As humans, we default to the idea that if one thing is good, then two things must be better.
No doubt, you've tried to apply this strategy to a cleaning product that you have found useful. Hey, if ___ works well, then maybe mixing ___ and ___ will scrub/polish/deodorize even better/faster!
But before you go all mad scientist, remember this: You’re mixing chemicals. And one of three things will happen when you do, says Bill Carroll Jr., an adjunct professor of chemistry at Indiana University.
No. 1: The mixture works like a dream.
“Theoretically, that could happen,” Carroll notes, “but Procter & Gamble and Lever and all the big companies have legions of chemists already working on mixing simple things together that work well. The chances that you go into your cabinet at home and randomly mix two things together that also [work like a charm] are almost nil."
(Yes, even if you aced high school chemistry.)
No. 2: Your concoction will work poorly, because you caused a chemical reaction that made the cleaning agents they contain ineffective. (More on that in a bit.)
No. 3: The worst-case scenario: “An absolutely harmful result,” Carroll says. Think: trip to the ER.
Here are four cleaning combos that, according to science, are seriously bad ideas.
1. Ammonia and bleach
If you remember nothing else from this story, remember this: The ammonia and bleach combo is a bad one.
“A surprising number of people mix ammonia and bleach, and it can be lethal,” Carroll says.
Sodium hypochlorite is the main ingredient in chlorine bleach. When it reacts with ammonia, a toxic gas called chloramine is formed.
“Just breathing it in could send you to the hospital,” Carroll notes.
And the truth is, you shouldn’t need to mix these two cleaners in the first place: They serve different purposes. "Just because you like chocolate and you like oysters doesn't mean you'll like eating them together," Carroll says.
2. Vinegar and baking soda
This cleaning combo is heralded all over the Internet as an easy, cost-effective, all-natural grime-fighting solution you can make at home. The good news: It won’t blow up your kitchen. The bad news: It doesn’t actually clean.
Remember that chemistry experiment you did in fourth grade that involved making a volcano? And how when you added vinegar (an acid) to a baking soda (a base) you got some bubbling (carbon dioxide) going on?
That’s what’s happening when you make your own cleaning solution. Except that it has zero cleaning power.
“You’re taking the mild cleaning action of vinegar and the mild cleaning action of baking soda and when you react them together, they actually cancel each other out,” Carroll explains.
The only thing this combo is good for, he adds, is if you have a clogged drain. Put a little baking soda down first, then add vinegar. The physical action of the bubbling may help break up any gunk wedged in there.
But for the most part, you’re better off using these two cleaning agents on their own: vinegar to disinfect and baking soda to clean porous surfaces and help cut grease.
3. Rubbing alcohol and bleach
Separately, they're both great at disinfecting. But together, they're a potential hazard.
Most likely to happen when rubbing alcohol meets bleach? They'll react each other away and you'll get acetone, Carroll says. That's right: nail polish remover. But don't get visions of suddenly making your own.
"In the presence of a lot of bleach, (rubbing alcohol) may drive a reaction to produce some chloroform," Carroll adds.
You know—the sweet-smelling gas that can be used to temporarily knock someone out.
"It's toxic, but not lethal in small concentrations," Carroll assures. "But why would you risk this? I see absolutely no benefit to mixing these two."
4. Vinegar and bleach
The bleach you buy in a jug at the store is sodium hypochlorite; it's strongly basic—meaning it's at the high end of the pH scale.
But if you mess up that equilibrium—say, by adding an acid such as vinegar—you can produce a toxic cloud of chlorine gas that’s actually similar to the poison gas used in World War I.
OK, so you’re probably not going to create a chemical weapon in your laundry room. But exposure to small amounts of this combo can still cause problems, Carroll says. Chlorine gas can burn your eyes, nose and throat, and can make it hard for you to breathe.
Natural cleaners aren't any less risky
Although a cleaner might be touted as “natural,” that still doesn’t mean it's safe for you to combine it with others.
“I’m not saying natural stuff is bad, but concentrated natural oils can be irritating and in some cases are allergens,” Carroll says.
Randomly mixing any cleaners carries risks, Carroll says. Your healthiest strategy: Use them as the manufacturer suggests on the package. And follow these guidelines to keep them safe when you're not using them:
Check for warning labels
As laid down by the Environmental Protection Agency, manufacturers must list potentially harmful ingredients and active disinfectants, plus first-aid tips if things do go awry.
“Read all the labels and educate yourself on the potential dangers,” advises Morgan Statt, a health and safety investigator at ConsumerSafety.org. (Check out the EPA's Safer Choice list for products they've deemed “safer” for your health and the planet.)
Store supplies safely
Your first priority is to keep cleaning supplies out of reach of small childrenor pets, Statt says. Keep them stored in a cabinet well out of reach, or use safety devices to lock kid-accessible areas.
Protect products from extreme temps
Many household cleaning products react to extreme temperature changes, so avoid storing your supplies in places that can get too hot or too cold.
Open the windows
Even if you're just using bleach, or only cleaning with ammonia, open multiple windows for ventilation.
“Proper ventilation is key to reducing just how much of these chemicals you're breathing in,” Statt cautions.