What to Do If a Mercury Thermometer Breaks at Home

Get everyone, including pets, out of the room, open windows to the outside, and never use a vacuum or broom on the spill. That is the core of the U.S. Environmental Protection Agency (EPA) guidance for a broken mercury fever thermometer. Questions about health effects go to a physician or poison control at 1-800-222-1222 (the number EPA lists, on a page last updated November 14, 2025; read in October 2026).

1. First, is it actually mercury?

Many newer non-digital thermometers use alcohol or a non-toxic liquid that looks similar. EPA gives two checks:

• Liquid that is any color other than silver is most likely alcohol. Silver liquid may be mercury or possibly a non-mercury substance.
• If a paper calibration strip says "mercury free," the liquid is not mercury. If you do not see those words, assume it is mercury.

Mercury is a liquid metal. Small droplets merge into a sphere that rolls on flat surfaces and breaks back into smaller droplets if dropped or pressed. That is why it can travel surprisingly far on hard floors.

2. What never to do

EPA's list is short and specific:

• Never vacuum. The vacuum puts mercury into the air and raises exposure.
• Never use a broom. It breaks the mercury into smaller droplets and spreads them.
• Never pour mercury down a drain. It can lodge in plumbing and pollute a septic tank or sewage plant.
• Never walk around in shoes that might be contaminated, and remember that contaminated clothing can spread mercury too.

3. Set up before you touch anything

• Everyone else leaves, without walking through the spill. Remove pets.
• Open all windows and doors to the outside; shut doors to other parts of the house.
• Do not let children help.
• Hard smooth surfaces (wood, linoleum, tile) are the easy case. If the spill is on carpet, curtains, upholstery or other absorbent items, EPA says those items should be thrown away under the disposal rules below, and only the affected piece of carpet should be cut out.

EPA says these steps also fit other small spills that are about the amount in a thermometer or less. Larger spills have a separate EPA page.

Supplies: 4 to 5 zip-locking plastic bags, trash bags (2 to 6 mils thick), rubber, nitrile or latex gloves, paper towels, cardboard or a squeegee, an eyedropper, duct tape or shaving cream with a small paint brush, and a flashlight. Powdered sulfur is optional.

4. The cleanup, in order

1. Put on gloves.
2. Pick up broken glass carefully, place it on a paper towel, fold it, and seal it in a zip bag. Label the bag as your local health or fire department directs.
3. Use the squeegee or cardboard to slowly gather beads into larger balls. Fast sweeping makes it harder to control.
4. Darken the room and hold a flashlight at a low angle near the floor to spot glistening beads in cracks and corners. Check the whole room.
5. Draw up beads with the eyedropper and squeeze them onto a damp paper towel, or roll them onto the towel with two pieces of cardboard. Seal the towel in a bag.
6. For tiny beads, dab the area with shaving cream on the paint brush, or lift them with duct tape, peeling slowly. Bag the brush or tape.
7. Optional: powdered sulfur. EPA says it binds mercury, suppresses vapor, and may change color from yellow to brown so you can see it. It can stain fabric and should not be breathed in, so read the product label first.
8. Put everything, including gloves, into a trash bag, and place the bag outside in a secured area, labeled as your local authority directs.

5. Disposal and aftercare

EPA says to contact your local health department, municipal waste authority or fire department about proper disposal under local, state and federal rules. It does not say to put the bags in regular trash.

For at least 24 hours after cleanup, keep the area ventilated to the outside, with windows open and fans in exterior windows running. EPA notes you may request a contractor with monitoring equipment to screen for mercury vapor, and suggests asking your local environmental or health agency about contractors. Keep children and pets out of the area. If anyone becomes sick, seek medical attention immediately.

6. Why vapor is the concern

According to EPA, metallic mercury mainly causes health effects when inhaled as a vapor absorbed through the lungs. Symptoms of prolonged or acute exposure can include tremors, mood changes, insomnia, headaches and poor performance on mental function tests; higher exposures may affect the kidneys and breathing. EPA also notes that effects depend on the amount, the length of exposure, the person's age and health, with unborn infants the most vulnerable, and that effects can be severe, subtle, or absent. Metallic mercury vapor is a different thing from the methylmercury found in fish.

7. Replacing the thermometer

EPA recommends mercury-free thermometers but does not endorse any brand.

8. Key takeaways

• Check the liquid color and look for "mercury free" before panicking; if unsure, treat it as mercury.
• No vacuum, no broom, no drain.
• Everyone out, windows open, doors to the rest of the house shut.
• Gather beads with cardboard, eyedropper, shaving cream or tape; bag and label everything.
• Ventilate at least 24 hours and call local authorities about disposal.
• Poison control: 1-800-222-1222.