Titanium dioxide is a versatile material with a wide range of applications. Some of its most common uses include:

We've used titanium dioxide safely for decades. However, recently its safety was called into question. 
 
At CRIS, we've explored the safety of titanium dioxide for nearly half a decade, including conducting double-blind research to test the safety of food-grade titanium dioxide (E171). Our study shows that when exposed to food-grade titanium dioxide in normal conditions, research animals did not experience adverse health outcomes.
 
It's important to emphasize that in a National Institutes of Health study, experimental animals were exposed to titanium dioxide in amounts as high as 5% of their diet for a lifetime and showed no evidence of adverse effects. 
 
A handful of studies greatly influenced the decisions made by the European Food Safety Authority (EFSA). Unfortunately, these studies did not consider that titanium dioxide exposure comes from food, not drinking water. Additionally, CRIS researchers could not reproduce the adverse outcomes identified by the studies through typical food ingestion. Regardless, the EFSA banned E171 as a food ingredient and for use in other capacities in the summer of 2022.
 
In 2022, the United States, United Kingdom, and Canada maintained that the scientific evidence supports that titanium dioxide (E171) is safe for humans to use and consume.

Research supports that applying titanium dioxide to the skin in the form of sunscreens, makeup, and other topical products does not pose any health risks. 

While loose titanium dioxide presents a problem, titanium dioxide within sunscreen formulations presents a much safer option than conventional sunscreen chemicals like oxybenzone and octinoxate. However, titanium dioxide may become dangerous when it is nanoparticle size. Generally, nanoparticles can be 1000 times smaller than the width of a human hair. Despite nanoparticles becoming increasingly common across industries, they have not been properly assessed for human or environmental health effects, nor are they adequately regulated. Researchers don’t quite understand the impacts nanoparticles could have on human health and the environment. However, because of their infinitesimally small size, nanoparticles may be more chemically reactive and therefore more bioavailable, and may behave differently than larger particles of the same substance; these characteristics may lead to potential damage in the human body or ecosystem.