General General Considerations for Chemical Storage
Carefully read the label before storing a hazardous chemical. The MSDS will also provide any special storage information and incompatibilities.

Do not store unsegregated chemicals in alphabetical order or incompatible chemicals in close proximity to each other. The amount of space that can be placed between different chemical classes depends on the amount of storage area available in the lab suite. Do not segregate chemical classes into separate rooms unless they will only be used in that room. Segregation that disrupts normal work flow or requires more frequent transport of chemicals between labs will increase the probability of a chemical spill. Use common sense in planning chemical storage areas.

Store dry reagents, liquids reagents and solutions and compressed gases in separate areas. Within each of these chemical forms segregate into hazard classes.

Segregate dry reagents as follows:

• oxidizing solids
• flammable solids
• water reactive solids
• all others solids

• acid liquids
• caustic liquids
• oxidizing liquids
• perchloric acid solutions
• flammable or combustible liquids
• all other liquids

• toxic gases
• flammable gases
• oxidizing and inert gases

Use approved storage containers and safety cans for flammable liquids. Use spill trays under containers of strong corrosive reagents. Do not store liquids above eye level.

Dispose of old chemicals promptly. See waste disposal section of this manual.

Ensure that all containers are properly labeled. For more information on chemical storage, contact your supervisor, instructor, or EHRS.

All storage cabinets located in hallways must be placarded with the name of the owner and also with identification of the cabinets contents. This information is critical for emergency personnel who may respond in the evening The principal investigator must complete a Hallway Storage Sign Form (Appendix J) for each cabinet located in a hallway.

The storage of flammable and combustible liquids in a laboratory, shop, or building area must be kept to the minimum needed for research and operations. When large quantities of flammable liquids are present in a lab they must be stored in a flammable-liquids storage cabinet. Flammable-liquids storage cabinets are not intended for the storage of highly toxic materials, acids, bases, compressed gases or pyrolytic chemicals.

1. No more than 60 gallons of a Class I flammable liquids (flash point below 100°F) or Class II combustible liquids (flash point between 100 to 140°F) may be stored in a flammable-liquids storage cabinet.
2. No more than 120 gallons of a Class III combustible liquid (flash point between 140°F and 200°F) may be stored in a flammable-liquids storage cabinet.
3. Storage cabinets shall be designed and constructed to limit the internal temperature to not more than 325°F when subjected to a 10-minute fire test using the standard time temperature chart set forth in NFPA 251.
4. All flammable-liquids cabinets shall be labeled in conspicuous letters "Flammable - Keep Fire Away."
5. Storage cabinets shall be constructed of at least No. 18 gauge sheet iron and shall be double walled with 1-1/2 inch air space. Joints shall be riveted, welded, or made tight by some equally effective means. The door shall be provided with a three point lock, and the door sill shall be raised at least 2 inches above the bottom of the cabinet.
6. All flammable liquid storage cabinets must be grounded. A ground cable of 3/8" copper braid or a 12 gauge copper conductor can be used. The ground must be tested and resistance to ground cannot exceed one megohm. The grounding cable must be connected to a building structural member or an electrical building ground. Due to increased use of plastic piping, (which breaks the ground) water pipes must not be used for grounding.
7. The NFPA Technical Committee on General Storage of Flammable Liquids considers that providing vents to storage cabinets reduces the limited fire protection provided by such cabinets because a single walled duct will transmit heat faster than a double-walled cabinet. Ventilation of storage cabinets is recommended only when highly odoriferous conditions exist. Ventilation requires a steel duct and an appropriate exhaust fan discharging to a appropriate location outside the building.
8. All chemical storage in cabinets must be compatible.

Storage of flammable liquids outside of a storage cabinet should avoided when possible. Flammable liquids that are not in use should be stored in an appropriate cabinet.

