Hydrogen peroxide + body oils = acetic acid?
Whenever I wipe down my sweaty, oily face with H2O2, I am always struck by an extremely strong smell that is exactly reminiscent of vinegar.
Am I creating acetic acid by mixing H2O2 with skin oils? If so, what exactly is the reaction?
I do not have a medical background - I got interested in this question because of my interest in Chemistry.
Googling what you said suggests two things (Again I am not a doctor - and someone with Medical background should chime in) :
1> You may be having Candida overgrowth (yeast) - some websites suggest this as a test
2> Diabetic ketoacidosis can also make your skin smell like vinegar.
I will alert the Moderator to change the thread title - so folks with medical background can comment.
H2O2 is a pretty strong oxidizing agent. It is not inconceivable that it could be oxidizing something in the sweat or (more likely) the oils secreted by the skin, into something with an acetic acid smell. I do not know enough about the composition of skin oils to be able to say what it might be, however.
Also, IANA doctor, but I am not sure that it is very safe to be frequently wiping yourself down with peroxide. It may be OK as an occasional disinfectant, but I suspect it could harm your skin if overused. The point of a disinfectant is to kill cells, and it will not discriminate between your skin cells and bacteria. Also, if, as am77494 suggests, you have a Candida infection, this may be the result of your frequent H2O2 use having killed off the beneficial bacteria that help protect your skin from such things.
I don’t think I have either yeast or Diabetic ketoacidosis, but then, I haven’t seen my doctor for quite a while.
I used to use H2O2 with no ill effect. That was several months ago. I stopped because I ran out. The cool part was that it would bleach my hair - or at least the hair near my forehead. I stopped, and I resumed some time this week, only to be hit by a strong vinegar smell. This should rule out the possibility of yeast infections resulting from overuse of H2O2. Nevertheless, I am interested in whether H2O2 is damaging to skin in the long-term.
H2O2 is not recommended for routine use as a skin or wound cleanser anymore, because, like **njtt **says, it damages your cells just as effectively as it damages bacterial cells. I’d say outright “we don’t use it anymore”, but the honest answer is that lots of us still *do *use it, especially when working First Aid in rustic conditions with no budget to speak of, but we all know we’re not *supposed *to according to the latest wound care recommendations. (See also: rubbing alcohol and Betadine)
If you like how it makes your skin feel, I’d recommend witch hazel. It’s a nice gentle astringent which will make things feel nice and clean without doing cellular damage like H2O2 does.
(I have no idea about the vinegar question. There’s not a lot I needed to retain from chemistry class, to be honest, and it would take me longer than I’m willing to devote to it to figure out the equation here.)
Hydrogen peroxide plus and enzyme called catalase from the skin produces water plus oxygen. It is an aggressive appearing reaction, but not one that should produce acetic acid.
No. At least not in any significant quantity.
The smell you are describing is a mix of things, mostly short chain fatty acids, primarily propanoic acid. I very strongly suspect peroxide’s mechanism in this situation is mainly mechanical, not chemical.
While it’s not likely to cause serious harm there are few good reasons to use peroxide directly on your skin and it can cause dermatitis if used too frequently or in too high a concentration.