One of my lightbulbs went out a few days ago and I was replacing it today. I found to my surprise that the base was yellowing for no apparent reason.
I found this article online: http://www.montgomerynews.com/articles/2012/10/13/springford_reporter_valley_item/news/doc5075ce95acf4f692783257.txt
It mentions that CFL lightbulbs shouldn't be used in enclosed/contained fixture, or risk the hazard of fire:
CFLS cannot be used in lighting units where the base of the CFL is encased or enclosed. “The key is letting air around” the base of the CFL bulbs, Lengel said. That means track lighting, recessed lighting and any fixture that encloses the CFL bulb is not safe to have a CFL bulb in.
One sign of a near fire as a result of improper CFL use is when the base of the CFL bulb is turning brown.
Here are some images:
In the picture above, you can see the browning.
In the picture above, you can see the lightbulb information.
Finally, here is a shot (with the light turned out for contrast) of the fixture (there are two bulbs inside):
I would like to know if the lightbulb really is a fire hazard. If I was wrong in assuming that the bulb is not CFL, would it be a fire hazard if I did place a CFL (or two) in there?