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human
What is happening when hydrogen peroxide bubbles when it come in contact with an infected area?

I recently got my ears pierced and due to me not keeping up with cleaning them as much as I'm supposed to they have gotten infected. To help clear up the infection I dipped them in some hydrogen peroxide. After that they began to bubble. I assume that that just means its killing the bacteria but just to be safe I thought I'd ask that smart people of AskScience.
gpt
Great question!

Blood and cells contain an enzyme called catalase. Since a cut or scrape contains both blood and damaged cells, there is lots of catalase floating around.


When the catalase comes in contact with hydrogen peroxide, it turns the hydrogen peroxide (H2O2) into water (H2O) and oxygen gas (O2).
Catalase does this extremely efficiently -- up to 200,000 reactions per second. The bubbles you see in the foam are pure oxygen bubbles being created by the catalase. Try putting a little hydrogen peroxide on a cut potato and it will do the same thing for the same reason -- catalase in the damaged potato cells reacts with the hydrogen peroxide.


Hydrogen peroxide does not foam in the bottle or on your skin because there is no catalase to help the reaction to occur. Hydrogen peroxide is stable at room temperature.