Proper storage of chemicals in biochemistry labs is essential for maintaining their stability, ensuring safety, and preventing contamination or degradation. Here are the key aspects of the storage of chemicals in a biochemistry lab:
Labelling and Documentation
- Clear Labelling: Every chemical container should be clearly labelled with:
- Chemical name
- Concentration (if applicable)
- Date of preparation or receipt
- Expiry date (if applicable)
- Hazard symbols (e.g., corrosive, flammable)
- Safety Data Sheets (SDS): Ensure that Safety Data Sheets are available for all chemicals and easily accessible.
General Storage Guidelines
- Separation of Incompatibles: Store chemicals that can react dangerously with each other in separate, designated storage areas. For example:
- Acids should be stored away from bases.
- Oxidizers should be stored away from flammable materials.
- Ventilation: Store volatile and hazardous chemicals in well-ventilated areas or fume hoods.
- Sealed Containers: Keep containers tightly closed to avoid contamination, evaporation, or moisture absorption.
Storage Conditions Based on Chemical Type
Room Temperature (20–25°C)
- Dry Chemicals and Powders: Many salts, dry reagents, and stable chemicals can be stored at room temperature in a cool, dry place.
- Stable Solutions: Some buffer solutions and non-volatile reagents are fine at room temperature.
Refrigeration (2–8°C)
- Enzymes: Many enzymes and other proteins require refrigeration to maintain their activity.
- Biological Reagents: Solutions like buffers with sensitive components (e.g., BSA, glucose) should be stored in the fridge.
- Volatile Compounds: Some chemicals (e.g., organic solvents) that degrade at room temperature must be refrigerated.
Freezing (-20°C or -80°C)
- Proteins and DNA/RNA Samples: Store at -20°C to -80°C to prevent degradation.
- Enzyme Stocks: Long-term storage of enzymes is typically done at freezing temperatures.
- Aliquoting: For sensitive reagents, freeze in small aliquots to prevent repeated thawing and freezing.
Dark Storage for Light-sensitive Chemicals
- Light-sensitive Compounds: Certain dyes, vitamins, and biological reagents degrade in light, so they should be stored in amber bottles or in dark, cool places.
Storage for Hazardous Chemicals
Acids and Bases
- Corrosive-resistant Cabinets: Strong acids (e.g., HCl, H₂SO₄) and bases (e.g., NaOH) should be stored in corrosion-resistant cabinets.
- Secondary Containment: Store in trays or containers to prevent spills.
Flammable and Volatile Chemicals
- Flammable Storage Cabinets: Volatile organic solvents (e.g., ethanol, methanol, acetone) should be stored in flame-proof cabinets away from heat sources.
- Ventilation: Ensure proper ventilation to avoid fume buildup.
Toxic Chemicals
- Tightly Sealed: Toxic chemicals should be kept in tightly sealed containers to prevent inhalation or contamination.
- Special Handling: Follow specific safety procedures for highly toxic or carcinogenic chemicals.
Expiration and Inventory Management
- Expiration Date Check: Routinely inspect chemicals for expiration and signs of degradation (e.g., colour change, precipitation).
- First In, First Out (FIFO): Use chemicals in the order they are received to avoid unnecessary waste.
- Inventory System: Maintain an organized inventory with logs of chemicals received, used, and disposed of chemicals.
Disposal of Chemicals
- Proper Disposal of Chemicals Protocols: Follow local regulations and lab-specific guidelines for disposing of expired, degraded, or excess chemicals.
- Special Disposal for Hazardous Waste: Toxic, corrosive, or flammable chemicals often require special disposal methods and should never be discarded down the sink.