Is there a minimum fire rating you'd suggest?
A UL level 15 is probably the minimum to go with. Apparently to get a UL rating takes a bit of money for the testing to be done and many manufacturers don't go through it. They give it a fire rating but not a UL (underwriters laboratory) rating.
Poured insulation makes a HUGE difference in ability to resist heat.
One picture is a Browning gun safe with firewall(sheetrock) insulation and the other has poured insulation.
