When most of us think of the word “disinfectant,” we imagine store-bought options that often contain EPA-registered pesticides and can trigger asthma-like symptoms. (1). However, there’s a cheap, non-toxic, effective option that you probably already have on hand right now – hydrogen peroxide.
According to the Centers for Disease Control, 3% hydrogen peroxide (the kind commonly found on store shelves) “is a stable and effective disinfectant when used on inanimate surfaces.” However, just like with my homemade dishwasher detergent, there’s a right way (and a wrong one) to use it.
In this article we’ll dive into:
- What hydrogen peroxide is
- The difference between cleaning and disinfecting
- What NOT to mix with hydrogen peroxide
- How to use it properly for cleaning and disinfecting around the house
What is hydrogen peroxide?
Chemically speaking, hydrogen peroxide is identical to water except that it has one extra oxygen atom (H₂O₂). This extra atom is what makes it a powerful disinfectant. Here’s how:
- When hydrogen peroxide is sprayed on a surface, the extra oxygen atom breaks away and attacks “membrane lipids, DNA, and other essential cell components” of microbes, says the CDC. (2) This reaction is called oxidation.
- Once the all the oxygen atoms detach from the original molecules and do their thing, the remaining molecules degrade safely into H₂O, aka water.
It’s available in several different strengths. The kind you see in brown bottles on store shelves is usually a 3% hydrogen peroxide solution, but there are also higher concentrations like 35% food grade hydrogen peroxide. All the uses discussed in this article are for the 3% concentration.
Why use hydrogen peroxide for cleaning and disinfecting?
Hydrogen peroxide is the active ingredient in many store-bought disinfectants and cleaning products, and for good reason:
- It’s odorless
- It’s affordable
- It degrades into water, making it safe for the environment, use around children, pets, etc.
According to the CDC, “Hydrogen peroxide is active against a wide range of microorganisms, including bacteria, yeasts, fungi, viruses, and spores .” (2) Specifically, it has been found to kill E. coli, Streptococcus species, H1N1 virus, and norovirus. (2) (3) (4)
Something to keep in mind, though, is that hydrogen peroxide works more slowly than other disinfectants, so as we’ll discuss later you’ll want to increase the contact time (the amount of time it sits on a surface).
Cleaning Vs. Disinfecting: What’s the difference?
Although they’re often used interchangeably, cleaning and disinfecting are actually different:
- Cleaning with soap and water, vinegar, or baking soda helps to remove debris, oil, grime and some pathogens from surfaces
- Disinfecting kills pathogens on surfaces
Disinfection works best when surfaces are free of debris, so the two processes work together. Depending on the way it’s used, hydrogen peroxide can help with both aspects.
14 Hydrogen Peroxide Uses for Cleaning & Disinfecting
We’re all familiar with the way hydrogen peroxide foams when applied to cuts and scrapes – the foaming process is a sign that it’s killing bacteria. Unfortunately it also kills healthy cells that are needed for repair and may slow down recovery while increasing scarring, so it’s no longer recommended as an antiseptic by many health professionals.
On the flipside, it makes a great disinfectant, natural bleach alternative, and more, so maybe it’s time to move it from the first aid kit to your cleaning supply stash. Here are my favorite ways to use it around the house:
1. Disinfect Doorknobs, Countertops & Other Frequently Touched Surfaces
Hydrogen peroxide degrades when exposed to light and heat, so it’s best to keep it in the brown bottle it comes in and store it in a cool place. To use, I just put a spray nozzle directly on the bottle and spritz it on hard, non-porous surfaces such as countertops and doorknobs.
However, if you can’t find a nozzle to fit your bottle, you can pour it into a different spray bottle. Keep in mind that unless your bottle filters light completely (or nearly so), you’ll want to store it in a cool, dark cabinet between uses so that it doesn’t lose potency. Even if you’re using the original brown bottle you’ll want to store it in a cool area.
Now that we’ve talked about storage, let’s talk about how to apply it. When researchers have looked at the effectiveness of hydrogen peroxide at killing specific organisms, they’ve used different concentrations and contact times (aka the amount of time the hydrogen peroxide is left on the surface). Three percent is generally considered sufficient, but depending on the organism the contact time can range from a couple of minutes to half an hour.
Here’s the approach I use:
- Make sure the surface is clean – no grease, debris, etc.
- Spray the surface with enough 3% hydrogen peroxide to keep it visibly wet for 3-4 minutes
- Let the surface air dry if possible. If you have to wipe it down, wait at least 5-10 minutes.
When I use the air-dry method, I consider a surface disinfected after 30 minutes.
Two important notes:
Hydrogen peroxide should never be mixed with vinegar because it creates peracetic acid, a toxic compound that can corrode surfaces and irritate skin, eyes and the respiratory tract.
However, when used properly hydrogen peroxide and white vinegar are a dynamic duo that work more effectively in tandem than separately – click here for my DIY Vinegar + Peroxide All-Purpose Cleaner Recipe.
Also, hydrogen peroxide is safe for use on granite occasionally, but it is not recommended for continual use. (6) That’s because it is slightly acidic and can break down the finish. Some experts say it can be used occasionally on light colored marble, but may discolor darker marble. (7)
Undiluted 70% rubbing alcohol is less acidic than water and is effective against certain microorganisms, says the CDC and Consumer Reports, so that’s another option to consider. (2) (5) They note that it’s generally safe for most surfaces although it may discolor some plastics.
Also, although it’s a cleaner rather than a disinfectant, if you have granite counters this recipe might be helpful.
