During the past two decades, many books, governmental reports and regulations on safety measures against chemicals, fire, microbiological and radioactive hazards in laboratories have been published from various countries. These topics have also been briefly discussed in books on laboratory planning and management. The application of various scientific instruments based on different ionizing and non-ionizing radiations have brought new safety problems to the laboratory workers of today, irrespective of their scientific disciplines, be they in medicine, natural or life sciences. However, no comprehensive laboratory handbook dealing with all these hazards, some of which are recently introduced, has so far been available in a single volume. Therefore, it was thought worthwhile to publish this handbook on safety and health measures for laboratories, with contributions from several experts on these subjects. As this is a multi-author volume, some duplication in content among the chapters is unavoidable in order to maintain the context of a chapter as well as to make each chapter complete. An attempt has also been made to maintain the central theme, which is how to work in a laboratory with maximum possible environmental safety. I am indebted to Mr D. G. T. Bloomer of MTP Press Limited, who has undertaken the publication of this volume and to Mrs M. R. Lingard-Pal, for acting as an honorary editorial assistant. S. B. PAL 1985 vii List of Contributors Numbers in parentheses indicate the page on which the authors' articles begin P. BOWKER B. L.