Chemical Storage Groups

Improper storage of hazardous chemicals may result in degradation of chemical quality, deterioration of container
labels, release of toxic gases, fire, or even explosion. As a result, local and state regulations require that chemicals be
stored according to hazard class and compatibility. A significant amount of thought, planning, and research on the
hazards associated with the chemicals being stored may be required; especially in the research laboratory
environment. Many laboratory chemicals have multiple hazards making proper storage segregation a particularly
difficult task.
The following hazard class hierarchy (based on DOT/GHS) is provided as a guide for prioritizing which hazard
classes pose the greatest risks during storage, e.g., flammability is usually a more important consideration than
toxicity. Contact the Chemical Hygiene Officer or EH&S for assistance.
Pyrophoric > Explosive > Flammable Liquid > Corrosive Acid/Base > Water Reactive >Flammable Solid > Oxidizer >Combustible >Toxic

The table below is a general reference for identifying chemical hazard classes that should be kept separated. Contact
EHS regarding storage of radioactive material. Note the manufacturer hazard codes are not always a good indicator
of chemical hazard class for segregation purposes, i.e., not all corrosives are compatible and therefore should not be
stored together. Store acetic acid with the flammables, even though it is an organic acid.
Hazard Class Pictogram Information Examples
Reactives
Phosphorus; Titanium Dichloride;
Pyrophoric Liquids or solids that spontaneously ignite upon
Tributylaluminum; Lithium Hydride;
Materials contact with air or water.
Sodium metal
Explosives are chemical compounds, that may contain TNT (Trinitrotoluene); dry Picric Acid;
Explosives nitrogen and that may detonate upon shock or Nitroglycerin; Lead Azide; Mercury
heating. Fulminate
All peroxide forming compounds must be dated and
Benzoyl Peroxide; old Ethers (e.g.,
handled in accordance with campus policy; Storage
Organic Peroxides Varies Ethyl, Methyl; Isopropyl);
location is determined by the GHS Hazard
Tetrahydrofuran; Dioxane
Classification
Flammables
Organic acids and non-flammable halogenated
Flammable and Acetone, Ethyl Ether, Petroleum Ether,
solvents can generally be stored with flammable and
Combustible Liquids Ethyl Acetate
combustible liquids (flash point > 200ºF)
Flammable solids may also be reactives; think Picric Acid powder; Sodium; Calcium
Flammable Solids
carefully prior to placing in storage location. Carbide
Corrosives
Oxidizing and Mineral acids (pH is usually  2)
(DOES NOT include organic acids). Perchloric acid Hydrochloric, Perchloric, Sulfuric,
Inorganic Acids
should be stored inside a glass or porcelain secondary Phosphoric, Nitric Acid
container.
Sodium Hydroxide, Potassium
Inorganic Bases Caustic liquids and solids with pH  12.5
Hydroxide, Ammonium Hydroxide
May be stored with flammable and combustible
Propionic Acid, Formic Acid, p-
Organic Acids liquids. DO NOT store with oxidizers or mineral and
Toluenesulfonic acid
oxidizing acids
May be stored with flammable and combustible
Organic Bases liquids. DO NOT store with oxidizers or mineral Triethylamine, Diisopropylethylamine,
bases
Nitrates, Nitrites, Permangenates,
Oxidizers DO NOT STORE near organics
Perchlorates, Chlorates, Chlorites
May be included in other storage classes but kept
separate from low hazard materials. These materials Teratogens, Carcinogens, Cyanides,
Highly Toxic should be easy to identify as highly toxic. Included in Formaldehyde, Methyl-nitrosourea,
this class are chemicals on the “Select Carcinogen Acrylamide
List” and those with specific regulatory requirements.
Agars, Sodium Chloride, Potassium
Low Hazard Materials commonly used with no special hazards
Chloride, Glycerine, Amino Acids
 Storage Group Examples
When space allows, storage groups should be kept in individual cabinets. The following scheme
can be used when cabinet space is limited.

Please contact EH&S at 459-2553 for storage of: