Results of "live burn" studies and laboratory tests conducted by National Institute of Standards and Technology (NIST) fire researchers helped to prompt a safety alert warning of heat-caused damage to facepiece lenses on widely used firefighter self-contained breathing apparatus (SCBA), a factor implicated in several first-responder fatalities and injuries.
Faceplate of a fire fighter breathing apparatus damaged by high temperatures in NIST tests Pressure sensor (brass fitting that was mounted on the face of the headform) is visible through the hole in the lens. Credit: NIST View hi-resolution image
Issued by the National Fire Protection Association (NFPA), the alert notes that fires in modern buildings and houses burn hotter and faster than those in older structures, resulting in temperatures high enough to melt or otherwise damage the SCBA facepiece lens. Damage to the lens can breach the respiratory protection, exposing the wearer to superheated air and toxic combustion products. NFPA, a consensus standards organization, is considering relevant tests and other requirements for firefighter personal protective equipment and clothing as part of its code revision process. In the interim, NFPA recommends five steps that fire departments and training academies should take to prevent lens failures. NIST-led research "validated the adverse consequences to firefighters when lens degradation occurs in extreme thermal conditions and developed and provided new testing and performance methodologies to the NFPA Technical Committee on Respiratory Protection Equipment," the safety alert explains. In 2010, NIST, NFPA, the National Institute for Occupational Safety and Health and the Fire Protection Research Foundation hosted a research-planning workshop on evaluating and addressing concerns regarding the thermal performance of SCBA facepiece lenses. Subsequently, NIST conducted research* at live burn tests in the Chicago area and at its own laboratories. It concluded that existing testing methods do not "capture the conditions of temperature, heat flux and duration that a firefighter might experience." The NIST-developed test methods and performance criteria are proposed to be included into the next edition of NFPA 1981, Standard on Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency Services, which NFPA expects to issue later this year. The U.S. Fire Administration and the Science and Technology Directorate of the Department of Homeland Security provided funding for this research to improve the performance of fire fighter protective equipment. * See the Dec. 6, 2011, Tech Beat story, "Study Finds Failure Points in Firefighter Protective Equipment" at www.nist.gov/public_affairs/tech-beat/tb20111206.cfm#scba.
