Many states have OK'ed externally applied oxygen-ozone gas mixtures for more rapid wound healing, and the number is growing. You figure that this mixture inactivates all manner of bacteria, fungi and protozoans growing on wounds, And, their toxins, which inhibit wound closures.
The study in question was definitive: The addition of O2/O3 gas mixture to conventional measures speeds healing…which also means lower numbers of amputations (about 100,000 diabetes related amputations a year in the US alone)!
Not sure about EPA approval, I doubt it would be needed.