Characterization of the Atmosphere within Vapor-Resistant Encapsulating Personal Protective Equipment during Treadmill Exercise

AbstrastBackground. Hazardous materials technicians may be required to wear fully encapsulated vapor-resistant (Level A) personal protective equipment (PPE) to contain and mitigate a hazardous materials emergency. It is commonly taught and practiced in hazardous material technician courses that if the wearer's self-contained breathing apparatus (SCBA) fails, the technician can remove the SCBA face piece and breathe the in-suit expired air while exiting the incident or awaiting rescue. Objective. To determine the composition of expired air present within an encapsulating suit during exercise. Methods. Subjects (n = 4) walked on a motor-driven treadmill (3.2 km·h–1) for 30 minutes while wearing encapsulating PPE and SCBA. Oxygen (O2) and carbon dioxide (CO2) levels within the PPE were monitored. Subject vital signs and end-tidal CO2 (EtCO2) were continuously monitored. After treadmill exercise, rescue air from an external source was introduced into the suit. Results. Mean oxygen levels inside the PPE fell b...