**Chemical Storage**

**Storage According to Hazard Classes**

The following guidelines are provided for the safe storage of hazardous
materials in accordance with their hazard classes:

Consult the **EH&S Chemical Safety Web Page** for additional guidance.
This contains Material Safety Data Sheet and toxicological databases. An
EH&S Industrial Hygienist can also be consulted, if additional
assistance is needed.

**Acids**

o Segregate acids from reactive metals such as sodium, potassium,
magnesium, etc.

o Segregate oxidizing acids from organic acids, flammable and
combustible materials.

o Segregate acids from chemicals which could generate toxic or flammable
gases upon contact, such as sodium cyanide, iron sulfide, calcium
carbide, etc.

o Segregate acids from bases.

o See Control Procedures for Acids and Bases.

**Bases**

o Segregate bases from acids, metals, explosives, organic peroxides and
easily ignitable materials.

o See Control Procedures for Acids and Bases.

**Solvents** (Flammable and Halogenated Solvents)

o Store in approved safety cans or cabinets.

o Segregate from oxidizing acids and oxidizers.

o Keep away from any source of ignition: heat, sparks, or open flames.

o See Control Procedures for Flammable and Combustible Liquids.

**Oxidizers**

o Store in a cool, dry place.

o Keep away from combustible and flammable materials.

o Keep away from reducing agents such as zinc, alkali metals, and formic
acid.

**Cyanides**

o Segregate from acids and oxidizers.

**Water Reactive Chemicals**

o Store in a cool, dry place away from any water source.

o Make certain that a Class D fire extinguisher is available in case of
fire.

o See Control Procedures for Water Reactive Chemicals.

**Pyrophoric Substance**

o (Materials which will react with the air to ignite when exposed, e.g.,
white phosphorus.)

o Store in a cool, dry place making provisions for an airtight seal.

**Light Sensitive Chemicals**

o Store in amber bottles in a cool, dry, dark place.

**Peroxide Forming Chemicals**

o Store in airtight containers in a dark, cool, and dry place.

o Label containers with receiving, opening, and disposal dates.

o Periodically test for the presence of peroxides.

o See Control Procedures for Peroxide Forming Compounds.

**Toxic Chemicals**

o Store according to the nature of the chemical, using appropriate
security where necessary.

**Incompatible Chemicals**

Certain hazardous chemicals should not be mixed or stored with other
chemicals because a severe reaction can take place or an extremely toxic
reaction product can result. The label and MSDS will contain information
on incompatibilities.

The following incompatibility matrix and table contains examples of
incompatible chemicals:

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**Know the properties of the chemicals used**.

The chemical incompatibilities discussed below are by no means
exhaustive. As a result, it is important for laboratory personnel to
thoroughly research the properties of the chemicals they are using.
Material Safety Data Sheets (MSDSs) have sections on chemical
incompatibility. The container\'s label should also provide storage
guidelines.

**Avoid mixing incompatible waste materials**.

A number of serious laboratory accidents have occurred when people have
poured incompatible waste materials into hazardous waste containers. Use
separate waste containers for each type of waste. Consult an EH&S Waste
Generator Specialist for guidance.

**Store incompatible chemicals separately**.

Common storage problems in laboratories can lead to mixing incompatible
chemicals. The most serious of these is the storage of acids (especially
oxidizing acids) with flammable solvents. Contact of a concentrated
oxidizing acid with a flammable solvent would likely result in a fire or
an explosion. This is not an unlikely scenario in the event of an
earthquake. Storage of chemicals in alphabetical order on shelves often
results in incompatible chemicals being stored together. For example,
alphabetical arrangement could result in hydrogen peroxide (a strong
oxidizer) being stored next to hydrazine (a very strong reducer).

