What titanium dioxide is really emblematic of ... is the failure of FDA to look back at these old decisions and ask whether its decisions that were made in this case ... 56 years ago (in the 1966 approval) still hold up, he said.

According to a 2011 study published in Radiology and Oncology, titanium dioxide may lead to some adverse effects in the body, including oxidative stress, inflammation, and changes in cell signaling pathways. Additionally, pure titanium dioxide can be notably harmful when inhaled.