Maybe a much larger safe would be a better idea. I'm sure there are many cleaning products, lawn and garden products, and probably even automotive type products that need to be kept well secured too. Oh and don't overlook the laundry. The medicine cabinet is a given.
My point is, there are plenty of things around that can be harmful to unsupervised kids. None of them seem to get locked in safes.
When I raised my kids I kept many things locked up.
Prescription Drugs. Hand Guns. Legal Documents. Etc.
I didn't locking up Drain-O or Bleach but then again I did keep them low in the kitchen either. And Chemicals such as Paint Thinners or Acetone were kept high in the garage to.
My kids were good about not getting into things. But my sisters kids were terrible. They would build towers to get into things like Medicine Cabinets or the Liquor Cabinet above the frig. Had to watch them 24-7. But then again, my sister didn't believe in scolding children.
I'd never tell someone how to live their life or raise their children. If you don't have any kids in your house or if you think it is ok for things to be left out with kids around, who am I to say what's right for you.