Hydrogen peroxide is cost-effective, widely available, and promoted by many as an effective disinfectant. Along with baking soda and vinegar, it’s one of my three favorite natural green cleaners. I’ve counted on it for years!
Imagine my surprise when I received an email asking me to rescind my information about the hydrogen peroxide/vinegar duo for sanitizing countertops. I was heartbroken at the thought of having to rescind/delete one of my favorite posts on natural kitchen cleaners, one that readers reference time and time again.
So before I clicked ‘delete’ on information I’ve always considered to be helpful, I decided to do a little research and dig into the science. Is hydrogen peroxide a disinfectant? I was bound and determined to settle the matter – once and for all.
The Question – Does Hydrogen Peroxide Kill Germs?
Here is an excerpt from the well-meaning email:
In a former job, I sold industrial chemicals and as a part of that job, taught sanitation and disinfection seminars to professional cleaning staffs.
I must caution you that your suggestion about using vinegar and hydragen peroxide will not kill germs. Germ killing is strictly regulated by the EPA. If you say that a solution will kill germs it has to be tested and certified by the EPA. Aside from chlorine bleach there is a hospital grade disinfectant that is highly concentrated to be mixed at 400 ppm (parts per million) of ammonium quartenary. You can also buy this premixed at janitorial supply houses. It is not toxic in its dilute forms. There is also an iodine phenolic solution that will work but is mainly used in surgery and not in home cleaning. There are even test strips to determine the level of ammonium quarternary to make sure that it is at 400 ppm. Anything else is just “feel good” remedies which are quite often dangerous, but at the very least they don’t disinfect which is dangerous if you think it has been disinfected.
I have a science major including chemistry and micro biology. You should discourage and not print home made recipes for cleaning products because it will cause totally unqualified people to experiment with chemicals which is highly dangerous.
My quick response to him:
What about tea tree oil as a disinfectant, and rubbing alcohol? Is it just an old wives’ tale when people sterilize their needle for getting out a splinter with rubbing alcohol? There have to be more than 4 things in the world that will kill bacteria. What is hydrogen peroxide good for, then?
As to sterilizing a needle, the correct answer is with direct heat with a match or over the stove. It is true that alcohol will kill some germs but is not a broad spectrum disinfectant. Peroxide oxygenates the wound but if you go to a hospital or urgent care with a cut that needs to be stitched, they will use the iodine phenolic that I previously mentioned. It is for human contact, the ammonium quartenary that I mentioned is for use on hard surfaces only.
Well harumph, thought I. The more I thought about it, the more I started to wonder if this fella’s information could possibly be correct. His claims weren’t just invalidating the hydrogen peroxide and vinegar combo – what about the claims plastered all over alcohol-based waterless hand sanitizers? Surely this couldn’t be completely accurate.
The Authorities on Disinfection Claims
When I do research, I like to go straight to the most credible sources I can find. PubMed, the CDC, the EPA – no offense to the author of the email above, but I like to get my information straight from the horse’s mouth, so to speak.
Sources that say an alcohol-based sanitizer will kill germs:
Sources that say hydrogen peroxide is a disinfectant:
- The EPA includes hydrogen peroxide on its list of Disinfectants for Use Against SARS-COV-2
- The CDC includes hydrogen peroxide in its general disinfection and sterilization guidelines.
- The CDC defers to the EPA list linked above in a special set of recommendations created for the cleaning and disinfection of US Households with known or suspected coronavirus infection.
- Here’s some information from Consumer Reports – Common Household Products that can Destroy the Novel Coronavirus.
- Yet another mention in an article from NBCNews.
- The United States Food and Drug Administration (FDA) has classified hydrogen peroxide as a Low Regulatory Priority (LRP) drug for use in controlling fungus on fish and fish eggs. (from Wiki)
Research even shows that vinegar and hydrogen peroxide sprayed separately is “more effective at killing …Salmonella, Shigella, or E. coli bacteria than chlorine bleach or any commercially available kitchen cleaner.”
I’ve seen this study quoted many, many places, but here’s the trick: the two solutions MUST be in separate containers and sprayed one after the other. Combining them in the bottle makes the solution ineffective.
I always try to let stuff like this dry on the surface, because I believe that’s where most of the sanitizing action happens. It takes time to wage war on bacteria. When you’re talking stuff like fish and raw chicken, it’s worth the wait.
The Verdict – Is Hydrogen Peroxide a Disinfectant?
It seems to me that all the data points to yes. While I can see my emailer’s information was likely sent from a place of good intention and his information may be used in hospital settings, I will continue using hydrogen peroxide to kill germs in my house.
In fact, I love that whether I do my “two bottle” magic with vinegar or not, a review of 22 studies found that just 0.5% hydrogen peroxide inactivates viruses. Regular household peroxide is a 3% concentration, so when I dilute it 50/50 with water, that’s a 1.5% solution, even stronger than totally necessary (but won’t bleach your clothes).
I’m a fan!
RELATED: Best dishwashing practices to kill germs.
How to Use Hydrogen Peroxide to Kill Germs in the Home
Here are a few practical points to keep in mind when using hydrogen peroxide –
- Must keep it in an opaque bottle! A small spray bottle sprayer directly on the brown peroxide bottle works nicely. Look for the large peroxide bottle if you have a standard size sprayer, or grab these nice glass ones.
- Do not mix peroxide with any other cleaner. It is safe to combine peroxide’s disinfecting power with vinegar, but they must be sprayed separately.
- Hydrogen peroxide should only be used on inanimate objects like glass, metal, and plastic.
- The CDC recommends first cleaning the surface with soap and water before using hydrogen peroxide or any other disinfecting solution.
- Hydrogen peroxide should be left on the surface for at least five minutes and up to 60 minutes before wiping clean or drying to give it enough time to kill germs.
- Hydrogen peroxide can be damaging to some surfaces, so proceed with caution. (Although to be fair, I’ve been using this for over a decade regularly on allllll sorts of surfaces, and I’ve never seen a speck of damage.)
- Don’t use peroxide on cuts as the first line of defense – it oxidizes the cells and makes healing more difficult (this is from a nurse at my child’s pediatrician’s office). “Whoops” from me! I was absolutely relying on H2O2 as a “safe” and painless cut cleaner. Just soap and water, they say. Alrighty then…