Titanium is not toxic, even in large doses, and does not have any natural effects on the human body.
Powdered titanium and planed titanium flakes can easily cause fires and explode when heated in the air. Water and carbon dioxide-based fire extinguishing methods are ineffective against burning titanium; Class D dry powder fire extinguishing agents must be used instead.
When producing or handling chlorine, care must be taken that grade 5 titanium round bar should only be used where there is no dry chlorine around, otherwise it will cause a titanium/chlorine fire. Even wet chlorine is a fire hazard because it can dry out unexpectedly under unusual weather conditions.
A fresh, unoxidized surface of titanium may catch fire when it comes in contact with liquid oxygen. This surface can be formed by the collision of an oxidized titanium surface with a hard object, or within a crack caused by a mechanical strain. Therefore, the use of titanium in liquid oxygen systems is likely to be limited, such as in the aerospace industry.