Examining principles and legal considerations, it advises how to isolate plant and equipment safely and how to reduce the risk of releasing hazardous substances during intrusive activities like maintenance and sampling. Includes a methodology for selecting 'baseline' standards and outlines preventive and risk reduction measures. In scoping the pertinent issues, it considers broad matters (eg work control systems or documentation) and specifics like draining or venting. With many detailed diagrams and easy-glance reference tables.