1. The maximum quantity of flammable liquids permitted to be stored in a laboratory outside of a flammable-liquids cabinet varies depending on the design of the research building. The maximum permissible quantity will be determined on a case-by-case basis by the Offices of Fire and Occupational Safety, and Environmental Health and Radiation Safety.
2. Flammable liquids should not be stored in a refrigerators unless it is UL approved for flammable liquid storage. Storage of flammable liquids in household grade refrigerators is a fire hazard. Household grade refrigerators should be labeled: "No food or flammable liquid storage".

Stability refers to the susceptibility of the chemical to dangerous decomposition. Ethers, and olefins form peroxides on exposure to air and light. Since these chemicals are packaged in an air atmosphere, peroxides can form even though the containers have not been opened. Write the date received and date opened on all containers of ether.

Unless an inhibitor was added by the manufacturer, closed containers of ether should be discarded after 1 year.

Open containers of ether should be discarded within 6 months of opening. In the Department of Chemistry, refilled ether cans should be so labeled.

The label and MSDS will indicate if a chemical is unstable.

The following are examples of materials that may form explosive peroxides:

Shock sensitive refers to the susceptibility of the chemical to rapidly decompose or explode when struck, vibrated or otherwise agitated.

Some chemicals become increasingly shock sensitive with age. Write the date received and date opened on all containers of shock sensitive chemicals. Unless an inhibitor was added by the manufacturer, closed containers of shock sensitive materials should be discarded after 1 year. Open containers of shock sensitive materials should be discarded within 6 months of opening.

The label and MSDS will indicate if a chemical is shock sensitive. Wear appropriate personal protective equipment when handling shock sensitive chemicals.

Table 1 lists materials that can be shock sensitive.

acetylides of heavy metals ammonium perchlorate copper acetylide dinitroglycerine dipicryl sulfone fulminate of silver germane hexite hyrazoic acid lead salts mercury tartrate nitrated polyhydric alcohol nitroglycol organic amine nitrates picratol potassium nitroaminotetrazole sodatol syphnic acid trinitroanisole trinitronaphthalene tritonal	aluminum ophorite explosive ammonium picrate cyanuric triazide dinitrophenol dipicylamine fulminating gold guanyl nitrosamino guanyltetrazene hexanitrodiphenyl-amine lead azide lead styphnate mononitrotoluene nitrogen trichloride nitroguanidine organic nitramines picric acid silver acetylide sodium amatol tetrazene trintrobenzene trinitrophenetol urea nitrate	amatol ammonium salt lattice cyclotrimethylenetrinitramine dinitrophenolates erythritol tetranitrates fulminating mercury guanyl nitrosamino guanylidene hydrazine hexanitrostilbene lead mannite magnesium ophorite nitroaminotetrozole nitrogen tri-iodide nitroparaffins organic peroxides picryl chloride silver azide sodium dinitro-ortho-cresolate tetranitrocarbazole trinitrobenzoic acid trinitrophloro-glucinol
ammonal butyl tetryl cyclotetramethylenetranitramine dinitrophenyl hydrazine explosive mixtures fulminating platinum guanylidene hexogen lead mononitro-resorcinate mannitol hexanitrate nitrated carbohydrate nitroglycerin nitronium perchlorate picramic acid picryl fluoride silver styphnate sodium nitrate-potassium explosive mixtures tetrytol trinitrocresol trinitrotoluene	ammonium nitrate calcium nitrate dinitroethyleneurea dinitrotoluene fulminate of mercury compounds gelatinized nitrocellulose heavy metal azides hydrazinium nitrate lead picrate mercury oxalate nitrated glucoside nitroglycide nitrourea picramide polynitro aliphatic compounds silver tetrazene sodium picramate trimonite trimethylolethane trinitroresorcinol

* This list is not all inclusive. Review the material safety data sheet for reactivity information concerning the chemicals you use.

All locations within the laboratory where acutely toxic, carcinogenic, or reproductive hazards are stored should be demarcated with designated area caution tape. Preprinted tape is available from EHRS (see Appendix G), the Cell Center or the Chemistry stockroom or the lab worker may write designated area on yellow tape and use that. Storage areas should be segregated from other chemical storage as space permits. Do not segregate chemicals into separate rooms. This will increase the need to transport the chemical and increase the risk of a spill.

