In the field of compressed gases and related equipment, there is an expanding core of essential knowledge that people handling and using these materials should be familiar with or should know where to find when necessary. The focus of this book concerns the properties and the accepted means of trans­ portation, storage, and handling of compressed gases. This Handbook is simul­ taneously intended as an overview of the subject and a source of supplementary information. It is also intended to serve as a guide to pertinent federal regulatory requirements and published standards of the Compressed Gas Association and other standards-writing bodies. Readers are advised that the CGA technical pamphlets remain the official state­ ment of policy by the Association on a particular matter. Reference is made throughout this text to the numerous technical pamphlets published by the Com­ pressed Gas Association. Some of these publications have been incorporated by reference into federal, state, provincial, and local regulations. Since these pam­ phlets are reviewed on a periodic basis, wherever the text of this Handbook may be found in conflict with corresponding information in the CGA technical pam­ phlets, the latter shall take precedence.