In a new letter to respirator manufacturers and interested parties, NIOSH addresses stakeholder concerns related to DOT-SP-16320, a special permit issued by the U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration to allow the requalification of self-contained breathing apparatus beyond the original 15-year service life. The permit, which was issued to Digital Wave Corporation on Oct. 5, 2017, authorizes the extension of the original equipment manufacturer 15-year service life for certain carbon-fiber reinforced aluminum-lined cylinders in five-year increments, up to 15 additional years, for devices that pass modal acoustic emissions requalification testing. According to NIOSH, the cylinders covered by the permit include those used by fire departments and first responders as a component of a NIOSH-approved SCBA. Stakeholders have approached the agency with concerns that allowing the requalification of SCBA beyond the original 15-year service life may result in health and safety issues for users. NIOSH plans to issue a request for information in the about safety problems documented by manufacturers or users. The agency urges respiratory protection program administrators and SCBA users with questions or concerns about the application of the special permit to review the user instructions, supplemental inserts, safety precautions, and SCBA warranty information provided by the NIOSH approval holder. NIOSH also encourages approval holders to provide respiratory protection program administrators and SCBA users with current recommendations regarding DOT-SP-16320 and service-life limitations.