CFL's you will not really have to worrie about the burn, The HPS you do since they are clear. the CFL has a white coating over them so it is not direct light. How many plants do you have?
This isn't all that relevant, but the white coating on cfls is actually what lights up. Fluorescent lights work by creating an arc through mercury vapor, this arc gives off ultraviolet radiation. The lights are coated with phosphorous on the inside, which fluoresces under the uv, giving you the light you have.
Gentlemen: I'm sold on CFL's. They're cheap to run and I don't like to support the Edison company. The only complaint that I have is the replacement cost through Aerogarden but they have a big sale going on so I'm going to stock up on supplies. I like burning 60 watts of energy as opposed to 600.