i always keep everything 1foot away from 250 to 600hps and 2 foot any bigger"1000".
anything you think might go wrong will.
fires and burned plants happen.
and who wants the fire crew round, putting out your grow?./
just be carful, hps are very hot and i once had an hps fall and burn a hole in my wood closet.
them lights get hot.
saftey 1st.