According to the Cosmetics Database, Titanium Dioxide is considered a low to moderate hazard ingredient, depending on use. The EWG notes concerns regarding cancer, allergic reactions, biochemical and cellular changes, organ system toxicity and irritation. Titanium Dioxide can produce "excess reactive oxygen species that can interfere with cellular signaling, cause mutations, lead to cell death and may be implicated in cardiovascular disease." Animal studies showed that very low doses were able to cause respiratory and cardiovascular effects, and this ingredient has been classified as "expected to be toxic or harmful" and as a medium health priority.