  -------------------------------- --------------------------------------
  CHEMICAL                         KEEP OUT OF CONTACT WITH

                                   

  Acetic Acid                      Chromic acid, nitric acid, hydroxyl
                                   compounds, ethylene glycol, perchloric
                                   acid, peroxides, permanganates

  Acetone                          Concentrated nitric and sulfuric acid
                                   mixtures, and strong bases

  Acetylene                        Chlorine, bromine, copper, fluorine,
                                   silver, mercury

  Alkali Metals                    Water, carbon tetrachloride or other
                                   chlorinated hydrocarbons, carbon
                                   dioxide, the halogens

  Ammonia, anhydrous               Mercury, chlorine, calcium
                                   hypochlorite, iodine, bromine,
                                   hydrofluoric acid

  Ammonium Nitrate                 Acids, metal powders, flammable
                                   liquids, chlorates, nitrites, sulfur,
                                   finely divided organic or combustible
                                   materials

  Aniline                          Nitric acid, hydrogen peroxide

  Arsenic materials                Any reducing agent

  Azides                           Acids

  Bromine                          Same as chlorine

  Calcium Oxide                    Water

  Carbon (activated)               Calcium hypochlorite, all oxidizing
                                   agents

  Carbon tetrachloride             Sodium

  Chlorates                        Ammonium salts, acids, metal powders,
                                   sulfur, finely divided organic or
                                   combustible materials

  Chromic Acid and Chromium        Acetic acid, naphthalene, camphor,
  trioxide                         glycerol, glycerin, turpentine,
                                   alcohol, flammable liquids in general

  Chlorine                         Ammonia, acetylene, butadiene, butane,
                                   methane, propane (or other petroleum
                                   gases), hydrogen, sodium carbide,
                                   turpentine, benzene, finely divided
                                   metals

  Chlorine Dioxide                 Ammonia, methane, phosphine, hydrogen
                                   sulfide

  Copper                           Acetylene, hydrogen peroxide

  Cumene Hydroperoxide             Acids, organic or inorganic

  Cyanides                         Acids

  Flammable Liquids                Ammonium nitrate, chromic acid,
                                   hydrogen peroxide, nitric acid, sodium
                                   peroxide, halogens

  Hydrocarbons                     Fluorine, chlorine, bromine, chromic
                                   acid, sodium peroxide

  Hydrocyanic Acid                 Nitric acid, alkali

  Hydrofluoric Acid                Ammonia, aqueous or anhydrous

  Hydrogen Peroxide                Copper, chromium, iron, most metals or
                                   their salts, alcohols, acetone,
                                   organic materials, aniline,
                                   nitromethane, flammable liquids

  Hydrogen Sulfide                 Fuming nitric acid, other acids,
                                   oxidizing gases, acetylene, ammonia
                                   (aqueous or anhydrous), hydrogen

  Hypochlorites                    Acids, activated carbon

  Iodine                           Acetylene, ammonia (aqueous or
                                   anhydrous), hydrogen

  Mercury                          Acetylene, fulminic acid, ammonia

  Nitrates                         Sulfuric acid

  Nitric Acid (concentrated)       Acetic acid, aniline, chromic acid,
                                   hydrocyanic acid, hydrogen sulfide,
                                   flammable liquids, flammable gases,
                                   copper, brass, any heavy metals

  Nitrites                         Acids

  Nitroparaffins                   Inorganic bases, amines

  Oxalic Acid                      Silver, mercury

  Oxygen                           Oils, grease, hydrogen; flammable
                                   liquids, solids, or gases

  Perchloric Acid                  Acetic anhydride, bismuth and its
                                   alloys, alcohol, paper, wood, grease
                                   and oils

  Peroxides, organic               Acids (organic or mineral), avoid
                                   friction, store cold

  Potassium                        Carbon tetrachloride, carbon dioxide,
                                   water

  Potassium chlorate and           Sulfuric and other acids
  perchlorate                      

  Potassium Permanganate           Glycerin, ethylene glycol,
                                   benzaldehyde, sulfuric acid

  Selenides                        Reducing agents

  Sodium nitrite                   Ammonium nitrate and other ammonium
                                   salts

  Sodium Peroxide                  Ethyl or methyl alcohol, glacial
                                   acetic acid, acetic anhydride,
                                   benzaldehyde, carbon disulfide,
                                   glycerin, ethylene glycol, ethyl
                                   acetate, methyl acetate, furfural

  Sulfides                         Acids

  Sulfuric Acid                    Potassium chlorate, potassium
                                   perchlorate, potassium permanganate
                                   (or compounds with similar light
                                   metals, such as sodium, lithium, etc.)

  Tellurides                       Reducing agents
  -------------------------------- --------------------------------------

From Manufacturing Chemists\' Association, Guide for Safety in the
Chemical Laboratory, pp. 215-217, Van Nostrand Reinhold, 2nd Edition.