Recycling

Recycling is not only a process of reducing energy usage, but also relates to human& animal safe. Some kind of light source, CFL lamps for example, contains toxic mercury, which makes recycling more difficult.
Take CFL lamps for example, they contain mercury as vapor inside the glass tubing. Most CFLs contain 3-5 mg per bulb, witch bulbs labeled" eco-friendly" containing as little as 1mg. But mercury is poisonous; even these small amounts are a concern for landfills and waste incinerators.
So when choosing your light, please consider its recycling factors after it burn out.