> In 2021, the European Food Safety Authority (EFSA) ruled that as a consequence of new understandings of nanoparticles, titanium dioxide could "no longer be considered safe as a food additive",
Taken at face value that quote seems like reason enough to at least suspect that there's a possible problem. It also says that by the time they did that France had already banned it.
The fact that a bunch of people evaluated evidence that gave them significant concern doesn't prove that they're right, but it is some reason to believe it's toxic... It's not a lot very strong thing to base that belief on, but it's something. Reading that alone I would try to avoid the stuff until I got the chance to look into what all that evidence was.
That's assuming the article can be taken at face value. This is wikipedia after all. I did notice that there was a prominent statement right at the top of the "Health and Safety" section which says it "is regarded as "completely nontoxic". Maybe that is true, but the citation points to a source from 2006 while the EU decided to ban it 15 years later after "new understandings of nanoparticles".
