Storage of Reactive Chemicals
Some chemicals react violently when they come into contact with each other and must not be stored together. Mixing of incompatible chemicals can form an explosive mixture and cause damage or injury to property and personnel. Incompatible bottles of wastes should be stored separately. The objective is to avoid accidents in the laboratory.
See table below for the possible reactions that may occur due to impropper storage of chemicals.
Substance Incompatible with Acetic acid Chromium oxide, nitric acid, perchloric acid, peroxides, permanganates, alcohol, ethylene glycol Acetic anhydride Hydroxyl-containing compounds e.g. ethylene glycol, perchloric acid Acetone Concentrated nitric acid and sulphuric acid mixtures, hydrogen peroxide Acetylene Chlorine, bromine, fluorine, copper, silver, mercury Activated carbon Calcium hypochlorite, oxidizing agents Alkali metals Water, carbon tetrachloride and other halogenated alkanes, carbon dioxide, halogens. (Do not use water or foam extinguishers for fires involving these metals Use the appropriate class D extinguisher. Aluminium All oxidizing agents, acids, alkalis, halogenated hydrocarbons, peroxides Aluminium alkyls water Ammonia, liquid or gas Mercury (e.g. in pressure gauges), chlorine, calcium hypochlorite, iodine, bromine, hydrogen fluoride Ammonium nitrate Acids, powdered metals, flammable liquids, chlorates, nitrates, sulfur, fine-particulate organic or combustible materials Aniline Nitric acid, hydrogen peroxide Arsenic materials Any reducing agent Azides Acids Bromine see chlorine Calcium oxide Water Carbon activated Calcium hypochlorite, other oxidants Chlorine Ammonia, acetylene, butadiene, butane, methane, propane, hydrogen, petroleum benzine, benzene, powdered metals
Chlorates Ammonium salts, acids, powdered metals, sulfur, fine-particulate organic or combustible substances Chromium (V1) oxide, chromic acid Acetic acid, naphthalene, camphor, glycerol, petroleum benzine, alcohols, flammable liquids Copper Acetylene, hydrogen peroxide
Cumene hydroperoxide Acids, both organic and inorganic Cyanides Acids Flammable liquids Ammonium nitrate, chromium (VI) oxide, hydrogen peroxide, nitric acid, sodium peroxide, halogens, chromic acid. Fluorine Extremely aggressive; store separately! Isolate from everything! Hydrazine Hydrogen peroxide, nitric acid, any other oxidant Hydrocarbons
butane, propane, benzene etc.
Fluorine, chlorine, bromine, chromium (VI) oxide, sodium peroxide Hydrogen fluoride Ammonia (laboratory gas or solutions) Hydrogen peroxide Copper, chromium, iron, metals and metal salts, alcohols, acetone, organic substances, aniline, nitromethane, combustible substances (solid or liquid) Hydrogen sulphide Fuming nitric acid, oxidizing gases Hypochlorites Acids, activated carbon Iodine Acetylene, ammonia (laboratory gas or solutions) Mercury Acetylene, ammonia Nitrates and nitrites Acids Nitric acid Acetic acid, aniline, chromium (VI) oxide, prussic acid, hydrogen sulfide, flammable liquids and gases Nitroparaffins Inorganic bases, amines Oxalic acid Silver, mercury, mercury salts Perchloric acid Acetic anhydride, bismuth and its alloys, alcohols, paper, wood, grease. oil, (all organics) Peroxides, organic Acids (organic and inorganic), avoid friction, store cold. Phosphorus Sulfur, compounds containing oxygen, e.g. chlorates, air, oxygen Phosphorus pentoxide Alcohols, strong bases, water Potassium Carbon tetrachloride,carbon dioxide, water Potassium chlorate see chlorate Potassium perchlorate see chlorate Potassium permanganate Glycerol, ethylene glycol, benzaldehyde, sulfuric acid Silver Acetylene, oxalic acid tartaric acid, ammonium compounds Sodium see alkali metals Sodium peroxide Methanol, ethanol, glacial acetic acid, acetic anhydride, benzaldehyde, carbon disulfide, glycerol, ethylene glycol, ethyl acetate, methyl acetate, furfural Sulphides Acids Sulphuric acid Potassium chlorate, potassium perchlorate, potassium permanganate sulphur Metals, all oxidizing agents Zinc All oxidizing agents, acids, alkalis, halogenated hydrocarbons, peroxides
Reactions of incompatible chemicals
Chemicals Stored Together Possible Reaction 1. Acetic acid & Acetaldehyde Small amounts of acetic acid will cause the acetaldehyde to polymerize, releasing heat. 2. Acids & cyanide salts or soln Generate highly toxic hydrogen cyanide gas 3. Acids & sulphide salts or soln Generate highly toxic hydrogen sulphide gas 4. Acids & Bleach Generate highly toxic chlorine gas 5. Acetic anhydride & Acetaldehyde Reaction can be violently explosive 6. Aluminum metal & ammonium nitrate A potential explosive. 7. Aluminum & bromine vapor Aluminum foil reacts with bromine vapor at room temperature and incandesces 8. Ammonia &bleach Toxic chloramine gas released 9. Ammonia vapor & bromine vapor Unstable nitrogen tribromide is formed, explosion may result. 10. Ammonium nitrate & acetic acid A mixture may result in ignition, especially if acetic acid is concentrated 11. Cupric sulfide & cadmium chlorate Will explode on contact 12. Hydrogen peroxide & acetic acid Explosion with exposure to heat 13. Hydrogen peroxide & ferrous sulfide Forms a vigorous, highly exothermic reaction 14. Hydrogen peroxide & lead II or IV oxide Violent, possibly explosive reaction 15. Hydrogen peroxide & sulphuric acid May spontaneously detonate 16. Lead perchlorate & methyl alcohol Forms an explosive mixture if agitated 17. Lead sulfide & hydrogen peroxide Vigorous, potentially explosive reaction 18. Mercury II nitrate & methanol May form mercury fulminate - an explosive 19. Nitric acid & alcohol or organic solvnts May result in fire 20. Nitric acid & phosphorus Phosphorus burns spontaneously in the presence of nitric acid Permanganate & alcohol or glycerol or organic solvents Result in fire, may be delayed. 22. Potassium cyanide & potassium peroxide A potentially-explosive mixture if heated 23. Silver salts & ammonia with strong alkali Generate explosive unstable solid. 24. Sodium nitrate & sodium thiosulfate< A mixture of the dry materials can result in an explosion. 25. Sodium metal & water Boils and form flammable hydrogen gas. 26. Potassium metal & water Generate flammable hydrogen gas.
1. Merck chemical company.
2. Chemical Safety Office, Risk Management Department, University of Vermont.
3. Hazards in the Chemical Laboratory, 4th. edition. 1986. Bretherick.