H[sub]2[/sub]O[sub]2[/sub]
What exactly accounts for the “boiling” appearance when you pour it on a wound? Legend says that it’s killing bacterial critters. Does it? What actually causes the bubbles?
The bubbles are the extra oxygen breaking off and floating away as O[sub]2[/sub]. It turns into water and oxygen.
I think I remember from science class that it transforms oxygen present at the wound to water and oxygen gas (or something), but essentially that by removing available oxygen it “starves” whatever bugs are there. This is why you should only use it when a wound is new as a disinfectant, as it will remove necessary oxygen from a wound in the process of healing, too.
Many bacteria contain an enzyme called “catalase” that breaks up H[sub]2[/sub]O[sub]2[/sub], but concentrations like you’d get out of a bottle would kill them pretty quickly. One of the simplest tests for finding out what kind of bacteria you have is the catalase test. You put a drop of hydrogen peroxide on a smear of cells and watch for bubbles. Pretty cool, really.
Very true. I think it’s catalase positive staphlococci. But, rarely are these guys in the wounds you’re treating.
Catalase is the secret to peroxide’s bubbling, though. It’s not bacterial catalase, but red blood cell catalase. Those little red critters are jammed with the stuff. The enzyme protects red blood cells from the harmful effects of oxygen. But more importantly, it makes peroxide bubble only where the ouch is.