2.D.1 Chemical Procurement
According to the nonmandatory OSHA Laboratory Standard (Appendix A, section D.2(a), Chemical Procurement, Distribution, and Storage), “Before a substance is received, information on proper handling, storage, and disposal should be known to those who will be involved.” The standard further states that “No container should be accepted without an adequate identifying label. Preferably, all substances should be received in a central location.” These procedures are strongly recommended. Personnel should be trained to identify signs of breakage (e.g., rattling) and leakage (e.g., wet spot or stain) on shipments and such shipments should be refused or opened in a hood by laboratory staff.
Some organizations have specific purchasing policies to prohibit unauthorized purchases of chemicals and other hazardous materials. The purchaser must assume responsibility for ownership of the chemical. Because of the possibility of a chemical leak or release and subsequent exposure, chemical shipments should only be received by trained personnel in a laboratory or central receiving area with proper ventilation. Neither administrative offices nor the mail room is appropriate for receipt or opening of chemical shipments.
When preparing to order a chemical for an experiment, several questions should be asked:
• What is the minimum amount of this chemical that is needed to perform the experiment? Is it available elsewhere in the facility? Remember, when ordering chemicals, less is always best. Prudent purchasing methods will save storage space, money, and disposal costs. Larger containers require more storage space and will incur additional disposal costs if the chemical is not used.
• Has the purchase been reviewed by the CHO to ensure that any special requirements can be met?
• Is the proper PPE available in the laboratory to handle this chemical?
• What are the special handling precautions?
• Where will the chemical be stored in the laboratory?
• Does the laboratory chemical hood provide proper ventilation?
• Are there special containment considerations in the event of a spill, fire, or flood?
• Will there be additional costs or considerations related to the disposal of this chemical?
2.D.2 Chemical Storage
To lessen risk of exposure to hazardous chemicals, trained laboratory personnel should separate and store all chemicals according to hazard category and compatibility. In the event of an accident involving a broken container or a chemical spill, incompatible chemicals that are stored in close proximity can mix to produce fires, hazardous fumes, and explosions. Laboratory personnel should read the MSDS and heed the precautions regarding the storage requirements of the chemicals in the laboratory. A detailed chemical compatibility table is included in Chapter 5, section 5.E.2, Table 5.1.
To avoid accidents, all chemical containers must be properly labeled with the full chemical name, not abbreviations, and using a permanent marker. All transfer vessels should have the following label information:
• chemical name,
• hazard warnings,
• name of manufacturer,
• name of researcher in charge, and
• date of transfer to the vessel.
Incoming chemical shipments should be dated promptly upon receipt, and chemical stock should be rotated to ensure use of older chemicals. It is good practice to date peroxide formers upon receipt and date again when the container is opened so that the user can dispose of the material according to the recommendations on the MSDS. Peroxide formers should be stored away from heat and light in sealed airtight containers with tight-fitting, nonmetal lids. Test regularly for peroxides and discard the material prior to the expiration date. (For more information about storage and handling of peroxides, see Chapter 4, section 4.D.3.2, and Chapter 6, section 6.G.3.)
When storing chemicals on open shelves, always use sturdy shelves that are secured to the wall and contain ¾-in. lips. Do not store liquid chemicals higher than 5 ft on open shelves. Do not store chemicals within 18 in. of sprinkler heads in the laboratory. Use secondary containment devices (i.e., chemical-resistant trays) where appropriate. Do not store chemicals in the laboratory chemical hood, on the floor, in the aisles, in hallways, in areas of egress, or on the benchtop. Chemicals should be stored away from heat and direct sunlight.
Only laboratory-grade explosion-proof refrigerators and freezers should be used to store properly sealed and labeled chemicals that require cool storage in the laboratory. Periodically clean and defrost the refrigerator and freezer to ensure maximum efficiency. Domestic refrigerators and freezers should not be used to store chemicals; they possess ignition sources and can cause dangerous and costly laboratory fires and explosions. Do not store food or beverages in the laboratory refrigerator. (For more information, see Chapter 7, section 7.C.3.)