When you’re faced with a tough cleaning job, it’s easy to get frustrated — and tempting to get creative with how you combat it. But before you reach for every cleaning product under your sink and start playing chemist, please just don’t.
“People often think that if one product works, mixing it with another one will make it even better,” says Carolyn Forte, director of the Cleaning Lab at the Good Housekeeping Institute.But here’s the scary truth: “Certain products, which are safe when used alone, can sometimes cause unsafe fumes or other chemical reactions when mixed with other products,” says Nancy Bock, Senior VP of Education at the American Cleaning Institute.
And even if your ad-hoc cleaner combo isn’t dangerous or toxic, you can never be sure what effect two products can have on a surface or fabric when combined. Always read the warning and ingredient labels on cleaning products — and never mix these.
Cleaning Products You Should Never Mix
1. Drain cleaner + drain cleaner
“I would never recommend mixing two different drain cleaners or even using one right after the other,” says Forte. “These are powerful formulas, and could even explode if combined.”
Use one product according to package directions (typically, only half a bottle is needed per treatment). If it doesn’t work, don’t try another product. Instead, call a plumber, Forte says.
2. Baking soda + vinegar
We’re calling you out, Pinterest: Although these pantry staples are handy on their own (both baking soda and vinegar can help clean all over the house), skip any DIY cleaner recipe that involves this not-so-dynamic duo.
“Baking soda is basic and vinegar is acidic,” says Bock, “When you put them together you get mostly water and sodium acetate. But really, just mostly water.” Plus, vinegar causes baking soda to foam up; if stored in a closed container, the mixture can explode.
3. Hydrogen peroxide + vinegar
You may have heard that you should spray fruits or countertops with alternating mists of hydrogen peroxide and vinegar, wiping down the surface between sprays. Experts say this method is safe — but don’t mix the two products in the same container. Combining them creates peracetic acid, which is potentially toxic and can irritate the skin, eyes, and respiratory system.
4. Bleach + vinegar
The combination sounds like it’d be a powerful disinfectant, but the two should never be mixed. “Together, they produce chlorine gas, which even at low levels, can cause coughing, breathing problems, and burning, watery eyes,” says Forte.
5. Bleach + ammonia
Bleach and ammonia produces a toxic gas called chloramine. “It causes the same symptoms as bleach and vinegar — along with shortness of breath and chest pain.” says Forte. Many glass and window cleaners contain ammonia, so never mix those with bleach.
6. Bleach + rubbing alcohol
Perhaps you’ve heard of chloroform? You know, the stuff kidnappers in the movies put on rags to knock out their victims? Although it might not actually make you pass out, this combination can be irritating and toxic.
Make it a rule to never mix bleach with anything but plain water. “Even other products like window and toilet bowl cleaners can have ingredients, like acids or ammonia, that shouldn’t be mixed with bleach,” says Forte.
Read more: Good Housekeeping