This training manual is designed to lay the foundation for trainers and technicians by showing the steps to achieve and maintain good indoor air quality through use of cleaner-burning forklifts and materials handlers. The first part of the manual consists of nine units that provide informational material and diagrams on these topics: comparison of gaseous fuels to gasoline; fuel system operation; propane tanks; compressed natural gas (CNG) cylinders; fuel system components; health and safety; fueling; maintenance and repair; and exhaust emissions. A glossary is provided. The second part of the manual contains a suggested agenda for a 2-day course covering the material. A one-page lesson plan called instructor notes is provided for each unit as well as the following: introductions, pretests, definitions, summary and discussion, posttest, feedback and evaluations, and fast-breaking news. Instructor notes follow this format: time for the section, section title, objectives, content sequence, and media materials needed. The third part of the manual contains student activity sheets in this format: places for student name and date; objective; equipment required; safety requirements; procedure; and any necessary material. The final section consists of the pretest and posttest and answer sheets for the two tests. (YLB)