Self-Contained Breathing Apparatus (SCBA) are one of the most important items of personal protective equipment used by firefighters and rescue personnel. SCBA allow firefighters to enter hazardous environments to perform essential interior operations including offensive fire attack, victim search, rescue and removal, ventilation, and overhaul. They are also used at non-fire incidents involving hazardous materials and confined spaces where there is a threat of toxic fumes or an oxygen-deficient atmosphere. There have been several well-documented incidents during the past 10 years where SCBA failure may have been a contributing factor in the deaths or injuries of firefighters1. These incidents, coupled with a recognition of the importance of selfcontained breathing apparatus to firefighter safety, prompted the United States Fire Administration to undertake this study to address any operational trends associated with SCBA failure incidents, and to identify potential problems requiring correction or further study.