Hello ZVTK, i want to report in and say that my personal testing of the Zevotek bulbs is still on going. I purchased a four pack last year 2009 before Christmas and recieved them also before. One bulb is in my kitchen, it was turned on and we never have shut it down once since, still shining britely and still moves the kitchen smoke and kills all odors quickly. The other three we also have in use but not continious use.