A chemical inventory is a detailed list of all chemicals present in a workplace or laboratory. This inventory includes information such as the name of the chemical, its quantity, location, hazards, and storage requirements. So, maintaining proper inventory and ensuring a seamless ordering process is crucial for lab users to access the right chemicals promptly, use them before expiry, and stay compliant with regulations. An annual hazardous materials inventory is mandatory under Health and Safety Regulation. This inventory should list all hazardous substances present at the workplace, including covered controlled products, explosives, pesticides, radioactive materials, hazardous wastes, and consumer products that could endanger workers in emergencies. Keeping an accurate chemical inventory is essential for ensuring safety, compliance with regulations, and efficient management of chemical supplies. It helps in identifying potential hazards, tracking usage, and preventing accidents or incidents related to chemical handling.
INVENTORY PROCEDURES
The basic categories of information required in a chemical inventory are as follows:
1. Department
The inventory title should indicate the department to which the lab belongs and the head of department and the responsible technician name. This is crucial for identifying the owner of the chemical inventory.
2. Chemical Name and Supplier
Include a column for the chemical name (as labeled on the supplier packaging) and another for supplier details (to facilitate locating the chemical). Optionally, include the Chemical Abstracts Service (CAS) number, especially useful for chemicals with multiple common names (e.g., 2-propanol, isopropanol, isopropyl alcohol). Some inventories may list the product number for easier reordering.
3. Location (Building and Room Number)
Always specify the chemical's location, especially crucial in labs with multiple storage rooms. At a minimum, indicate the building and room number, but additional specifics like 'acid cabinet' can be included.
4. Approximate Quantity
Record the approximate quantity (in kg or L) on the inventory, not the container size unless full. Estimate the quantity if the container is not full.
5. Date Opened and Received
It is best practice to note the date the chemical was received and opened on the bottle directly. This information should also be included in the inventory.
6. WHMIS Class (Hazard Identification)
Include a line in the inventory for the WHMIS class or TDG class. This aids in proper storage, segregation, and understanding the associated risks.
7. Location of Safety Data Sheet (SDS)
The SDS location must be specified in the inventory for emergency situations where the SDS is needed to assess the scenario.
8. SAFETY DATA SHEETS (SDS)
SDSs should be easily accessible to those using hazardous materials and read prior to use. They need updating every 3 years (preferably annually). SDSs can be in hard copy or on a functional computer system accessible to all handlers, even during power outages.
9. Other Necessary Information
In addition to the required details, the chemical inventory should contain any other related information for the lab. For instance, some inventories may list container size alongside the approximate quantity to assist in locating the chemical bottle.
CHEMICAL STORAGE
GENERAL
Hazardous chemicals should be stored under the correct conditions and segregated from other incompatible chemicals as a proactive measure to minimize the formation of unstable or toxic products. In general:
• Store in a central, properly ventilated area that includes forced ventilation from floor to ceiling and with exhaust above roof level.
• Know the location of the master control shut-off valves for gas, water, and electricity.
• Smoke detectors are required.
• A communication system to the main office or emergency system is recommended (these are the landline phones in each lab).
• Shelving should be accessible with chemicals at eye level or lower; no high shelf chemical storage.
• Avoid floor chemical storage (even temporarily).
• Shelf assemblies should be firmly secured to walls. Avoid island shelf assemblies.
• Provide anti-roll lips on all shelves.
• Shelving assemblies must be constructed of wood except for storing oxidizers.
• Avoid metal, adjustable shelf supports and clips; use fixed, wooden supports.
• For emergencies, have:
o Fire extinguishers of the approved type positioned near an escape route, ABC fire extinguishers can be found in hallways close to labs. Specific fire extinguishers (such as Class D) should be kept in the lab close to the hazard.
o Spill control and clean-up materials
o Approved eye/face wash and shower
STOREROOMS
Laboratories are not storerooms, particularly when it comes to chemicals and solvents. Chemicals in laboratories should be stored in areas away from experimental activities and limited to the requirements of 12 months or less. Excess stock should be kept in a proper chemical storage facility. The following basic rules apply particularly to chemicals stored in laboratories.
1. Small Amounts (Order only what you can use in 12 months):
Ordering 1 kg because it is cheaper than the 100 g size is often a false economy. The result:
• It takes up more valuable space
• It presents a greater potential hazard
• It may eventually become a disposal problem.
2. Secure:
i. Avoid overcrowding shelves.
ii. Ensure items are not stored too high; provide a suitable ladder if needed.
iii. Keep solvents in a designated flammable cabinet with the door closed.
iv. Use proper containers for solvents and waste.
v. Store highly toxic or controlled materials in a secure cupboard.
3. Labeling:
i. Clearly label all contents.
ii. Ensure labels are intact and legible.
iii. Avoid overwriting labels; remove old labels or cover them completely.
iv. Label solvent stills.
v. Regularly test and label peroxidizable materials with updated results.
4. Sealed
i. Keep solvent containers closed
ii. Ensure chemical containers are intact
iii. Regularly vent materials capable of building up pressure (e.g. formic acid)
5. Segregated Waste: should be sorted based on WHMIS hazard class and Fire Code Separation of Dangerous Goods for Storage.
SPECIFIC STORAGE REQUIREMENTS
Chemical storage, whether in a lab or central storeroom, must be supervised by a qualified person; storerooms need adequate security.
Acids and Bases:
- Keep acids and bases separate.
- Store acids in a dedicated cabinet.
- Keep oxidizing acids (e.g., nitric acid) away from organic acids (e.g., acetic acid).
- Store organic acids separately from inorganic acids (use different areas or secondary containment).
- Keep organic bases separate from inorganic bases (use different areas or secondary containment).
- Store hydrofluoric and perchloric acids in compatible secondary containers.
- Ensure safety showers and eye wash facilities are easily accessible.
- Regularly inspect protective equipment to ensure proper function, especially in corrosive environments.
Flammable Materials: Flammable liquids should be stored in a dry, cool, well-ventilated area, preferably in a flammable materials storage cabinet or room.
Laboratory Storage:
Flammables should be stored according to the Fire Code and best practices:
- In approved metal safety cans with self-closing lids.
- In original glass bottles up to 5 liters.
- In glass containers (or other compatible material) up to 1 liter when decanted.
- In 4 - 10 L waste solvent containers with venting caps when not in use. Waste should never be placed in metal containers.
CHEMICAL SEGREGATION
When it comes to chemical storage practices, the alphabet should be one of the last criteria used. Examples of compatibility problems arising from storing chemicals alphabetically include:
• Alkanes and Ammonium Nitrate
• Hydrogen Peroxide and Hydrazine
• Ammonia and Bromine
• Nitric Acid and Phenol
• Aldehydes and Amines
• Sodium Cyanide and Sulfuric Acid
• Calcium Hypochlorite and Carbon Even apparently safe storage can be a potential problem. The following are often stored together even though there are hazards if the materials mix:
o Acetic Acid and Nitric Acid
o Perchloric Acid and Sulfuric Acid
o Concentrated Acids and Base
For specific code related information, you may
refer to OSHA's Hazard Communication Standard (29 CFR 1910.1200) or other
relevant regulations pertaining to chemical safety in clinical
laboratories: https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1200
