Incompatible Chemical Mixtures

Avoid Dangerous Situations

Some chemicals shouldn't be mixed together. In fact, these chemicals shouldn't even be stored near each other on the chance that an accident could occur and the chemicals could react. Be sure to keep incompatibilities in mind when reusing containers to store other chemicals. Here are some examples of mixtures to avoid:

• Acids with cyanide salts or cyanide solution. Generates highly toxic hydrogen cyanide gas.

• Acids with sulfide salts or sulfide solutions. Generates highly toxic hydrogen sulfide gas.

• Acids with bleach. Generates highly toxic chlorine gas.

• Oxidizing acids (e.g., nitric acid, perchloric acid) with combustible materials (e.g., paper, alcohols, and other common solvents). May result in fire.

• Solid oxidizers (e.g., permanganates, iodates, nitrates) with combustible materials (e.g., paper, alcohols, other common solvents). May result in fire.

• Hydrides (e.g., sodium hydride) with water. May form flammable hydrogen gas.

• Phosphides (e.g., sodium phosphide) with water. May form highly toxic phosphine gas.

• Silver salts with ammonia in the presence of a strong base. May generate an explosively unstable solid.

• Alkali metals (e.g., sodium, potassium) with water. May form flammable hydrogen gas.

• Oxidizing agents (e.g., nitric acid) with reducing agents (e.g., hydrazine). May cause fires or explosions.

• Unsaturated compounds (e.g., substances containing carbonyls or double bonds) in the presence of acids or bases. May polymerize violently.

• Hydrogen peroxide/acetone mixtures when heated in the presence of an acid. May cause explosions.

• Hydrogen peroxide/acetic acid mixtures. May explode upon heating.

• Hydrogen peroxide/sulfuric acid mixtures. May spontaneously detonate.