What should you never mix with hydrogen peroxide?

Never Mix Hydrogen Peroxide and Vinegar

It might seem harmless—after all, both hydrogen peroxide and vinegar are common household items often praised for their cleaning power. But when mixed together, they create a chemical reaction that can be dangerous. Combining hydrogen peroxide with vinegar produces peracetic acid, a highly corrosive substance that can irritate the skin, eyes, and respiratory system even in small concentrations.

This reaction happens quickly, and the resulting compound is far more aggressive than either of its components. Peracetic acid is used in industrial settings for sterilization and disinfection, but only under controlled conditions with proper safety measures. At home, exposure to this substance—especially in poorly ventilated areas—can lead to coughing, shortness of breath, or even chemical burns on contact.

Many people assume that mixing natural or common cleaners boosts their effectiveness. In reality, it often does the opposite—creating hazards instead of solutions. The U.S. Environmental Protection Agency and poison control centers consistently warn against mixing cleaning agents, especially those containing hydrogen peroxide or acids like vinegar.

For safe and effective cleaning, it's best to use one product at a time and rinse surfaces thoroughly between applications. Stick to label instructions and avoid experimentation—what works in a lab won’t necessarily be safe in your kitchen or bathroom.

In short: keep the vinegar and hydrogen peroxide in separate bottles. Your health—and your home—will thank you.