screw in fluorescent bulbs

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1773147549


I was wondering are thesee screw in type fluorescent lights ok to use??

and are they hazardous because i could buy 2 of them which are 1920 lumens and be at 3400 lumens of light and not have to buy a bunch of copact 15 watt fluorescent lights.

 

so is 3 good for all the growing stages