Cleaning Products You Should NEVER Mix


Don’t risk your health just to get your home clean. Some cleaning products are dangerous to combine or even use at the same time.

Cleaning products lined up against a blank background

Don’t Combine These Cleaning Products

When you’re faced with a stubborn mess, it’s tempting to keep trying different cleaning products until something finally works. That’s a hazardous approach, though. Sure, some combinations only cause mild itching or watering eyes, but others could knock you out or permanently damage your lungs. And some combinations of cleaning products are fatal.

1. Bleach + Vinegar = Chlorine Gas

Male hand pours liquid from a bleach bottle

The chlorine in bleach reacts with the acetic acid in vinegar to produce chlorine gas. Even brief exposure can irritate air passages and eyes. At higher levels, it causes chest pains, plus swelling and blistering of the throat, lungs, eyes, and skin. At very high concentrations, it is fatal.

2. Bleach + Ammonia = Chloramine Vapors

Backside of ginger tabby cat crawling into a hooded litter box

This combination produces chloramine gas which leads to many of the same problems described above. (If you have a cat, this is why you need to rinse the empty litter box with water before disinfecting it with a bleach solution.) Both cleaning products are powerful on their own, so you should always use good ventilation when you’re working with either one. But never use them simultaneously, or one right after the other, or the passive combination could make you very sick.

3. Bleach + Rubbing Alcohol = Chloroform

Female hand holds bottle of isopropyl alcohol used to clean laptop

Bleach contains sodium hypochlorite. Rubbing alcohol — known as surgical spirits in the UK — contains ethanol or isopropyl alcohol. The combination produces chloroform. Yep, the same stuff kidnappers on TV use to knock out their victims. Chloroform can be absorbed through the skin or inhaled and can damage your nervous system, eyes, lungs, skin, liver, kidneys, and other organs.

Incidentally, your favorite hand sanitizer contains rubbing alcohol, so don’t reach for it to clean your hands after disinfecting a bathroom.

4. Hydrogen Peroxide + Vinegar = Peracetic Acid

Bottle of hydrogen peroxide on a blue background

Actively combining hydrogen peroxide and vinegar creates peracetic acid, a highly corrosive liquid. Peracetic acid is readily absorbed through the skin and a very toxic compound that can burn the mucous membranes of the mouth, throat, and esophagus. While this reaction is sometimes used in laundry products*, where it’s heavily diluted in the wash, you shouldn’t use it for surface cleaning without rinsing well between them.

*For example, oxygenated bleach produces hydrogen peroxide when it’s dissolved in water. Adding vinegar to the same load will create peracetic acid but in such a diluted form that it doesn’t cause injury. Instead, you’ll get softer, cleaner clothes and less static cling. (Here are more reasons why you should use vinegar in your laundry.)

5. Certain Pesticides + Water = Phosphine Gas

Male hand points aerosol can of bug spray at dead cockroach on floor

Everyone hates finding bugs and spiders in their home. It’s tempting to use the strongest pesticide you can find to deal with them or to disregard the label’s warnings about use in kitchens or bathrooms. You can rinse away the danger, right? Not necessarily. Many pesticides leave a residue that produces deadly phosphine gas when combined with water. Get rid of those pests with non-toxic, natural pest control methods, or contact a professional.

6. Drain Cleaner + Drain Cleaner = Explosion

Male hand pours drain cleaner down bathroom drain

Different drain cleaners rely on different chemicals to power through grime and clogs. Some are acidic, while some are alkaline (basic). When one doesn’t work, you might be tempted to try a different product to get the drain flowing freely again. Don’t! The first drain cleaner is still in your pipes and still active, so adding a second one can cause a chemical reaction that sends corrosive ingredients spraying all over you and your home. If the first drain cleaner doesn’t work, call a professional.

How to Use Cleaning Products Safely

Using one cleaning product immediately after another can create potentially toxic results. So, it’s important that you take appropriate precautions when you clean.

