how safe are HPS/MH blubs?

4x6 closet lined with 1/2 inch foam insulation and mylar on top.

i have 270watt HPS, 250w MH and about 12 23w CFLs. im using a 250w sunleaves pulsar switchable fixture. plan to grow about 4 plants

i will use the CFLs for side growth.

the closet will be vented/etc, but i am worried about a fire for some reason. these bulbs cant just blow up and cause a fire can they?

is a fan blowing on the light hood ok?

Welcome to RIU

As long as you have a good connection and everything wired correctly, you should be fine. I know the feeling though.