Even the relatively small amount of mercury in a glass thermometer is enough to create dangerous fumes and contaminate the atmosphere. The safest way to deal with a broken mercury thermometer is to clean up the mercury immediately, and then safely dispose of anything that the mercury touched. Mercury isn't difficult to clean up on smooth surfaces such as wood, tile or linoleum, but becomes more complicated if the thermometer breaks over carpet or other fabric surfaces.
Ask everyone to step away from the area around the broken thermometer immediately. Remove children and pets from the room. Don't allow anybody to step on the mercury or the shards of glass.
Open any doors or windows to provide fresh air. Put on a pair of rubber or latex gloves before you clean up the broken thermometer.
Pick up large pieces of glass. Place the broken glass on a layer of paper towels, then fold the paper towels carefully around the glass. Place the glass in a labelled zip-seal bag.
Use two pieces of cardboard to sweep up large beads of mercury. Work slowly to prevent the large mercury beads from breaking up into smaller beads.
Use a piece of duct tape or packing tape to pick up small mercury beads. If the room isn't brightly lit, use a bright flashlight to help you locate all of the small mercury beads. Place the tape and the small beads in a labelled zip-seal bag. Seal the bag. Place the zip-seal bags, and your gloves, into a larger plastic bag.
Use a carpet knife to cut away the carpet if the thermometer broke over carpet. Treat upholstery the same way. Cut away only the area of the spill, then place the carpet or upholstery material in a tightly sealed plastic bag. If the thermometer broke over fabric, seal the fabric in a bag and discard it.
Keep the windows open for at least 24 hours after the completing the cleanup. Don't allow children or pets to enter the area for at least 24 hours.
Call your local hazardous waste centre or your area health department and ask how to dispose of the bag of contaminated materials.
Never clean up mercury with a vacuum cleaner because the vacuum cleaner will distribute the mercury fumes into the air. Never clean up mercury with a broom because the broom will divide the mercury into smaller beads, then will spread the small beads. Never dispose of mercury down a drain. Discard any clothing that comes in contact with the mercury. Don't attempt to launder the clothing, as the mercury will contaminate your washing machine and plumbing system. Discard your shoes if you step in mercury. Place contaminated garments or shoes in a tightly sealed plastic bag.