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Question about cleaning

I came across your chemistry question website and wanted to ask a few questions. 
I have been cleaning with 3% hydrogen peroxide and 5% white vinegar.  I’d mix both, 50/50 in a 28oz spray bottle (no water). 
I just recently read that this “could” produce peracetic acid, which also “could” be harmful to eyes/lungs/skin. 
I’ve been using this formula for around 5 years. I’ve never had skin burns, but I have noticed eye/throat discomfort when scrubbing inside my shower. I thought the discomfort was due to the vinegar, but none of the symptoms  lingered. 
My questions is, should I be concerned with the heath effects of having been cleaning with this for so long? 
I do plan to talk to my dr about it, as I’m in my third trimester of pregnancy, but I wanted to ask a chemist.  I called poison control but they didn’t have much insight, especially with pregnancy. 
I truly appreciate your time and help.  
Kind regards,
Julie Moore 
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2 Replies

Re: Question about cleaning

Interesting question!  The equilibrium constant for this reaction is around 2 at 20°C:

Kinetics of Formation of Peroxyacetic Acid 

Dul’neva, L. & Moskvin, A.. (2005). Kinetics of Formation of Peroxyacetic Acid. Russian Journal of General Chemistry. 75. 1125-1130. 10.1007/s11176-005-0378-8.

If [H2O2] = 0.44 M and [acetic acid] = 0.42 M and [H2O] = 55 M, then [peracetic acid] = 0.0065 M at equilibrium 

which is just enough peracetic acid to provide some extra antiseptic activity.  It’s also enough to be irritating but I doubt it’s a serious hazard.  Perhaps others are more familiar with this hazard?

These authors also report the enthalpy of reaction as -14 kJ/mol, which allows one to calculate the enthalpy of formation of peracetic acid as -400 kJ/mol. 

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Contributor III

Re: Question about cleaning

That is a common mixture for intentional biocidal cleaning.  At those already diluted concentrations, there should be no particular harmful effect.  BUT, just as with the vinegar and peroxide (in particular) you should always take care to avoid prolonged exposure.  But as a cleaning mixture, it will remain as stable as the peroxide itself and poses no danger of explosion or corrosive action in the container.  A site with some good usage cautions - again, mostly for concentrated solutions. Peracetic Acid Uses and Hazards 

Best regards,


P.S. I also made my own formulation of 3% hydrogen peroxide and 70%propyl alcohol (50/50) as a great deodorizing cleaning spray for dogs urinating were you don't want them, and particularly for cleaning rugs and fabrics.