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Bullhorn Animated

Are you using mercury thermometers in incubators, water baths or other applications where a non-mercury thermometer would work just as well? Although mercury thermometers are not harmful when used properly, they pose a threat to human health and the environment when broken or disposed of as trash. The breakage of mercury thermometers is one of the most common accidents in research labs. When mercury thermometers break, drops of the liquid metal become lodged in floor cracks and behind equipment. Depending on the amount spilled and air movement within the lab, the mercury vapor concentration in a lab with "hidden" mercury spills may exceed safe limits. A spill is more dangerous when mercury thermometers break in ovens or in incubators because mercury evaporates readily at high temperatures, creating high mercury concentrations.


There are alternatives to the use of the mercury thermometers that are just as effective and affordable. The University chemistry stockroom, along with Fisher-Scientific supply "safety" thermometers that are usually filled with red mineral spirits or alcohol. The cleanup of a broken thermometer containing this material is decidedly easier and safer. Microprocessor-digital readout thermometers are also available.

Comparison of Alternatives to Traditional Mercury Thermometers
TypeHazardCostNIST Certified for Accuracy/Precision
Spirit filled Less Same Yes
Alcohol filled Less Same Yes
Microprocessor None Higher Yes1
Teflon coated mercury Less2 Slightly higher Yes

1 May be read to more significant digits and is easier to read
2 Teflon will usually contain mercury if thermometer is broken

Free Exchange

While supplies last, EHRS is sponsoring a mercury thermometer exchange program. The program is designed to collect and replace -- for free -- potentially hazardous mercury thermometers with environmentally friendly ones. EHRS can exchange Total Immersion thermometers (-20° to 110° C and 20 to 150° C). To request these thermometers, please fill out this request form or contact Jim Crumley (email) or by calling 215-746-5036.

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What to do if You Break a Thermometer

Isolate the immediate area. Mercury can be easily tracked throughout a lab by people walking on the spill. Laboratory staff can safely clean up small spills such as those from a thermometer. Avoid exposure and injury by wearing nitrile gloves (mercury is absorbed through the skin), a lab coat, and safety glasses. Use tongs or other tools to pick up glass from the broken thermometer.Mercury droplets can be swept into a container with an index card. Carefully inspect the bench top and floors where the thermometer was broken to ensure that all the mercury is cleaned up. Mercury breaks into very small droplets that are difficult to see when spilled and can spread over a large area.

Package the spilled mercury and broken thermometer and contaminated objects in a sealable plastic container. Label the container with a Hazardous Waste Label. Call EHRS at 215-898-4453 for disposal.

Contact EHRS for cleanup assistance for large spills such as those from a manometer or if a spill has contaminated surrounding equipment.

Cost of Mercury Spills and Disposal

Mercury waste is very expensive for disposal. Spill debris uses much more space than an intact thermometer. Currently, one 55 gallon drum of mercury waste shipped for disposal costs the University $1,500! Save the University's money by utilizing non-mercury thermometers.

Effects of Mercury

Mercury accumulates in the environment and pollutes air and water, causing a myriad of problems in humans ranging from paralysis and insomnia to developmental delays in early childhood. The average household mercury fever thermometer holds 0.5 grams of the heavy metal, an amount sufficient to contaminate 5,000,000 gallons of otherwise pristine waters above government-established limits.

Other Links

Health Risks from Mercury


Environmental Concerns

EHRS Chemical Disposal Guidelines