Copper II wood treatment for replacement floor

I would think so long as you don't eat the floor, you'd be fine. PT wood isn't as bad as it used to be, They removed the arsenic from the equation. Think I'd coat the underside (road side) of the plywood with preservative as well.

I find it amazing the builders use OSB for flooring. OSB, when it gets wet, turns to mush and the roadside will get wet.

Again, all about the cheapest materials.

and... OSB is loaded with formalhyde.