well do you want my answer or an answer exo terra would give you?
One similar to that you would most likely get from an Exo-Terra rep:
Our light bulbs are specially designed to emit a full spectrum of lighting, yet not ranging into the potentially dangerous high uv spectrum and offering more of the low power infrared spectrum for heat.
my answer:
go to walmart get yourself a 4 pack of bulbs for 88 cents. work just as well and the dangers that they mention are so extremly minute it's absurd they even mention it. Also, walmart sells thousands of bulbs a day, where exo terra may only sell 50/day (on a good day). So production cost is a lot cheaper for the walmart bulb.
The only reason it says that they are good for reptiles is because they just went out and lobbied various corporations (probably something like the UL, FDA, or maybe even the HSUS as cruel as they are...) to get a stamp of approval. thereofre you are paying plenty for just a bunch of bull[bleep] written on the package.
But do what you want. 
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-Chris
The reason mainstream thought is thought of as a stream is because it's so shallow. -George Carlin
A fool doesn't learn. A smart man learns from his mistakes. A wise man learns from the mistakes of others. Which one are you?
My Website
N. American Rat/Corn snake care sheet I wrote
Information on substrates
Current snakes:
0.1 Licorice Stick Black Rat (Lola)
1.0 Black Rat (Frankie)
0.1 Texas Bairdi (Rosa)
0.1 Blue Beauty (Brunhilde)
1.0 Green Tree Python (Monty)