A co-worker just said something I’ve heard many times before: The bubbles that form when you put peroxide on an open wound are all the tiny little germs dying. Alcohol kills germs too, but you don’t get that foaming action with it (although you do get a real nice burning sensation-- maybe it’s the dying germs getting their last revenge).
What is actually causing the peroxide to foam?
Hydrogen peroxide, H[sub]2[/sub]O[sub]2[/sub] breaks down into water and oxygen. The bubbles are oxygen. The breakdown is accelerated by enzymes, peroxidases, found in saliva.
Why would it break down in an open wound that hasn’t been licked?
There are other enzymes that also cause peroxide to break dowm. Catalase being the one I deal with most often.
Cells contain peroxidases too. When you bust them, it gets out. Metal ions, iron, copper, manganese etc. also catalyze the breakdown.
So the foam is from the guts of the cells (due to the wound) interacting with the Peroxide?
If I pour some on clean intact skin it shouldn’t react then?
Now, the burning question; What if some got poured on poop? Would it bubble and foam up?
Pretty much, although if you’ve been sweating or have dirt on you, you might get a reaction.
Poop contains loads of bacteria, which produce peroxidases, so it’ll foam like it’s 1999.
Ah, GQ— where you can find peroxide specialists.
I think I’ll let my co-workers continue to believe the bubbles are germs drowning. Who wants to be known as a know-it-all? Plus, I doubt they’d believe me anyway.
Thanks guys.
Ooh, great! my roots need a touch-up!
What?
'kay… so is it or is it not a reliable disinfectant?
I’ve had some hydrogen peroxide get on my very dry but intact skin and somehow it works it’s way under my skin and it burns. Perhaps there is a tiny break in the skin that I just can’t see but it actually happens a lot and I hate it.
If you can get a hold of a largish quantity of fresh blood (I saw this done with pig blood,) mixing the blood and H2O2 will produce a rather spectacular foamy result.
Reading this gave me an Aha! moment. Just last week, I asked my dental assistant if I should rinse with water after I use hydrogen peroxide. She said no and, somewhat puzzled, asked why I was asking. I didn’t want to say, “Because it’s a chemical.” (I tend to be wary of the stronger ones) so I lamely said, “Because of the bubbles.” Now I know that it’s just water and oxygen, not something akin to battery acid. (Well, not quite battery acid, of course.) Thanks for fighting my ignorance, Squink!
Particularly red blood cells (Erythrocytes) contain loads of catalase. As a side reaction of oxygen transport by hemoglobin, superoxide radicals are produced, if an oxygen molecule steals an electron from the heme iron. To protect the cell, superoxid dismutase converts superoxide radicals to H2O2, catalase converts the H2O2 to O2 and water
Further to Scubaqueen at Post #10. Just what does hydrogen peroxide do which makes it a disinfectant? IOW, why does the bugs hates it [sic]?
The contents of a molecule has very little to do with how it will react with your body. Increasing or decreasing the number of atoms in a substance can greatly change its chemical properties, causing things to change from being food to being explosive acid and still being composed of just basic “safe” elements.
For example, take 2 H2 + O2 -> 2 H2O, hydrogen and oxygen reacting with each other to form water: adding water to a fire will extinguish the fire. Adding hydrogen and oxygen may result in a big explosion!
Hydrogen peroxide is not necessarily safe stuff, but it is safe in household concentrations. At higher concentrations it can be very dangerous stuff. It is highly reactive and explosive.
If you pour it on what the poop made burn, yes, it will bubble and foam.
Uh, I have a related question: Why does hydrogen peroxide have a distinct smell? It’s more noticeable after applying it to the skin, but it seems to me that it has a slight smell even when it’s in the bottle.