Propane tanks need to be outside, and if inside a confined space like a cabinet or box, it must have ventilation in the floor. Propane is more heavy than air, so it will vent out the bottom VS going BOOOOOOM if it stays confined.
Best is a sheet steel box, with expanded metal bottom.
Every tank also needs to be secured. Rubber tarp straps don't count.
"Don't argue with stupid people. They will just drag you down to their level, and beat you up with experience."
Patently waiting for the apocalypses to level the playing field in this physiological game of life commonly known as Civilization