Do CFLs contain mercury?

Compact fluorescent light bulbs (CFLs) use only one-quarter of the energy of incandescent light bulbs and last about 10 times longer. They also contain trace amounts of mercury, which can release toxins into the air if disposed of in a landfill.

The mercury in a CFL is sealed within the glass light bulb, which usually looks like a spiral tube. The average amount of mercury within that seal is 5 milligrams—about enough to cover the tip of a ballpoint pen. That’s 100 times less than the amount of mercury in an old manual thermometer.

CFLs don’t release mercury when they burn. The mercury in a CFL helps it to burn efficiently, and it stays inside the tube unless the glass breaks.
So be careful not to break a CFL. Take care when you remove a light bulb from its packaging, or install it or replace it. Screw it into the fixture securely, but don’t use force.

When your bulb burns out, bring it to a lighting, hardware or home store that accepts used CFLs for recycling. Look for promotions sponsored by APS; you could get a free replacement bulb if you turn your old one in on the right day.