Mercury Thermometers
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On this page:
- Household uses
- Educational and medical uses
- Industrial uses
- Restrictions on sales
- Alternatives to mercury fever thermometers
- Cleanup and disposal after breaking a thermometer
In a mercury thermometer, a glass tube is filled with mercury and a standard temperature scale is marked on the tube. With changes in temperature, the mercury expands and contracts, and the temperature can be read from the scale. A mercury thermometer can be easily identified by the presence of a silver bulb. If the bulb is red, blue, purple, green or any other color, it is not a mercury thermometer.
Mercury thermometers can be used to determine body, liquid, and vapor temperature. Mercury thermometers are used in households, laboratory experiments, and industrial applications. The Northeast Waste Management Officials' Association (NEWMOA) provides a web site with basic information on mercury and non-mercury alternatives.Exit Also provided are links to additional on-line resources.
Household Uses of Mercury Thermometers
Common household uses of mercury thermometers include fever thermometers and oven, candy and meat thermometers.
Fever Thermometers
Mercury fever thermometers are made of glass the size of a straw, with a silvery-white liquid inside. They are common in many households, schools and medical facilities. There are two general types of mercury thermometers that measure body temperature:
- oral/rectal/baby thermometers, containing about 0.61 grams of mercury
- basal temperature thermometers (used to track slight changes in body temperature), containing about 2.25 grams of mercury
Educational and Medical Uses of Mercury Thermometers
Mercury thermometers may be used in many applications, including chemical experiments, water and acid baths, blood banks, ovens and incubators
Industrial Uses of Mercury Thermometers
Mercury thermometers are used in:
- power plants and piping
- chemical tanks and vats
- heating and cooling equipment
- breweries, canneries
- bakeries, candy making
- dairies, ships
- wineries and distilleries
- paint kettles
Phasing out Mercury Thermometers in Industrial and Laboratory Settings
EPA has launched an effort to reduce the use of mercury-filled non-fever thermometers used in industrial settings where suitable alternatives exist. As part of a partnership EPA developed with the National Institute of Standards and Technology (NIST), NIST no longer provides calibration services for mercury thermometers. You can read more about the impact the decision will have in NIST’s February 2011 press release announcing the change.
In January 2012, EPA issued a final rule incorporating updated ASTM International (ASTM) standards into EPA regulations (PDF)(11 pp, 204 K, About PDF).Exit These changes provide flexibility to use alternatives to mercury-containing thermometers. The rule applies to certain regulations pertaining to:
- petroleum refining,
- power generation, and
- polychlorinated biphenyl (PCB) waste disposal.
To date, multiple ASTM standards have been updated to approve the use of mercury-free alternatives for temperature measurement. View a list of the updated ASTM standards.
For more information about phasing out industrial mercury thermometers, visit EPA's Phasing Out of Mercury Thermometers Used in Industrial and Laboratory Settings page.
Restrictions on Sales of Mercury Fever Thermometers
Some states and municipalities have passed laws or ordinances barring the manufacture, sale and/or distribution of mercury fever thermometers. This is to help remove the threat of thermometer breakage and the subsequent release of mercury vapor indoors. Thirteen states have passed such laws. They are: California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon, and Washington. The Health Care Without Harm Web site presents information on specific state laws, resolutions and declarations.Exit
Alternatives to Mercury Fever Thermometers
A variety of accurate and reliable mercury-free fever thermometers are available at your local pharmacy. The most similar alternatives to mercury fever thermometers are battery and solar powered digital thermometers. These are alike in both price and use. These can all be used orally, rectally, or in the armpit. You should choose a thermometer that is easy to use and read.
If you are choosing a battery powered digital thermometer, choose one that contains a replaceable battery. Some of these thermometers do not have replaceable batteries. The battery is a button cell battery and may contain a small amount of mercury, so it should be recycled with a hazardous waste collection program. You can use Earth911's Recycling Locator Exit to find a mercury recycling center near you.
Mercury Thermometer Cleanup and Disposal
If you break a thermometer while using it or if you improperly dispose of it, the thermometer will release mercury vapors that are harmful to human and ecological health.