Chemistry in 2019 sought to examine the effects of titanium dioxide on intestinal inflammation. Researchers did this by feeding rats titanium dioxide nanoparticles and found that, after the course of two to three months, the animals had lower body weights and induced intestinal inflammation. The researchers also found the nanoparticles altered gut microbiota composition and aggravated chronic colitis. The rats also experienced reduced populations of CD4+T cells (which are cells that help organize immune responses by prompting other immune cells to fight infection), regulatory T cells, and white blood cells in mesenteric lymph nodes. The researchers wrote: “Dietary TiO2 nanoparticles could interfere with the balance of the immune system and dynamic of gut microbiome, which may result in low-grade intestinal inflammation and aggravated immunological response to external stimulus, thus introducing potential health risk.”

Health Canada's Food Directorate recently completed a “state of the science” report on titanium dioxide (TiO₂) as a food additive. Food-grade TiO₂ is a white powder made up of small particles that has been permitted in Canada and internationally for many years as a food additive to whiten or brighten foods. Food-grade TiO₂ has long been considered safe in Canada and in other countries when eaten as part of the diet.