[Mercury is the most poisonous element on earth, so we are surprised to find it in compact fluorescent lamps, CFL’s. Here is what DEFRA has to say:-]
Do CFLs contain mercury?
Yes, they need mercury to generate light efficiently. The mercury is used to produce ultraviolet light, which is then changed into light we can see by a special coating in the lamp. The coating is inert and poses no health risk. Nowadays, the typical amount is under 4 milligrams per lamp: just enough to cover the tip of a ball point pen and just enough to last as long as the lamp.
Does the mercury in a CFL pose a risk?
The mercury cannot escape from an intact lamp; and even if the lamp breaks, the very small amount of mercury contained in a single modern lamp is most unlikely to cause any harm. But it makes sense to avoid unnecessary contact with mercury; and any light bulb should be dealt with sensibly.
How should I deal with a broken CFL?
Although the accidental breakage of a lamp is most unlikely to cause any health problems, it’s good practice to minimise any unnecessary exposure to mercury, as well as risk of cuts from glass fragments. Empty the room and air it for at least 15 minutes. Don’t use a vacuum cleaner; clean up using rubber gloves and aim to avoid creating and inhaling airborne dust. Sweep up all the particles and put them in a plastic bag. Wipe the area with a damp cloth, then add that to the bag and seal it. Mercury is hazardous and the bag should not be disposed of in the bin. All local councils have an obligation to make arrangements for the disposal of household hazardous waste at a civic amenity site or household waste recycling centre.
The National Household Hazardous Waste Forum runs a website with details of these centres for chemicals, but which also applies to other hazardous wastes (www.chem-away.org.uk/). Alternatively contact your local council direct.