As discussed above, although MSDSs are invaluable resources, they suffer some limitations as applied to risk assessment in the specific context of the laboratory. Appendix B introduces the concept of the Laboratory Chemical Safety Summary (LCSS), which is specifically tailored to the needs of the laboratory worker. As indicated in their name, LCSSs provide information on chemicals in the context of laboratory use. These documents are summaries and are not intended to be comprehensive or to fulfill the needs of all conceivable users of a chemical. In conjunction with the guidelines described in this chapter, the LCSS provides essential information required to assess the risks associated with the use of a particular chemical in the laboratory.
The format, organization, and contents of LCSSs are discussed in detail in the introduction to Appendix B. Included in an LCSS are the key physical, chemical, and toxicological data necessary to evaluate the relative degree of hazard posed by a substance. LCSSs also include a concise critical discussion, presented in a style readily understandable to laboratory workers, of the toxicity, flammability, reactivity, and explosibility of the chemical; recommendations for the handling, storage, and disposal of the title substance; and first aid and emergency response procedures.
Appendix B contains LCSSs for 88 chemical substances. Several criteria were used in selecting these chemicals, the most important consideration being whether the substance is commonly used in laboratories. Preference was also given to materials that pose relatively serious hazards. Finally, an effort was also made to select chemicals representing a variety of different classes of substances, so as to provide models for the future development of additional LCSSs.
Commercial suppliers are required by law to provide their chemicals in containers affixed with precautionary labels. Labels usually present concise and nontechnical summaries of the principal hazards associated with their contents. Note that precautionary labels should not replace MSDSs and LCSSs as the primary source of information for risk assessment in the laboratory. However, labels can serve as valuable reminders of the key hazards associated with the substance.
The resources described above provide the foundation for risk assessment of chemicals in the laboratory. This section highlights the sources that should be consulted for additional information on specific harmful effects of chemical substances. Although MSDSs and LCSSs include considerable information on toxic effects, in some situations the laboratory worker should seek additional, more detailed information. This step is particularly important when the worker is planning to use chemicals that have a high degree of acute or chronic toxicity or when it is anticipated that work will be conducted with a particular toxic substance frequently or over an extended period of time. Section 3.B of this chapter provides explicit guidelines as to how laboratory workers can use the information in an MSDS or LCSS to recognize when it is necessary to seek such additional information.
The following annotated list provides references on the hazardous properties of chemicals in the approximate order of their utility in assessing risks in the laboratory. The first six references are particularly valuable sources of information, and it is strongly recommended that copies of these be made readily accessible to laboratory workers at all times. A compilation of related materials and recommended resources can be found in the bibliography.
Occupational Health Guidelines for Chemical Hazards, U.S. DHHS; F. W. Mackison, R. S. Stricoff, and L. J. Partridge, editors, DHHS (NIOSH) Publication Number 81-123, U.S. Government Printing Office, Washington, D.C., 1981, and a supplement published as DHHS (NIOSH) Publication No. 89-104, U.S. Government Printing Office, Washington, D.C., 1988. The guidelines currently cover almost 400 substances and are based on the information assembled under the Standards Completion Program, which served as the basis for the promulgation of federal occupational health regulations ("substance-specific standards"). Typically five pages in length and written clearly at a level that should be readily understood by laboratory workers, each set of guidelines includes information on physical, chemical, and toxicological properties, signs and symptoms of exposure, and considerable detail on control measures, medical surveillance practices, and emergency first aid procedures. However, some guidelines date back to 1978 and may not be current, particularly with regard to chronic toxic effects.
Chemical Safety Data Sheets, Royal Society of Chemistry, five volumes, Cambridge, United Kingdom, 1989-1992. This excellent collection of data sheets summarizes hazard information on more than 500 chemicals. These are more useful for the laboratory worker than most MSDSs and are similar in aim to the LCSSs. Sections include threshold limit values, physical properties, chemical hazards, biological hazards (e.g., vapor inhalation, eye contact, skin contact, swallowing), carcinogenicity, mutagenicity, reproductive hazards, first