Incompatible Chemicals

Many chemicals are incompatible with each other.

According to Laboratory Safety for Chemistry Students, by Robert H. Hill and David C. Finster:

Incompatible chemicals are combinations of substances, usually in concentrated form, that react with each other to produce very exothermic reactions that can be violent and explosive and/or can release toxic substances, usually as gases.

Care should be taken when handling, storing, or disposing of chemicals in combination. Below is a short list of common laboratory chemicals and the substances with which they are incompatible.

Incompatible Chemicals

Chemical  Incompatible with
Acetic acid nitric acid, peroxides, permanganates
Acetic anhydride ethylene glycol, hydroxyl-group-containing compounds
Acetone hydrogen peroxide
Ammonium nitrate acids, flammable liquids, powdered metals, finely divided organic or combustible materials
Chlorate salts, such as sodium or potassium chlorate acids, ammonium salts, metal powders, finely divided organic or combustible materials
Chlorine ammonia, butane, hydrogen, turpentine, finely divided metals
Copper hydrogen peroxide
Hydrocarbons bromine, chlorine, peroxides
Hydrogen peroxide combustible materials, copper, iron, most metals and their salts, any flammable liquid
Iodine Ammonia
Nitric acid, concentrated acetic acid, acetone, alcohol, flammable substances, such as organic chemicals
Note: There have been many explosions from inappropriate or inadvertent mixing of nitric acid with organic chemicals in waste containers.
Oxalic acid silver, mercury
Oxygen flammable materials, hydrogen, oils
Phosphorus, white air, oxygen
Potassium permanganate ethylene glycol, glycerol, sulfuric acid
Sodium (alkali metals: lithium, sodium, and potassium) arbon dioxide, water, alcohols
Sodium nitrite ammonium salts
Sulfuric acid chlorates, perchlorates, permanganates