One of the disadvantages of not having the email address of the author is that you can't do the following without disturbing everyone...

Excellent posting. Lots of nice information. Well done.

I've had three explosions of small non-halogen incandescent lamps at home and one at the museum where I volunteer. These are 60 watt candelabra bulbs used in chandeliers of the type GE 60CAC CD4 (though I don't know if they were all GE).

My theory is that when they burn out, the break in the filament strikes an arc, vaporizing the filament, producing enough gas to cause the bulb to explode because of the small space in the miniature lamp for it to expand and cool.

One factor would be high line voltage, increasing the chance of an arc on burnout; also the short life. My home line voltage had been running about 10% above normal and sometimes high enough for me to call the power company to have it reduced. They said it was a faulty regulator. It has been replaced, and

no explosions since.

Another factor might be high inductance in the line. This would help sustain an arc. My house is fed through two transformers (overhead hi line to underground feed to line voltage). I don't know about the museum's line voltage but the power feed is similar to mine. The museum also has had several failures of electronic fluorescent lamp ballasts.

If you continue to have problems I would have an electrician or a power company representative check line voltage, line impedance, and power factor at the circuit you are using.

Or use another type of lamp.

In a message dated 2/29/2012 8:55:36 P.M. Eastern Standard Time, [log in to unmask] writes:

Thanks everyone who has weighed in so far. Our maintenance/facilities guys will be checking into things more in the morning before we open. So far their best guess is some sort of power surge.
To answer some questions:

No, we've not been in the habit of wearing gloves to change bulbs. We'll definitely start! (Am I the only one who'd never heard of this?)

The fixtures are rated up to something like 100 watts. We're significantly under.
The bulbs we've been using are GE Halogen Edison Flood, 60 watts. PAR 30. (Here's the exact bulb, if this helps: http://www.amazon.com/85116-Indoor-Floodlight-Halogen-60-Watt/dp/B00291WZTW/ref=sr_1_5?s=hi&ie=UTF8&qid=1330554039&sr=1-5)
In general, these bulbs have not been lasting the 3,000 hours promised on the packaging. Based on the number of bulbs we've purchased in the past year, I'd say they're lasting, on average, less than half that long, although whether we're replacing bulbs from 10 fixtures monthly or 100 yearly is unclear. We've recently started tracking when we replace the bulb in any given fixture so we can (hopefully!) eventually figure out whether the problem is with our hardware, or with the bulbs themselves.
We're located in northern Utah - definitely no lightning strikes we could attribute anything to recently. Today's weather is wet and windy. I don't recall the weather the day the other exploded.

Vibration is a possible concern. We share a building with the Senior Center (we're City funded), and they are upstairs. While things are generally pretty tame, they do sometimes have clogging and/or square dancing classes up there which rattle the whole building quite a bit. Bulbs exploding do not seem to correlate to building vibrations, however.
We have not switched brands recently.
There's not a dimmer on any of these.
No recent construction or additions to the building's electrical system.

Thanks again for all the helpful suggestions. Please keep them coming if you think of anything else.

Thanks,

Kaia