Person wearing rubber gloves to wipe counter and avoid dangerous passive combination of cleaning products

Active vs. Passive Combination

Not all dangerous cleaning product combinations are the result of actively shaking or stirring the wrong ingredients together.

Passive product combination happens when you use one product immediately after another or the overspray from one product lands on a surface where another is still active. To avoid this type of passive combination, rinse cleaning products away and let the surface dry completely before changing products.

Another form of passive product combination occurs when you use different cleaners simultaneously in a room. If you’ve cleaned the toilet bowl with a bleach-based cleaner, for instance, using vinegar or ammonia-based cleaners on the seat and tank could still create a toxic cloud.

Take These Precautions

Since many product manufacturers don’t disclose what’s in their cleaning products, you should always take precautions to protect your health while cleaning. But even if you’re a fan of homemade cleaning products, you’re not entirely safe since some natural ingredients can still produce toxic vapors. Steps you can take to protect your health while cleaning:

  1. Ventilate the room. In bedrooms or living areas, open the windows and run ceiling fans, or both. In bathrooms and kitchens, run the exhaust fan. While fans won’t overcome a lethal combination, they can help speed up drying to prevent passive combinations and disburse irritating fumes.
  2. Protect your skin, even if you use natural household cleaners. Wear reusable latex or rubber gloves when you’re using cleaning products or disinfectants to prevent the products’ absorption through your skin. They’ll also shield you from coming in contact with some of the nastier bacteria that grow on household surfaces. Look for washable gloves you can launder immediately after use.

And, of course, listen to your body. If you feel dizzy, itchy, or experience burning in your eyes, throat, lungs, or skin, leave the room immediately and close the door behind you. Then stuff a towel at the base of the door to keep the fumes from spreading into the rest of your home and contact your local poison control center for advice on what steps you need to take next.

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  1. Jennie @ TheHousewifeModern says:

    Thank you, thank you, thank you. I’ve started experimenting with homemade cleaners (I have a cleaning section on my website) and my one concern about trying all these out is “do these people know what they’re talking about.” I pinned this so I can find it again! Thanks again for sharing.

    1. Katie Berry says:

      It’s smart of you to be wary. I’ve seen so many potentially dangerous cleaning mix combinations suggested online.

  2. Thank You. Great information to share. It could save someones life!

    1. Katie Berry says:

      Hope so!

  3. YoungMama says:

    Hi Katie, Do you have any info on alkaline ingredients mixed with acidic ingredients (like vinegar mixed with baking soda)? I’ve heard they cancel each other out so don’t work in a cleaner. I love your website and just ordered your 30 Days book. I learned how to clean my dishwasher from you and felt so empowered to get rid of the stink! Thank you!

    1. Katie Berry says:

      Thank you for ordering my book! I hope you find the rest of it useful, too. As for the alkaline and acidic canceling each other out, the only real info I have involves basic chemistry and is probably the exact info you have, too. I do use both vinegar and baking soda in a few of my cleansers, but in a proportion which would completely neutralize the vinegar’s acidity. In those instances, the baking soda is added solely for the purpose of providing a gentle abrasive, and in a small enough ratio to the vinegar to avoid neutralizing the vinegar’s cleaning power.

  4. I’m skeptical about using these essential oils in homemade solutions. Are they just a gimmick or really worth your time?

    1. Katie Berry says:

      Hi Patricia,
      I understand your skepticism. For the most part, essential oils work best to add fragrance either to counteract the scent of other things (like vinegar in homemade cleaning products) or for aromatherapy purposes. Lavender, for instance, is believed to have calming effects that promote sleep and relaxation.

      Some essential oils have effects beyond their fragrance. Tea tree oil is believed to have antiseptic properties and, according to the Mayo Clinic, can help treat things like nail fungus, acne, and dandruff.

      They aren’t substitutes for medicine and shouldn’t be relied upon as such. They also should not be used alone for cleaning purposes. I use them in cleaning solutions to boost the cleaning power of things like vinegar, baking soda, or other oils — and to add a nice fragrance.

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