The committee could not finalize the assessment of some other flavoring agents, requiring further information. JECFA highlighted the importance of receiving complete data submissions from the sponsors for conducting the safety evaluation.

Since then, there has been a few animal studies suggesting titanium dioxide is connected to cancer. A 2017 study in Scientific Reports, for instance, found that rats with titanium dioxide in their diet had impaired immune systems, which could contribute to autoimmune diseases and colorectal cancer.

The European Commission banned titanium dioxide as a food additive in the EU in 2022 after the European Food Safety Authority (EFSA) conducted an updated safety assessment of E171 and concluded the panel could not eliminate concerns about its genotoxicity. 

In general, nanoparticles have been shown to accumulate in the body, particularly in organs in the gastrointestinal tract, along with the liver, spleen, and capillaries of the lungs.