HN Explorer

Why I may be going back to incandescent light bulbs

2 points by natch ↗ HN
I'm considering going back to incandescent light bulbs, even though this will mean my energy bills will go up, and I'm wondering if anyone else is seeing the same thing as I am:

At our house we have had CF bulbs for something over five years. We have now had three incidents of bulbs spontaneously cracking open at the end of their life. Why is this a problem? Mercury exposure. I have no idea how much mercury we have inhaled since this began. We have also had some bulbs die without obvious cracking [edit: and I wonder if maybe they have leaked too, since I wasn't looking for the problem until now], but the most recent bulb to die did so while I was in the room, and I noticed it happening, so I got to see what was going on.

The bulb was flickering and the gas at the base of the tubes (where they enter the body of the screw-on portion) was turning orange. I decided to remove the bulb before it had a chance to break. Very shortly, in the few seconds it took me to remove the bulb, the bulb started heating up. At first it wasn't even warm to the touch, and ten seconds later it was so hot I was starting to wonder if I would get it out in time to not need a glove or cloth. At that point I turned off the power (should have done that to start with) and noticed acrid plastic-smelling smoke coming out near the base of the tubes.

I'm guessing some sort of plastic or epoxy/resin material is used to seal the tubes at the base, and this was melting. And the next step, had I not been there to catch and prevent it, would have been the heating of the glass to the point where it broke.

I'm not really super thrilled about myself or my children breathing mercury vapors repeatedly as the light bulbs in my house expire one after the other over the years.

Question for HN: Has anyone else seen this? Since these bulbs are supposed to last for seven years, maybe it's a hidden problem until now? I was hoping LED lights would be the solution, but they are so dim they don't really act as an adequate substitute.

tl;dr: Upon aging, my CF bulbs have been cracking open, presumably releasing mercury vapors into my house. With 50+ light bulbs in the house, I'm concerned about this and wonder if others see it too.

4 comments

[ 3.2 ms ] story [ 18.4 ms ] thread
squidbot
I've had three cf bulbs crack at the bottom and had the same concern about mercury vapors. One thing I've noticed is that the bulbs that failed were all very inexpensive bulbs from the multipacks I picked up in discount stores. I have never had one of my more expensive bulbs break (name brand sold in a single package usually, I get these for dimmers and for spotlights.)

GE has this to say about the mercury and safe handling of broken bulbs: http://www.gelighting.com/na/home_lighting/ask_us/faq_compac...

mechanical_fish
The GE Lighting FAQ (thanks, squidbot):

http://www.gelighting.com/na/home_lighting/ask_us/faq_compac...

says that GE's bulbs contain about 5mg of mercury apiece.

The OSHA guidelines on mercury vapor:

http://www.osha.gov/SLTC/healthguidelines/mercuryvapor/recog...

... states the following:

The current Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for mercury vapor is 0.1 milligram per cubic meter (mg/m(3)) of air as a ceiling limit. A worker's exposure to mercury vapor shall at no time exceed this ceiling level.

The National Institute for Occupational Safety and Health (NIOSH) has established a recommended exposure limit (REL) for mercury vapor of 0.05 mg/m(3) as a TWA for up to a 10-hour workday and a 40-hour workweek.

Now all we need to know is that a 12 foot by 12 foot by 8 foot bedroom is about 4 by 4 by 2.5 meters, which adds up to about 40 cubic meters. Break a mercury bulb in that room, disperse 100% of the mercury in the bulb throughout the room, assume the room is leakproof, and stay in the room breathing deeply for several minutes after the bulb breaks and you'll get exposed to 0.125 mg/m(3). This is about twice as high as the maximum amount that you should be breathing for 10 hours per day, 40 hours per week. But it is barely above the maximum legal exposure limit for workers.

Now consider that your bedroom isn't airtight -- assuming your house is either properly ventilated or improperly insulated. ;) Not only will the mercury distribute itself through the house, but it will then leave the house, within a matter of an hour. Also, not all of the mercury is likely to leak; some of it will condense in the bulb. And all of this will only happen once per bulb failure.

Conclusion: I'd find something more important to worry about. You probably don't have to look very far, because this risk is pretty low. If you just can't stop worrying without taking action, turn on a fan and open the windows for five minutes every time a bulb burns out. You'll still save plenty of energy.

Second-order conclusion: Take a class on solving Fermi problems. ;)

mickrussom
Murdercury. The sale of things that contain mercury should result in companies being charged with attempted murder.
mickrussom
Of course, murdercury containing lightbulbs are obsolete:

http://www.envirowarrior.com/pharox-light-bulb/

But the GE and the military industrial complex wants us to buy 50 years obsolete poisonous garbage bulbs instead of using things like Pharox bulbs.

GE lightbulbs with Hg = murder.