In 1984, the Council of State Science Supervisors, in association with the U.S. Consumer Product Safety Commission and the National Institute for Occupational Safety and Health, published the safety guide School Science Laboratories: A Guide to Some Hazardous Substances to help science teachers identify hazardous substances that may be used in school laboratories and provide an inventory of these substances. Because school science curricula have changed since then, the safety guide has been updated and revised to reflect those changes. This guide on safety in the chemistry laboratory was also written to provide high school chemistry teachers with an easy-to-read reference to create a safe learning environment in the laboratory for their students. The document attempts to provide teachers, and ultimately their students, with information so that they can take the appropriate precautionary actions in order to prevent or minimize hazards, harmful exposures, and injuries in the laboratory.