Why should hydrogen peroxide never be mixed with bleach?

• A. It creates a potentially deadly gas
• B. It neutralizes the bleach
• C. It loses its whitening effect
• D. It becomes a harmless liquid

Answer: (A)

Mixing hydrogen peroxide with bleach brings together two powerful oxidizers, which triggers a reaction that releases chlorine gas. Chlorine gas is a toxic irritant that can burn the eyes, throat, and lungs, and it can be dangerous to breathe even in relatively small amounts, especially in poorly ventilated spaces. So the key concern isn’t that cleaning power is lost or that the liquids just mix harmlessly; it’s that a dangerous gas is produced. The other ideas miss the real danger: the reaction can release a hazardous gas rather than just neutralizing or simply becoming a harmless liquid.