As the number of biological labs increases, so do the safety risks for lab workers. Data on these risks -- collected through a safety reporting system (SRS) from reports of hazards, incidents, and accidents -- can support safety efforts. However, no such system exists for all biological labs, and a limited system, managed by the Centers for Disease Control and Prevention (CDC) and the Animal and Plant Health Inspection Service (APHIS), applies to only a subset of these labs. Given the increase in biological labs and therefore risks, it is essential to understand the sources of risk and how to communicate them. This book examines the collection of data on accidents, incidents, and hazards in biological labs, that can help identify accident precursors. If the precursors can be identified, communicated, and eliminated, the occurrence of accidents, in particular those resulting in injury or death, might be prevented.