Some thermometers and light bulbs contain very small amounts of mercury. If you break one, it's unlikely to cause any health problems. However, you should avoid contact with the mercury and take extra care when cleaning it up.
Mercury is a metal that's liquid at room temperature. It looks like silvery-white beads or balls (globules). Liquid mercury is sometimes called metallic or elemental mercury.
Liquid mercury can turn into a vapour (gas), so clean up a spill as safely and quickly as possible using the tips below.
The amount of mercury in a thermometer is very small, usually up to 3g.
Mercury thermometers are being phased out. You can use several other types of thermometer to take someone's temperature, such as digital thermometers, thermometer strips and ear thermometers.
For more information about other types of thermometer, including how to use them, see How do I take someone's temperature?
Traditional tungsten or filament light bulbs don't contain mercury. These bulbs are being phased out and replaced with energy-saving light bulbs.
Some energy-saving light bulbs contain a tiny amount of mercury, sealed inside the bulb. In one bulb, there's usually less than 4mg (about enough to cover the tip of a ballpoint pen).
Fluorescent light strips or tubes, such as those sometimes used in kitchens and garages, also contain small amounts of mercury.
If these bulbs are unbroken, they can usually be recycled at your local recycling centre.
If you break a mercury thermometer or light bulb, a small amount of liquid mercury may spill out. Liquid mercury can separate into small beads, which can roll some distance away. The mercury may also evaporate into vapour.
However, this small amount of mercury is extremely unlikely to cause problems for your health.
It's sensible to take extra care when you clean up the mercury. Below are some tips to help you do this:
Local councils provide facilities where you can dispose of the hazardous waste, such as local tips and recycling centres.
Mercury spills on absorbent surfaces, such as carpets and upholstery, can be difficult to clean up. In these cases, it is advisable to get in contact with your local authority's environmental health department. The affected areas may need to be removed and disposed of in a particular way.
When cleaning up a mercury spill:
Although mercury is poisonous (toxic), it usually only causes problems if you inhale large amounts of it.
Very little mercury is absorbed by your body if you swallow a small amount of liquid mercury or get it on your skin for a short time. This is considered almost non-toxic and you'll probably have no symptoms.
However, if you breathe in mercury vapour or globules, it can be absorbed into the bloodstream and cause symptoms such as:
Your eyes may be sore if mercury vapour gets into them. Your eyelids may also twitch and become red and swollen.
You should contact your GP for advice if you have any of the symptoms above.
Wash your skin or eyes (removing any contact lenses first) with lukewarm water for at least 10 to 15 minutes if they come into contact with mercury.
Change your clothes and put any soiled clothes in a sealed bag.
You can also call NHS 111 for advice if you're not sure whether you need to see your GP.