Carefully read the label before using or storing compressed gas. The MSDS will provide any special hazard information. Always use the minimum size cylinder required to perform the work.

Cylinders of compressed gases must be handled as high energy sources. When storing or moving a cylinder, have the cap securely in place to protect the stem. Use suitable racks, straps, chains or stands to support cylinders. Compressed gas cylinders pose a crush hazard to hands and feet.

Do not expose cylinders to temperature extremes.

Do not store cylinders or lecture bottles with the regulator in place. If the regulator fails, the entire contents of the gas cylinder may be discharged.

Always use the correct regulator. Do not use a regulator adapter. Oil or grease on the high pressure side of an oxygen cylinder can cause an explosion. Do not lubricate an oxygen regulator.

Cylinders of toxic, flammable or reactive gases should be stored and used in a fume hood or with local ventilation.

Never bleed a cylinder completely empty. Leave a slight pressure to keep contaminants out.

Always wear safety glasses when handling compressed gases.

For more information, contact your supervisor, instructor, or EHRS.

The storage of flammable gas cylinders is limited to two (2) type 1 (10" x 50") cylinders per 500 square feet of unsprinklered laboratory space.

Liquefied flammable gas containers should be limited to two (2) 9" x 30" cylinders per 500 square feet of unsprinklered laboratory space or three (3) 9" x 30" cylinders per 500 square feet of sprinkled laboratory space.

The transportation of hazardous chemicals in laboratory buildings provides the greatest potential for chemical exposure to the building occupants. Spills occurring outside storerooms and laboratories may lead to hazardous concentrations of vapors and gases being distributed throughout the building.

The following guidelines should be observed when transporting chemicals outside the laboratory:

1. Elevators
   1. Freight elevators shall be used where available to transport hazardous materials. Under no circumstances are passenger elevators to be used for the transportation of hazardous materials if freight elevators are available.
2. Flammable Liquids
   1. Flammable liquids shall be transported in rugged pressure-resistant safety cans.
   2. Original containers of flammable liquids shall be placed in an outside container or acid-carrying bucket.
   3. No more than 5 gallons of flammable liquids in glass containers shall be transported on the freight elevator unless the original shipping carton (box) is used and the materials are on an appropriate cart.
3. Corrosives or Oxidizing Materials
   1. Original glass shipping containers holding liquid acids and bases must be placed in an outside container or acid-carrying bucket.
   2. Incompatible chemicals, for example chromic acid (oxidizing acid) and ethyl acetate (flammable liquid), should not be transported on the same cart unless they are in original shipping cartons and physically separated.
4. Water Reactive Chemicals
   1. Wherever possible, use the original outside shipping containers (packaging) when transporting water reactive chemicals.
   2. Once opened, water reactive chemicals must be placed in a rigid outside container or acid carrying bucket for transporting.
5. Pyrophoric (spontaneously igniting) Substances
   1. Whenever possible, the original outside shipping container (packaging) must be used to transport pyrophoric substances.
   2. Once opened, pyrophoric substances must be placed in a rigid outside container or acid carrying bucket for transporting.
6. Acutely Toxic Compounds (See list Appendix B)
   1. Whenever possible, the original outside shipping container (packaging) must be used to transport acutely toxic compounds.
   2. Once opened, acutely toxic compounds must be placed in a rigid outside container or acid carrying bucket for transporting.
7. General
   1. Chemicals, substances and research materials must be clearly labeled with the correct chemical name when transported. Hand-written labels are acceptable; chemical formulas and structural formulas are not acceptable (except for small quantities of compounds synthesized in the laboratory).
   2. Carts used for chemical transport must have sides, on each shelf, that are high enough to retain the containers. Cart wheels must be large enough to prevent the carts from being caught in floor cracks, and door and elevator thresholds.
   3. Personnel transporting chemicals must wear disposable gloves and safety glasses.