Chemicals should be listed in the school’s chemical inventory, and the storage should be well organized.
General Considerations
Hazardous chemical substances must be stored so that they are not accessible to unauthorized people. The chemistry facilities in a school should therefore always be locked or supervised, and a qualified person should be appointed to ensure that the chemicals are stored appropriately.
The chemical cabinets and rooms where chemicals are stored should be locked. If the science department has a main gas supply, the gas should be switched off at the main tap when not in use.
Large amounts of hazardous chemicals pose a safety risk. Try to estimate the yearly consumption of each chemical, and only store the amount which is actually needed. Substances that are not in regular use should be removed and disposed of appropriately.
The appointed person should check stored chemicals in accordance with the schools’ routine for safe storage of chemicals.
How to Organize Storage?
A chemistry department normally needs five–six separate cabinets for storage of chemicals and gases. Labelled waste disposal containers should be stored in appropriate cabinets.
Chemical Inventory
Schools are required to maintain an updated chemical inventory. All hazardous chemicals that are kept in the school should be in this inventory, including information regarding where – in which room, cabinet and shelf – they can be found. A chemical inventory could consist of the safety data sheets for all chemicals and solutions the science department has bought and a spreadsheet that lists all of these. Depending on national laws the chemical inventory can be physical or digital.
Cabinets
Cabinets could be made of either metal or wood depending on the properties of the stored chemicals. Ventilated cabinets should have mechanical ventilation. Separate outlets are required so that air does not pass through one cabinet and then another before exiting through the common outlet duct.
The ventilated cabinets should be checked regularly, for example every five years. It is also important to check that the hinges on the cabinets have not become damaged or rusty, for example due to contact with acids.
How to Start Organising Your Chemicals
Start with considering the needs for storage, by looking at the list below.
- Separate solids from liquids.
- Solid non-hazardous substances do not need to be stored in a special cabinet.
- Store liquid chemicals below eye level. It is better to buy and store liquids in several smaller bottles than one large heavy one. The largest containers should be stored on the bottom shelves.
- Do not stockpile chemicals. Check the chemicals for use-by dates.
- Keep bottles containing liquids in an upward position, preferably in polypropylene (PP) or polyethylene (PE) retention trays as extra protection.
Suggestion for Storage
Hazardous chemicals with special storage requirements, for example oxidising agents, flammable substances/gases, and CMR/toxic chemicals, need to be kept in separate cabinets when stored. Check the labelling of the chemical, or the safety data sheet (section 2 – Hazard Identification, section 7 – Handling and Storage, and section 10 – Stability and Reactivity), to determine which kind of storage is appropriate.
| Cabinet | Storage requirement(s) | Hazard pictogram |
|---|---|---|
Cabinet 1:
| Separated from flammable substances. Metal cabinet. |  |
Cabinet 2:
| Ventilated metal cabinet. Notes: Flammable chemicals can catch fire spontaneously. Water reactive substances can react violently in contact with water. |  |
Cabinet 3:
| Ventilated cabinet. Store containers below eye level. Advice: Concentrated acids should be stored in secondary containers. |  |
Cabinet 4:
| Ventilated cabinet. Store containers below eye level. Advice: Concentrated bases should be stored in secondary containers. | |
Cabinet 5:
| Cabinet, ventilated if containing volatile substances. |    |
Cabinet 6:
| Ventilated, fire-proof cabinet. Do not store near flammable chemicals. The cabinet has to be marked with a yellow “gas under pressure” sign. |  |
If a chemical has multiple hazard pictograms, it should be stored in the highest priority category storage. Oxidizing agents have the highest priority followed by flammable substances. This is the order of priority:
- Oxidizing
- Flammable
- Corrosive
- Serious health hazard / Acute toxicity
- Health hazard / Hazardous to the environment
Possibilities for Co-Storage
The number of cabinets or space is often limited. It is possible to co-store chemicals from different hazard classes. The table below can be used to determine whether chemicals in different hazard classes can be stored together. Cells coloured red means that chemicals should not be co-stored. Yellow cells indicate that you have to consult the safety data sheet for more information about the possibility of co-storage.
| Oxidizing | Flammable | Corrosive: ACID | Corrosive: BASE | health hazard / toxic | |
|---|---|---|---|---|---|
Oxidizing | Compatible | Not compatible | Store according to SDS Section 7 and 10 | Store according to SDS Section 7 and 10 | Store according to SDS Section 7 and 10 |
Flammable | Not compatible | Compatible | Not compatible | Not compatible | Store according to SDS Section 7 and 10 |
Corrosive: Acid | Store according to SDS Section 7 and 10 | Not compatible | Compatible | Not compatible | Not compatible |
Corrosive: Base | Store according to SDS Section 7 and 10 | Not compatible | Not compatible | Compatible | Store according to SDS Section 7 and 10 |
health hazard / toxic | Store according to SDS Section 7 and 10 | Store according to SDS Section 7 and 10 | Not compatible | Store according to SDS Section 7 and 10 | Compatible |
Toxic Substances
Very toxic substances should not be stored in the same cabinet as substances that can cause a fire or explosions. In the event of an explosion, greater damage can be caused by spreading the toxic substance than by the explosion itself.
Group 1 and 2 Metals
Group 1 and 2 metals are very reactive in contact with water and acidic solutions. The reaction produces flammable hydrogen gas. These metals should be stored separately from all aqueous solutions and oxidizers. For example, magnesium powder should be stored separately from potassium iodate and potassium permanganate.
Household Chemicals and Foods
Substances intended for consumption must not be stored in the same storage space as hazardous chemicals. Experiments with taste tests should be carried out in a regular classroom and not in the science classroom or laboratory.
Gases and Aerosols
Cabinets for gas burners must be marked with a warning sign stating “Gas under pressure”. This also applies to the room in which the cabinet is located. The local fire service, or similar, may require further marking showing where the gas containers are stored, so that they can easily be found and isolated in the event of a fire. Local regulation may require more documentation if larger volumes are in use.
All gas containers must be stored in a secured upright position. Carbon dioxide (CO₂), must be stored in a ventilated room to avoid suffocation in case of a leakage.
Light Sensitive Chemicals
Light sensitive chemicals should be stored in dark vessels, according to the chemical’s safety data sheet.