If a mercury thermometer breaks (or other items containing around ¼ teaspoon or less of mercury), you may be able to clean it up yourself by following the advice on this page.
If you spill more than a quarter teaspoon, you should follow the advice on this page and seek help from professional hazardous waste disposal companies to clean up the spill. Contractors can be contacted through the Yellow Pages under ‘Waste Disposal’.
Liquid mercury is not readily absorbed through skin, but it does vaporise at room temperature and inhalation of this airborne vapour can be harmful to human health. If a thermometer breaks in the mouth, and the mercury is swallowed, there is no need to be concerned because elemental mercury is poorly absorbed in the gut and so it is virtually non-toxic by this route.
Amount of mercury in various items:
- Thermometer – 0.5–3.0 grams (less than 1 quarter teaspoon)
- Thermostat – 3–5 grams (around 1 quarter teaspoon)
- Sphygmomanometer (blood pressure measuring device) – 100–200 grams (less than 1 tablespoon)
- Typical barometer – 450 grams (2 tablespoons)
What NEVER to do when cleaning up a liquid mercury spill
- Never use a vacuum cleaner or a broom to clean up the spill.
A vacuum cleaner or broom will break the mercury into smaller drops and scatter the mercury droplets increasing the spread of mercury in the room. The droplets will evaporate faster and increase your chance of breathing in high levels of mercury vapour.
- Never use household cleaning products to clean up the spill.
Household cleaning products, especially those containing chlorine or ammonia, may react violently with the mercury and release toxic gases.
- Never pour mercury down a drain.
The mercury can become lodged in the ‘p’ traps and may continue to vaporise in the room. Mercury can also pollute septic tanks or wastewater treatment plants.
- Never allow people who are wearing mercury-contaminated shoes or clothing to walk around the house.
- Never use a washing machine to launder clothing or other items that is visibly contaminated with mercury.
Mercury can contaminate the washer and/or pollute waste water. If mercury is visible on clothing place it in a plastic bag and seal for disposal.
What you should do
- Clear and ventilate the room immediately.
Keep children and pets out of the contaminated area. Close all doors to the room to prevent mercury from escaping into other parts of your home. Open the windows for at least 24 hours. Turn off the heating or air conditioning to prevent air in the contaminated room from travelling into other parts of the house.
- Prepare yourself.
Prior to cleaning up the spill, put on an old set of clothes and shoes, and rubber gloves. Any clothing that comes into direct contact with the mercury should NOT be washed, but rather thrown away. Remove all jewellery so the mercury does not bond to the metals.
Respiratory protection is not required when dealing with small mercury spills or using powdered sulphur but some individuals may feel more reassured by wearing a mask – if this is the case, seek advice from a local protective equipment store.
- Collect Cleanup Supplies.
A mercury spill kit may be obtained from some safety equipment and products shops for around $85.00. Clean up supplies are also available from hardware stores. The following are some common household articles that could be used to construct an in-home mercury cleanup kit.
- Eye dropper – to pick up the mercury
- Wide mouth plastic container with lid – to hold the mercury
- Tape (wide, duct, or masking) – to help pick up mercury beads
- Plastic bags with zipper seal – to store mercury-contaminated debris and equipment
- Rubber gloves – to protect hands from mercury contact
- Rubbish bags – for containing mercury waste
- Stiff paper or cardboard – for collecting mercury beads
- Flashlight – to reflect mercury beads
- Powdered sulphur – optional (available from garden centres and chemists)
- Put on a pair of rubber gloves. Do not touch the liquid mercury with your hand.
- Pick up with care any broken pieces of glass or sharp objects. Place all broken objects on a paper towel. Fold the paper towel and place in a zip lock bag. Seal the bag.
- Cleanup for hard surfaces
- Use the 2 pieces of stiff paper or cardboard to slowly push the mercury beads together and then scoop them up. Place the beads in the plastic container. Tighten the lid securely so that the liquid and vapour will be contained.
- Use an eyedropper to pick up the beads you can’t get with the stiff paper or cardboard. Hold the eyedropper almost parallel with the floor, or it will not work very well. Clear the eyedropper by gently squeezing the contents into the container. If you do not have an eyedropper, press the sticky side of the tape to the remaining beads and dispose of the tape into the container. (Note: Tape only works on small beads of mercury, not large droplets.)
- When you think you’ve picked up all the mercury, shine a flashlight (at many different, low angles) on the area, to find any remaining mercury beads or glass. Light will reflect off the mercury beads and glass helping you to locate them. (Note: Mercury can move far on hard flat surfaces, so inspect the entire room.)
- A damp, disposable rag or paper towel should then be used to do a final wipe of the area.
- Optional additional step: you may use commercially available sulphur to absorb beads that are too small to see. Sprinkle powdered sulphur over the spill area and the yellow powder will turn brown on contact with any missed mercury. Collect the powder as was done with mercury beads. The sulphur will bind with the mercury, so that it can be easily removed, and it will also suppress mercury vapour, reducing the amount of vapour released to the air. (Do not apply to carpet or soft items as it may cause staining. Keep the room well ventilated and do not breathe sulphur powder).
- Cleanup for carpet, rug or upholstery.
- Clean the mercury up as above. If it is difficult to gently push mercury beads through the pile of the carpet or rug, use an eye dropper to pick up the mercury. Rugs can be discarded or hung on an outside clothesline for several days to air out.
- If the mercury cannot be retrieved from the contaminated material:
- Cut around the spill and place the contaminated item and all items used for cleanup in a plastic bag.
- Place the bag into a second plastic bag and seal the outer bag with tape.
- Remove mercury from shoes, clothing, and skin.
Remain still, if mercury has touched your skin, shoes or clothing. Have someone bring you wet paper towels and a plastic bag. Wipe off any visible beads of mercury with the wet paper towels and then place them into the plastic bag. Remove contaminated shoes and clothing and place them in a plastic bag. Seal the bag and place it in another bag.
- Properly dispose of contaminated cleanup materials.
Wrap all debris and cleaning material well (including the eye dropper, cardboard, gloves etc) and place in a sealed plastic bag. Place the zipper seal bags that contain mercury and other objects into the rubbish bag. Close and seal the rubbish bag and dispose in accordance with your council regulations.
- Continue ventilation.
Remember to keep the area well-ventilated to the outside (open windows and run any available fans) for at least 24 hours after your successful clean-up. Continue to keep pets and children out of the clean-up area.
- Wash clothing or other items exposed to mercury vapour.
Spills more than a quarter teaspoon
If spill is more than a quarter teaspoon, follow the instruction below:
- Have everyone else leave the area – don’t let anyone walk through the mercury on their way out.
- Open all the windows and doors to the outside.
- Turn off the heating or air conditioning system.
- Shut all doors to other parts of the house, and leave the area. Don’t vacuum.
- Seek help from professional hazardous waste disposal companies to clean up the spill.