Fluorescent lighting is environmentally friendly — for the same amount of illumination they use up to 75% less electricity than incandescent lighting, which was widely used earlier.  In most countries, electricity is generated by power plants burning fossil fuels and releasing greenhouse gases, so saving electricity also reduces greenhouse emissions.

However, fluorescent lighting contains a small amount of mercury, which is toxic.  Though homeowners are allowed to throw away fluorescent tubes/lights in the trash, it is better option to dispose of them at a local recycling center so that the mercury can be contained.

Additionally, old models of  the ballasts used in the fluorescent tube lights used to contain PCBs (polychlorinated biphenyls), which are carcinogens and environmental poisons so it is important to dispose of old fluorescent lighting fixtures safely .