Public Health

What should I do when a mercury-containing glass thermometer is broken?

Because of concerns for mercury, many manufacturers and retailers of thermometers have stopped producing and selling mercury-containing glass thermometers.  However, some older glass thermometers in homes, businesses, or schools may contain mercury.  When these thermometers break, there will be some broken glass and small amounts of mercury may sometimes be released.  The released liquid mercury will appear as small, bright or glimmering, silver-colored beads, droplets, or balls.  Children and pets sometimes are attracted to these bright shiny beads or droplets and want to touch them.  But it is very important that they do not do so, because mercury can be absorbed by contact with skin or through accidental ingestion, such as can occur from hand to mouth contact of young children.  Therefore, CHILDREN AND PETS ARE ADVISED TO STAY AWAY FROM THE AREA UNTIL MERCURY CLEANUP AND DISPOSAL IS COMPLETE AND ANY BROKEN GLASS OR LIQUID MERCURY BEADS OR DROPLETS ARE REMOVED FROM THE AREA. 

  • IT IS RECOMMENDED THAT MOST FAMILIES NOT TRY TO CLEAN UP ANY MERCURY SPILL THAT IS MORE THAN THE CONTENTS OF A SINGLE THERMOMETER.  IF MORE MERCURY IS RELEASED THAN FROM A SINGLE THERMOMETER, CALL YOUR LOCAL HEALTH DEPARTMENT OR MARYLAND DEPARTMENT OF THE ENVIRONMENT FOR ASSISTANCE AND REPORT THE SPILL
  • For liquid mercury spills larger than the contents of a single thermometer (contents may be as small as a dime or as large as 2 tablespoons or quarters), most environmental protection and environmental health experts advise evacuating the area and calling government or private consultant professionals to perform the clean-up.  When these larger spills of liquid mercury occur, some also recommend indoor air monitoring to assure that the mercury has been cleaned up and that there are no unsafe levels of mercury vapor remaining in the room.

ADULTS ARE ENCOURAGED TO FOLLOW THESE STEPS FOR CLEANING UP BROKEN GLASS THERMOMETERS CONTAINING MERCURY, which is the most frequently encountered mercury spill or release in homes and schools:

  • Keep children and pets away from the broken glass.
  • Wear chemically resistant household cleaning gloves.  DO NOT TOUCH anything that might be released from the broken glass that appears bright or shiny silver.
  • Be especially alert to the presence of bright and shiny liquid mercury beads, droplets, or small balls that may glide along the surface of most household surfaces when released from broken glass thermometers.   DO NOT TOUCH THE SILVER LIQUID MERCURY BEADS OR DROPLETS WITH YOUR BARE HANDS.  This type of mercury can enter your body by direct contact or accidental ingestion, which is why gloves are recommended.  CHILDREN AND PETS ARE ESPECIALLY ATTRACTED TO THE SHINY LIQUID MERCURY BEADS BECAUSE OF THEIR BRIGHT GLIMMERING APPEARANCE AND THE FACT THAT THE BEADS APPEAR TO GLIDE OVER HARD, SMOOTH SURFACES, SUCH AS PAVED CONRETE, TILED, OR CERAMIC FLOORS.
  • A graphic representation of what liquid mercury beads or droplets look like and additional details on what you should do if you have a small mercury spill can be found at the EPA Office of Solid Waste and Emergency Response mercury web site,  http://www.epa.gov/mercury/spills/index.htm
  • If you see any released mercury, take steps to minimize release of the mercury into a vapor or gas by temporarily turning off any near-by fans and closing near-by heat vents or windows and doors.  After the thermometer’s clean-up is complete, open the doors and increase the ventilation in your home.
  • DO NOT USE A VACUUM SWEEPER, BROOM OR OTHER DEVICE TO ATTEMPT REMOVING THE MERCURY.  IT WILL ONLY SPREAD THE MERCURY AND MAKE REMOVAL OF THE MERCURY MORE DIFFICULT.
  • If liquid mercury from the thermometer has been released, clean it up indirectly using a small glass siphon (sucking) system.  For very small amounts that might escape a single household thermometer, a glass medicine eyedropper such as found in a drug store can be used as the siphoning system to suck up the released liquid mercury. If an eyedropper cannot readily be found or purchased, an alternative clean-up system involving transfer of the mercury to a disposable, absorbent material such as soft tissue paper supported by more rigid paper can sometimes be attempted.  (See this EPA link for additional information on materials needed and additional steps at  http://www.epa.gov/mercury/spills/index.htm).
  • Although most escaped liquid mercury forms beads and droplets that can be sucked up using a small glass eyedropper, there may be times when very rough household surfaces, such as carpets, furniture, or clothing, can trap the liquid mercury or make those items appear stained.  When this happens, it is best to remove the material that has become stained and no longer use it.   (See EPA link for additional information and steps.)
  • Until you can properly dispose of the mercury materials, you should temporarily store the broken glass thermometer and any liquid mercury you captured in your glass siphon system in an airtight plastic or glass container to prevent possible mercury gas being released over time. Common household containers with airtight lids and seals (e.g., an empty mayonnaise jar, a canning jar, or enclosed plastic milk bottle) can serve as a temporary holding container for the mercury and broken thermometer.  Choose a container large enough to contain your mercury spill materials.
  • Label the container or jar clearly as “Mercury and broken glass” or “Mercury Waste”.   As an extra security measure, after sealing the lid tightly on the container, you can apply duct tape or plastic mailing/wrapping tape around the lid.  Keep that container in a locked area and out of the reach of your children for a short period of time, until you can dispose of the container properly.  As soon as possible, take the container to a household hazardous waste disposal or reclamation center, if one is available.  DO NOT KEEP THE CONTAINER AND ITS MATERIALS IN YOUR HOME FOR VERY LONG.
  • TO PROTECT THE ENVIRONMENT, IT IS BEST NOT TO DUMP THE BROKEN THERMOMETER OR MATERIALS INTO THE TRASH.
  • DO NOT DUMP THE LIQUID MERCURY DOWN ANY HOUSEHOLD DRAINS.
  • In Maryland, you can find mercury reclamation centers in many local areas.
  • You can also contact the Household hazardous waste collection sites in your local jurisdiction in Maryland and drop off your broken glass thermometer mercury waste at these locations on certain dates of collection.

MDE has a number of additional web pages on mercury with helpful information.  For a complete listing, see the MDE mercury pages.

Additional links for mercury web page:

EPA mercury website link
www.epa.gov/mercury

ATSDR TOXFAQSTM Mercury
www.atsdr.cdc.gov/tfacts46.html​​