This is a practical, quick reference guide for those who are actively involved in protecting the health of the worker. It is organized for rapid access, clarity and conciseness. Contents refer to various chemicals, drugs, insecticides and other compounds. The entries are listed by their most familiar names from ABRIN to ZIRCONIUM. Each entry contains all the data that the seeker needs to know-synonyms, all aspects of toxicity. Threshold Limit Values, tests, treatment, and precautions to be observed. The appendix contains an extensive bibliography. Preface - The third edition of this handbook, like the previous work, is intended as a practical, quick reference guide for those who are actively involved in protecting the health of the worker. While the entire text has been updated, an outline form is retained for rapid access, clarity, and conciseness. In a rapidly changing occupational environment some of the material included here may soon be outdated, and other chemicals and compounds not mentioned will generate significant future interest. The TL V s used are those currently recommended by ACGIH, but it should be noted that federal and state agencies as well as foreign governments often issue different standards. Carcinogens continue to command attention and require diligent efforts for protective strategies. In many instances, medical surveillance techniques and preventive measures for work practices are prescribed by law and must be followed as indicated in given jurisdictions. Similarly, the adverse effect on reproductive health from chemical exposures in the workplace has also received much attention, but the precise relation between exposure and specific reproductive problems is apt to remain elusive for some time to come. It can only be resolved by intense epidemiological and experimental research. Current emphasis on research in performance assessment and evaluation in the selection and use of protective equipment is refreshing. Both ANSI and OSHA standards address eye and face protection and the American Conference of Governmental Industrial Hygienists has published "Guidelines for the Selection of Chemical Protective Clothing." Other sources of information on advances in this expanding area include the U.S. Coast Guard, U.S. Fire Administration, NIOSH, and EPA.