text: Metallic mercury is not very hazardous.  However, it gives off mercury vapor and long exposure to it is harmful.  You should do your best to clean up the mercury, but the amount in a single thermometer is not worrisome.\n\nUse steel wool to absorb the mercury.  Wrap it in several layers of plastic or newspaper and dispose of it with your household trash.  Although mercury is hazardous waste, household hazardous waste is exempt from regulation.