Compact fluorescent bulbs

Public

I couldn't help but pause the other day when I heard people on the radio talking about compact fluorescent bulbs containing mercury and the need to take care if they break.

It reminded me of the dialogue that occurred on the doclounge list serv a few months ago about the clean up after a broken mercury sphygmomanometer. As I recall, that clean up was a LOT more than just picking up the pieces with a paper towel and throwing that away with the debris.

Anyway, I am really confused, especially now that the old incandescent ones are being phased out.

I found this article from the Vancouver Sun, "Fluorescent bulbs cast 'bluer' light -- get used to it" and discovered even more.

" ... Though the light emitted from both types of bulbs is white light, the light from fluorescent bulbs is slightly bluer, says Gary Hamer, BC Hydro's technology innovation expert, and therefore closer to daylight.

By contrast, the light from incandescent bulbs is more reddish – more evocative of the light a fire casts -- and therefore "cosier" to us, he says. Which is why many of us might prefer the light from an incandescent bulb.

" ... By comparison, the fluorescent bulb is much more technologically advanced, which is why when it malfunctions it may smoke or smoulder.

Instead of simply firing up a piece of metal the way the standard incandescent bulb does, fluorescent bulbs work by heating individual atoms of mercury inside a curving glass tube. When these atoms get excited, they emit photons of light, which then react with phosphors placed all over the glass surface.

"... the fact that mercury is involved means that, like paint, when it's time to dispose of a fluorescent light, it has to be done in an environmentally responsible way, says Hamer.

Now, about that smouldering. At the base of fluorescent bulbs is a small circuit board that regulates the voltage and current inside them. Occasionally, explains Hamer, these circuit boards will malfunction, and when they do, they will smoke or smoulder. That's why, he adds, we sometimes hear of people complaining about fluorescent bulbs catching fire.

In fact, Hamer says, they're specifically designed not to catch fire, thanks to a plastic coating that is "self-extinguishing."

But again, because mercury is present, they need to be handled carefully.

And halogen bulbs? They work much the way a standard incandescent bulb does, except instead of argon, they have halogen gas inside them. The advantage this confers is that as the tungsten burns away, the halogen combines with the tungsten vapour in such a way that some of the tungsten is returned to the filament."

So, what's the deal, should we be quick to replace our bulbs or hang on to those incandescent bulbs and find other ways to reduce our carbon foot print?