2. Kill Mildew
Spray directly on windowsills, shower curtains, and other area that are prone to mildew, let sit for 15 minutes, then scrub the area.
3. Whiten Grout
There are a couple of different ways to whiten grout with hydrogen peroxide. One is to spray the grout, let it sit for about 15 minutes, and then scrub it with an old toothbrush.
Another option is to make a runny paste using hydrogen peroxide and baking soda. Pour it on the grout and allow it to bubble up. It will act somewhat like oxygen bleach, and the bubbling will help to lift some stains. After the bubbling is over, sprinkle some more baking powder on the grout and give it a good scrub with an old toothbrush. This method works well for removing soap scum, too.
4. Make Mirrors, Windows & Glass Shine
Spray 3% hydrogen peroxide, allow it to sit for 10-15 seconds, and then wipe with a cloth for a streak-free finish. Here’s another recipe for streak-free window cleaner that works well, too.
5. Deep Clean Cutting Boards
Hydrogen peroxide can be especially helpful when it comes to cutting boards, which often have little grooves that can harbor bacteria and other pathogens. After scrubbing with hot water and soap, pour hydrogen peroxide over the top of the cutting board and use a clean sponge to distribute it evenly. Let it bubble for 10-15 minutes, then rinse clean. If desired, follow with vinegar as described in this article.
Note: If you have a fancy cutting board made from a special wood, keep in mind that hydrogen peroxide may fade or bleach the finish. I use this method on wood cutting boards that aren’t fancy in any way, so I don’t mind.
6. Soak Kitchen Sponges & Shower Loofahs
Soak in a 50/50 mixture of hydrogen peroxide and filtered water for 10-15 minutes, then rinse thoroughly.
7. Make a Shower Spray
I keep a bottle of hydrogen peroxide (fitted with a nozzle) in my bathroom to use as an after-shower spray. It keeps mold and mildew from forming, and makes weekly cleaning a lot easier.
8.Sanitize & Deodorize Trash Cans
If you’ve cleaned your trash can and it still seems a little funky, you can place some baking soda in the bottom to absorb odors. Since baking soda can’t easily be applied to the walls, I suggest spraying the inside walls of the trash can with hydrogen peroxide and allowing to air dry. If the trash can is plastic or another material that won’t be affected by hydrogen peroxide (list below), you can spray the outside, too.
9. Disinfect Kids Toys & Play Areas
Since it breaks down into water, hydrogen peroxide is a great option for toys, play tables, and other things kids use regularly. Spray enough hydrogen peroxide to keep the surface visibly wet for 3-4 minutes, then allow to air dry. Don’t use it on cardboard or other surfaces that will be damaged by moisture.
10. Stain Remover
I’ve used this homemade stain remover with hydrogen peroxide on ketchup, grass stains, oil stains, blood stains and those mystery stains you don’t notice until something has already been washed and dried.
11. Wipe Down The Fridge
Because it’s non-toxic, hydrogen peroxide is a great option for food surfaces like refrigerator shelves. Just spray, let it sit for 5-10 minutes, then wipe clean.
12. Soak Toothbrushes & Thermometers
I fill shot glasses (that my family uses to take fire cider) with 3% hydrogen peroxide and soak the toothbrush head or thermometer tip in the glass for 10-20 minutes before allowing to air dry. This method is helpful for cleaning retainers, too.
13. Bleach Alternative for Fabrics
The CDC says that hydrogen peroxide can be used in concentrations of 3-6% to disinfect fabrics, but it’s important to note that it may cause fading or discoloration so I would only use it on white fabrics. (That’s why I dilute it in my stain remover recipe.)
The upside is that it’s a natural bleaching agent, making it perfect for whitening and brightening laundry. Here’s how to use it as an alternative to bleach for laundry.
14. Reusable Grocery Bag, Lunch Box, & Cooler Sanitizer
Spray it on anything that comes into contact with food and allow to air dry.
Cautions When Cleaning With Peroxide
There are two important things to be aware of before using hydrogen peroxide as a cleaner or disinfectant:
Never mix it with vinegar. When combined with vinegar it creates paracetic acid, a toxic compound that can corrode surfaces and irritate skin, eyes and the respiratory tract.
However, when used properly hydrogen peroxide and vinegar are a dynamic duo that work more effectively in tandem than separately – click here for my DIY Vinegar + Peroxide All-Purpose Cleaner Recipe.
Test surfaces before using. Hydrogen peroxide should not be used on copper or brass because it reacts with them. If you’re unsure about whether it is appropriate for a specific surface, do a patch test before using.
How To Know If Your Hydrogen Peroxide Is Still Good
When stored in its original brown bottle in a cool area, hydrogen peroxide has a shelf life of about six months once it’s opened. After that it isn’t harmful, it’s just not necessarily effective.
To test if your hydrogen peroxide is still good, you can place a sliver of potato in a small bowl and pour hydrogen peroxide over it. If it fizzes, it’s good.
What’s your favorite way to clean with hydrogen peroxide?
1. California Department of Public Health (2017) Disinfectants and Work-Related Asthma
2. Centers for Disease Control and Prevention (2008) Chemical Disinfectants
3. Centers for Disease Control and Prevention (2010) 2009 H1N1 Flu (“Swine Flu”) And You
4. Romain, Alana (2020) Does Hydrogen Peroxide Kill Norovirus?
5. Consumer Reports (2020) Common Household Products
6. Countertop Specialty. Cleaning Granite Countertops With Hydrogen Peroxide
7. Sefa Stone (2016) 12 Marble Cleaning Hacks You Probably Don’t Know