Written and maintained by CASRAI Editorial Board
Last updated
This page describes products and general use; it is not medical advice.
Short answer: mercury from a thermometer is never poured down a drain, and the route for disposing of an unwanted or broken thermometer is set locally. The U.S. Environmental Protection Agency (EPA) tells people to contact their local health department, municipal waste authority or local fire department to learn how to dispose of mercury waste in line with local, state and federal rules, and points to a recycling locator for mercury products. Who uses this page: clinic staff, lab staff, students and households deciding what to do with a glass fever or lab thermometer. After reading it you should know what counts as mercury waste, who to call, and what to avoid.
What counts as a mercury thermometer
A mercury thermometer is a glass tube filled with mercury and marked with a temperature scale; the mercury expands and contracts with temperature. EPA lists two common fever types: oral, rectal and baby thermometers contain about 0.61 grams of mercury, and basal thermometers about 2.25 grams. Mercury thermometers are also used in laboratories (for example in water baths, incubators and ovens) and in industry.
Not every glass thermometer holds mercury. EPA says that if the liquid is any color other than silver it is not mercury, and that a paper calibration strip reading “mercury free” means the liquid is not mercury. If you do not see those words and the liquid is silver, EPA says to assume it is mercury. For how mercury sits in the instrument, see mercury in a thermometer; for the health background, see why mercury is dangerous.
Where each item goes: a disposal route chart
| Item | What EPA says | Source |
|---|---|---|
| Intact mercury thermometer you no longer want | Improper disposal lets the thermometer release mercury vapors that are harmful to human and ecological health. EPA links to guidance on recycling and disposing of mercury products and suggests the Earth911 Recycling Locator to find a mercury recycling center. | EPA, Mercury Thermometers |
| Broken glass from a broken thermometer | Place on a paper towel, fold it into a zip-locking bag, seal it and label it as directed by your local health or fire department. | EPA, What to Do if a Mercury Thermometer Breaks |
| Cleanup materials, including gloves | Put everything, including the mercury beads and objects, in a trash bag, place the bag outside in a secured area and label it as directed by your local health or fire department. Then contact your local health department, municipal waste authority or fire department to find out how to dispose of it under local, state and federal law. | EPA, What to Do if a Mercury Thermometer Breaks |
| Button-cell battery from a digital thermometer | May contain a small amount of mercury, so EPA says it should be recycled through a hazardous waste collection program. | EPA, Mercury Thermometers |
If a thermometer breaks
EPA publishes a full small-spill cleanup procedure, and this page does not replace it. The disposal point to keep from it: sealed bags are labeled as your local health or fire department directs, and the final disposal route comes from a local authority, not from the household bin. For a broader spill, see EPA’s page for spills larger than a thermometer.
What never to do
- Never pour mercury down a drain. EPA says it may lodge in the plumbing and cause problems during later plumbing repairs, and can pollute a septic tank or sewage treatment plant.
- Never use a vacuum cleaner. EPA says it puts mercury into the air and increases exposure.
- Never use a broom. EPA says it breaks the mercury into smaller droplets and spreads them.
Laboratories and clinics
EPA notes that mercury thermometers have been used in chemical experiments, water and acid baths, blood banks, ovens and incubators, and that it has run an effort to reduce mercury-filled non-fever thermometers in industrial and laboratory settings where suitable alternatives exist. The EPA page also states that NIST no longer provides calibration services for mercury thermometers. Facility rules on mercury-containing waste come from your institution and your state, so confirm the route with your environmental health and safety office. See laboratory waste disposal and the universal waste disposal requirements entry for the general framework.
Mercury-free replacements, accuracy and safety
Are mercury thermometers still sold?
Some states and municipalities bar the manufacture, sale or distribution of mercury fever thermometers. EPA’s page says at least 13 states have passed such laws: California, Connecticut, Illinois, Indiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, New Hampshire, Rhode Island, Oregon and Washington.
What does EPA recommend instead?
EPA recommends mercury-free thermometers without endorsing any brand. It says mercury-free fever thermometers are available at local pharmacies and that battery- and solar-powered digital thermometers are the most similar alternatives. If you choose a battery-powered digital model, EPA suggests one with a replaceable battery. Product basics are in what a medical thermometer is, and accuracy is discussed in thermometer accuracy.
For diagnostic and monitoring equipment generally, see diagnostic, monitoring and imaging equipment.
FAQ
Can I throw a mercury thermometer in the trash?
EPA’s guidance sends you to local authorities for the disposal route: your local health department, municipal waste authority or fire department. Contact one of them before putting any mercury waste out.
Where can I recycle a mercury thermometer?
EPA suggests the Earth911 Recycling Locator to find a mercury recycling center near you.
How do I dispose of a broken mercury thermometer?
Seal broken glass and cleanup materials in labeled bags as your local health or fire department directs, keep the sealed bag outside in a secured area, and ask that department how to dispose of it.
How do I dispose of a digital thermometer battery?
EPA says button-cell batteries may contain a small amount of mercury and should be recycled through a hazardous waste collection program.
Sources
- U.S. EPA, What to Do if a Mercury Thermometer Breaks, checked 2026-10-30.
- U.S. EPA, Mercury Thermometers, checked 2026-10-30.
