The short answer is YES. CFLs contain mercury, a potentially dangerous substance. The mercury in CFL bulbs does not pose a risk if contained safely contained inside an intact bulb, but if the bulb is broken you do need to handle it with care and follow certain procedures to remove it and its contents safely.
While one broken CFL bulb does not put your family or business’s inhabitants in immediate grave danger, consider hundreds, thousands, millions of broken CFLs in our landfills, leaching into the ground. But don’t worry, there’s no need for an enviromental HAZMAT crew to be dispersed if you break a bulb.
Similar to batteries, used CFLs really need to be disposed of at a toxic waste depot in your local community, rather than thrown out with the ordinary household trash. Because mercury by its nature is cumulative, this poisonous substance would add up if all the broken and used bulbs went into a our community’s landfills.
We strongly recommend phasing out CFLs from your home altogether in favor of safer LED bulbs. But if you do happen to break a CFL bulb while you are switching it with an LED, see our earlier blog with recommendations for safe removal and clean up.
We find this information to be useful, at http://www.snopes.com/medical/toxins/cfl.asp.