cient purity to be used "as is" in many procedures. If the purity is in doubt, the worker who returned the material should be consulted. The stockroom personnel can update the central inventory periodically to indicate which containers of which materials are available for this exchange or transfer. For an exchange program to be effective, all contributors to and users of the facility must reach a consensus on the standards to be followed concerning the labeling and purity of stored chemicals.
A word of caution needs to be offered in regard to surplus-chemical stockrooms. It is essential that such a facility be managed with the same degree of control that is afforded a new-chemical storage area. The surplus-chemical stockroom must not be operated as a depository for any chemical that probably will not be wanted in the laboratory within a reasonable period (e.g., 2 to 3 years); such materials should be disposed of properly. Rooms that are used as general depositories of unwanted chemicals are likely to become "mini-Superfund" sites because of lack of control. Academic institutions should consider recycling common organic solvents from one research laboratory to another, or from research laboratories to teaching laboratories. For example, chromatography effluents such as toluene could be collected from research laboratories, distilled, and checked for purity before reuse.
Such laboratory-to-laboratory exchange can be an effective alternative to a central surplus-chemical stockroom in organizations unwilling or unable to manage a central storeroom properly. In such a system, workers in the individual laboratory retain responsibility for the storage of unwanted chemicals but notify colleagues periodically of available materials. A chemical tracking system as described above can facilitate an exchange system greatly. If colleagues within the same laboratory are using the same hazardous material, particularly one that is susceptible to decomposition upon contact with air or water, they should try to coordinate the timing of their experiments.
Commercially packaged chemical containers received from 1986 onward generally meet current labeling requirements. The label usually includes the name of the chemical and any necessary handling and hazard information. Inadequate labels on older containers should be updated to meet current standards. To avoid ambiguity about chemical names, many labels carry the CAS registry number as an unambiguous identifier. This information should be added to any label that does not include it. On receipt of a chemical, the manufacturer's label should be supplemented by the date received and possibly the name and location of the individual responsible for purchasing the chemical. If chemicals from commercial sources are repackaged into secondary containers, the new containers should be labeled with all essential information on the original container. Warning: Do not remove or deface any existing labels on incoming containers of chemicals and other materials.
The contents of all chemical containers, including, but not limited to, beakers, flasks, reaction vessels, and process equipment, should be properly identified. The overriding goal of prudent practice in the identification of laboratory chemicals is to avoid orphaned containers of unknown materials that may be expensive or dangerous to dispose of. The labels should be understandable to laboratory workers, members of well-trained emergency response teams, and others. Labels or tags should be resistant to fading from aging, chemical exposure, temperature, humidity, and sunlight. Chemical identification and hazard warning labels on containers used for storing chemicals should include the following information:
name, address, and telephone number of the chemical manufacturer, importer, or responsible party (including researcher),
chemical identification and identity of hazard component(s), and
appropriate hazard warnings.
Containers in immediate use, such as beakers and flasks, should, at a minimum, be labeled with the name of the chemical contents. Labeled materials transferred from primary (labeled) containers to secondary containers (e.g., safety cans and squeeze bottles) should include chemical identification and synonyms, precautions, and first aid information.
Labeling of all containers of experimental chemical materials is prudent. Because the properties of an experimental material are generally not completely known, its label cannot be expected to provide all necessary information to ensure safe handling.
The most important information on the label of an experimental material is the name of the researcher responsible, as well as any other information, such as a laboratory notebook reference, that can readily lead to what is known about the material. For items that are to be stored and retained within a laboratory where the properties of materials are likely to be well understood, only the sample identification and/or name may