The dangers of a broken mercury thermometer include the possibility of mercury poisoning, and other injuries can be caused by shards of glass. Mercury is metal mercury, it is a volatile and highly toxic substances, mercury thermometer broken, the thermometer will flow out of the mercury, room temperature is easy to volatile mercury vapor, if not handled properly, can enter the human body through the respiratory tract, the mercury concentration reaches a certain level can lead to human mercury poisoning. Mercury thermometer broken glass fragments, such as not paying attention may cause skin scratches or injuries. At the same time, mercury can also enter the body through the skin, reaching a certain dose can also cause mercury poisoning, damage to the central nervous system, lungs and reproductive system.