A guide to the safe use of powder actuated fastening tools by operators was developed. The types of tools, fasteners, and powder loads are described. Problems and hazards that could result in serious injury if the tools are not used according to manufacturer's instructions, and federal, state, and local safety codes are reviewed. Safe working practices in tool use are outlined. The authors conclude that safe operation of powder actuated tools requires operator alertness, knowledge, and adherence to safe practices. They suggest that the information contained in this booklet combined with specific tool training and operator certification in tool use will provide the knowledge for safe operation of fastening systems.