CFLs contain small amounts of mercury, lead, and polychlorinated biphenyl (PCBs), which, if improperly disposed of, have the potential to create huge health risks and environmental contamination problems. Each of these toxins lingers in the environment, concentrates in the food chain, and has been linked to brain damage, heart disease, and cancers.

These toxins present a risk to the consumers who may face exposure when a bulb breaks in their homes, to sanitation workers when the bulbs break during disposal (although they contain hazardous chemicals, they are not required to be disposed of as hazardous waste), to the environment through broken bulbs in landfills, and to factory workers who do not receive adequate training or working environments to protect them from the dangers of mercury, lead, and PCBs.