The new energy efficient light bulbs contain small amounts of Mercury and precautions must be taken when disposing of them.Disposal of A Burnt Out BulbA bulb that is burnt out should be sealed in either a thick freezer bag or two regular plastic bags. Ideally, they should be taken to a place that is equipped to handle hazardous materials.What to Do When a Bulb BreaksFirst, open a window and evacuate the room for at least 15 minutes. While wearing rubber gloves use a piece of stiff paper or cardboard to gather up the residue. Never use a vacuum cleaner. Wipe down the area with a damp paper towel, and if necessary, use tape to collect any remaining powder. Seal the pieces as you would if disposing of a burnt out bulb.