Chemical Storage

*NEW* The SFU Hazardous Chemical Storage Manual is now available.

Proper chemical storage is a complex and challenging component of laboratory management. Poor or incorrect chemical storage practices can result in inadvertent reactions between incompatible materials with potential to cause chemical exposure, injury, fire or explosion.

SFU’s Hazardous Chemical Storage Manual is intended to promote the safe storage of chemicals by offering information on regulatory compliance and best practices for chemical labelling and general storage requirements, as well as specific storage and segregation information for certain types of chemicals. This Manual applies to all faculty, staff, students and visitors at the University who will be involved in the use and management of chemical storage in laboratories.

General storage requirements

See below for some basic storage requirements and refer to the manual for additional details:

  • Chemicals must be stored according to chemical compatibility such that incompatible materials do not come in contact with each other in the event of a breakage or spill.
  • In cases where it is not practical to store incompatible chemicals in physically separate locations, it is acceptable to segregate chemicals using glass, porcelain or heavy gauge plastic secondary containers. The secondary containers must be compatible with the material being stored and large enough to contain any spills.
  • Ensure storage areas have adequate lighting and ventilation, and are maintained at a consistent, cool temperature.
  • Ensure chemical storage areas do not block aisles, hallways, doorways, exits or emergency equipment (e.g., eyewash, shower, pull stations, fire extinguisher).
  • Do not store chemicals in a fume hood unless the fume hood is used exclusively for storage and is labelled as such.

Storage Equipment

Using specially designed equipment for storage of flammables, acids, or corrosives allows certain specific requirements to be met. Equipment should be labelled with the hazard class(es) of the chemicals stored within.

  • Flammable storage cabinets are not required to be vented and it is not recommended. Ensure safety caps (bungs) are in place over ventilation ports so as to contain/protect contents from fire.
  • Acid and corrosive storage cabinets must be completely lined with corrosion-resistant materials and include corrosion-resistant hardware. It is recommended that they be located below the fume hood and vented in order to prevent the buildup of corrosive vapours, which can degrade the inside of the cabinet.
  • Fume hoods should not be used for long-term chemical storage. Fume hoods which have been designated for temporary chemical storage must be labelled “For Storage Only”.
  • Ordinary (domestic) refrigerators and freezers used for chemical storage must never be used to store food (and labelled "NO FOOD - LAB CHEMICAL STORAGE ONLY") and must not be used for storage of flammable liquids.

Specific storage requirements

Storage requirements for the most common chemical hazard classes are summarized below. Refer to the manual for additional details related to these and other hazard classes.

Note that many chemicals fall into multiple hazard classes. Consequently, it may be necessary to consult several sections to determine how to store a chemical safely. Furthermore, some complex substances may not fit easily into any category, in which case it becomes necessary to consult various other resources (e.g., Safety Data Sheet or SDS, literature, your Supervisor, EHRS) in order to determine safe storage conditions.

Flammable and combustible liquids

  • Examples include: acetone, diethyl ether, ethanol, hexane, methanol, tetrahydrofuran, toluene, and xylene.
  • Store a maximum of 25 L of flammable and combustible liquids in the open laboratory. Larger volumes must be stored in an approved flammable storage cabinet, up to a maximum of 500 L per fire compartment (i.e., a laboratory or a shared laboratory).
  • Keep flammable and combustible materials away from any ignition sources: heat, flames, sparks, hot surfaces and direct sunlight.
  • Keep flammable and combustible materials away from strong oxidizing agents, such as nitric or chromic acid, permanganates, chlorates, perchlorates and peroxides.
  • Containers of flammable and combustible liquids must not exceed a capacity of 5 L.
  • Ensure an appropriate fire extinguisher is readily available in the laboratory and that laboratory occupants are trained to use it.
  • Flammable cabinets are used preferentially for flammable liquids and if space allows, for combustible liquids.
  • Refrigerators and freezers used for storing flammable or combustible liquids must be “Lab safe” or rated for flammable material storage.

Corrosives

  • Examples include: organic acids such as acetic and citric acids; inorganic acids such as hydrochloric, hydrofluoric, nitric, and sulfuric acids; organic bases such as diethylamine and piperidine; and inorganic bases such as potassium hydroxide and sodium hydroxide.
  • If storage space permits, acids and bases should be stored in separate cabinets, but can be stored together when segregation is ensured with secondary containment bins.
  • Segregate inorganic acids from organic acids and inorganic bases from organic bases, as a general rule of thumb.
  • Nitric acid is a strong oxidizer and it must be isolated from other acids and stored separately from incompatibles: flammables, bases, hydrogen sulfide, organic materials, metals and metal compounds.
  • Hydrofluoric acid attacks glass and should be stored in tightly closed polyethylene, Teflon, neoprene or nitrile containers. For long-term storage, check permeation ratings for chosen container material. For more information, refer to the link for Hydrofluoric acid in Substance specific procedures.
  • Do not store corrosives on metal shelves.
  • Use corrosion resistant bins (e.g., polypropylene) as secondary containment for spills, leaks, drips or weeping.
  • Cabinets used for corrosives storage should be made of corrosion resistant materials and vented.  

