According to
a study done by UC Irvine, they found that
Lim et al wrote:The CFLs and LEDs have higher resource depletion and toxicity potentials than the incandescent bulb due primarily to their high aluminum, copper, gold, lead, silver, and zinc. Comparing the bulbs on an equivalent quantity basis with respect to the expected lifetimes of the bulbs, the CFLs and LEDs have 3–26 and 2–3 times higher potential impacts than the incandescent bulb, respectively. We conclude that in addition to enhancing energy efficiency, conservation and sustainability policies should focus on the development of technologies that reduce the content of hazardous and rare metals in lighting products without compromising their performance and useful lifespan.
Considering what UC Irvine has found out about
CFL's, it is already apparent that CFL's are toxic, because of the
protocols that the EPA suggests for cleaning up a broken CFL:
EPA wrote: Before Cleanup
Have people and pets leave the room.
Air out the room for 5-10 minutes by opening a window or door to the outdoor environment.
Shut off the central forced air heating/air-conditioning system, if you have one.
...
During Cleanup
DO NOT VACUUM.... could spread mercury-containing powder or mercury vapor.
Be thorough in collecting broken glass and visible powder. Scoop up glass fragments and powder using stiff paper or cardboard. Use sticky tape, such as duct tape, to pick up any remaining small glass fragments and powder...
Place cleanup materials in a sealable container.
After Cleanup
...
check with your local government about disposal requirements in your area, because some localities require fluorescent bulbs (broken or unbroken) be taken to a local recycling center. If there is no such requirement in your area, you can dispose of the materials with your household trash.