CFLs giving off sparks and smoke?

December 8, 2008 4:16 AM

CFL bulbs -- cracking, smoking, sparking?

This morning when I went to start a load of laundry, the CFL bulb in the overhead fixture wouldn't light. Then I heard cracking as if glass were breaking, and a little spray of fragments shot out and a stream of thick white smoke came pouring out as the bulb began to flicker to life. Quickly I turned it off and I'll remove it with a towel later.

Has anyone else had this happen or know anything about it? I have found the below references, which seem to indicate it is not uncommon, but not one indicates what the white smoke IS, or why glass was sprayed. Is this toxic mercury smoke? What the hell is it?

Also, did you know you aren't supposed to use CFLs anywhere you turn lights on & off frequently? Or that you are not supposed to put them in overhead recessed fixtures? That would have been nice to know SOME TIME AGO when I first started replacing bulbs around the house.

I've never had anything happen with this light socket before, BTW.

Any insight appreciated.


CFL discussion forum

Star Tribune fix-it column

The Green Guide

CFL mfg FAQ

posted by jfwlucy to Home & Garden (4 answers total)

Yes, I knew about not turning them on and off frequently. Yes, I also knew about not recessing them or enclosing them. I've told people often and people like to argue...all the packages I've seen recently say it on the package. You're also not supposed to use them in cold places and they aren't intended to be dimmed unless they say so on the package.

The bulbs are vacuumed, and when you get a crack and turn it on, there's an unpleasant surprize. I wouldn't worry about it much, I'm sure you'll be ok. We used them exclusively at my last store, and we got a bad batch of GE Bulbs from Sam's where none of them lasted more than a week.

But really, if you didn't have the bulb in your mouth when it went nutty, I would think you should be fine. Just make sure the switch is off when you remove the bulb, and try to remove it by the base rather than by the glass.
posted by TomMelee at 5:19 AM on December 8, 2008

I gather from your question that you ARE aware these bulbs contain mercury and you should handle with care. You're probably fine with the cracking/smoking bulb at this point...in the future it would be good to ventilate any area that a CFL breaks in for several hours (you might be able to look up some figures on how long mercury vapor hangs around, I think its fairly substantial). When you remove it/clean up broken bulbs, make sure you wear some gloves/protect your skin.

Also, another thing people often don't know about CFL bulbs, you should not be disposing of them in your regular garbage. They need to be taken to a Hazardous Wastes Disposal center, check you city or county websites for locations.

While its not going to kill you to get a little exposure to hazardous materials like mercury once or twice...its the build-up of these substances in your body than can cause disease down the line, so its good to take precautions even if you feel silly busting out the gloves and the face mask for a simple light bulb. Same goes for disposal...it may seem silly to go to the Haz. Waste place just for some lightbulbs but every little bit of mercury in the landfill will eventually end up in the soil, in the groundwater and run-off/surface water, and eventually the oceans.

(Like the above poster said, the inside of the tube is a vacuum. There was probably a hairline crack in the bulb and the difference in air pressure inside and outside the tube caused the contents to expand/shoot out as smoke and take some glass with it as the crack burst. Something like that, my physics is a little rusty.)
posted by dahliachewswell at 10:05 AM on December 8, 2008

All of these problems will go away with the next thing, which is LED bulbs. They have no mercury, are not sensitive to shock, temp change, etc., cooler, and are easier to spell than either incandescent or fluorescent. And they last way longer: With a rated life of 30,000 to 50,000 hours, they will probably outlive you. As prices come down, they'll become a better buy than CFLs. I plan to start trying a few out, but I'm waiting for the CFLs I installed throughout a newly purchased house 2.5 years ago to start failing.
posted by beagle at 10:23 AM on December 8, 2008

Explosive CFL Failures:

Once an arc is started, it will continue until enough material has been burnt away that there is no longer a conductive path - this means that PCB tracks, components, or anything else in the circuit can be blown apart - often quite violently and usually with lots of black soot and at least some smoke.
posted by sfenders at 9:03 PM on December 8, 2008