Toxics

  • Examples include: acrylamide, ammonia, aniline, 2-mercaptoethanol, mercury, phenol, and sodium cyanide.
  • Non-volatile toxic chemicals may be stored in a normal cabinet, separate from incompatibles.
  • Volatile toxic chemicals should be stored in a ventilated cabinet.
  • Ensure containers are tightly sealed to minimize exposure to personnel and contamination of other chemicals.
  • Toxic chemicals that are acid sensitive, such as cyanides and sulfides, must be stored in a separate location from acids and protected from contact.
  • Severe poisons should be stored in a dedicated cabinet.
  • Controlled substances have additional precautions for secure storage. Contact EHRS for assistance.

Oxidizers

  • Examples include: ammonium persulfate, nitric acid, potassium permanganate, chlorates, perchlorates, and peroxides.
  • Store in a cool, dry place. Some may require refrigeration – consult the SDS.
  • Segregate from flammable and combustible materials, including paper and cardboard.
  • Store separately from reducing agents (e.g., zinc, alkaline metals, formic acid).

Compressed gases

  • Limit the quantity of compressed gas cylinders in a laboratory to what is needed for normal operation (i.e., on a weekly basis), since regular delivery can be arranged. Note the gas cylinder supplier delivers twice a week to the Burnaby campus. Any cylinders not required for normal operation must be placed in designated cylinder storage areas.
  • Store compressed gas cylinders in a cool, dry area, and away from incompatible materials, sparks, flames, or excessive heat.
  • Protect cylinders from sources of potential physical damage, electrical contact or corrosion (e.g., moisture, salt, acids or chemical fumes).
  • Segregate gas cylinders according to gas type.
  • Identify empty gas cylinders with an “EMPTY” tag and keep separate from full cylinders.
  • Secure cylinders in an upright position, attached to a wall or within a cylinder storage rack. Each cylinder must be restrained by 2 chains: one placed at one third from the top of the cylinder and the other placed at one third from the bottom. Polypropylene and other synthetic plastic straps are not recommended for securing cylinders as they will melt in a fire.
  • Bench clamps are not recommended as they are not seismically secure.
  • Keep valve protection cap in place (for cylinders designed to accept a cap) when cylinder is not in use and anytime the cylinder is being moved.
  • Do not leave a regulator on an unused cylinder for an extended period of time.
  • Never store cylinders in any exit or corridor providing access to exits; under any fire escape, outside exit stairs, passage or ramp; or within 1 m of any exit or electrical panel.
  • Indoor areas where large amounts of inert gas cylinders are stored may need to be continuously monitored for oxygen levels. Contact EHRS for assistance to determine if monitoring is needed in your area.
  • When ordering, choose refillable cylinders whenever possible.

Cryogens and dry ice

  • Examples of cryogens include: liquid helium and liquid nitrogen. Although not a cryogen, solid carbon dioxide or dry ice also presents similar hazards to cryogens.
  • Store cryogens only in approved storage vessels (e.g., Dewars) that are vacuum jacketed and equipped with insulation, pressure-relief valves and rupture devices.
  • Dewar flasks can collapse from thermal or mechanical shock. Ensure Dewar flasks are shielded with fiber tape or enclosed in a metal container to reduce the risk of flying glass in the event the Dewar flask fails.
  • Store all containers with cryogens or dry ice in well-ventilated areas.
  • Liquid nitrogen and liquid helium are capable of liquefying oxygen from the air. This form of oxygen enrichment can become a fire or explosion hazard. Therefore, store all cryogenic liquids away from combustible material and do not leave containers uncovered for long periods of time. Use a loose fitting stopper or lid.
  • Store dry ice in Styrofoam boxes or covered but unsealed insulated containers.
  • Cold rooms are not well ventilated and can quickly become an asphyxiation hazard when cryogens are used in them. Cryogens should not be stored in cold rooms.

Hazardous waste

  • Store hazardous waste only short term, until the next available waste take away date.
  • Ensure all waste is labelled. Standard SFU waste labels can be found at Science Stores or by contacting EHRS.
  • Solvent waste should be segregated into separate halogenated, non-halogenated, and waste oil containers. Use the provided 5 L white/translucent containers and fill only to the “max fill line.”
  • Other solid and liquid chemical waste can be stored in appropriate and properly labelled containers.
  • Collect and store waste according to compatibility and place in secondary containment bins when practical while awaiting pickup.
  • Allow sufficient head space for waste containers storing aqueous waste, and fill to 75% the total container volume and use self-venting caps where appropriate.
  • Chemical waste containers awaiting pickup may be kept in an appropriate location such as a flammable storage cabinet, acid cabinet, or a designated fume hood, depending on the nature of the waste.