Firefighter Physiological Responses To Increased Self Contained Breathing Apparatus (SCBA) Weight

PURPOSE: The purpose was to examine the effects of increased SCBA weight on firefighters’ physiological responses. METHODS: Ten healthy male firefighters utilized three SCBAs with various weights, performing two repeated bouts of four simulated firefighting activities at varying work rates. A commercially available SCBA (SCBA1) was modified to exceed the current weight limit by 2.3 kg (SCBA2) and 4.5 kg (SCBA3). Oxygen consumption, heart rate, and core temperature were continuously measured. RESULTS: Each parameter was analyzed using a repeated measures ANOVA with significance set at α = 0.05. Specifically, the three SCBA conditions were examined (SCBA1, SCBA2, and SCBA3). Table 1. - Peak values after completing simulated firefighting activities for peak rate of oxygen consumption (VO2Peak), peak rate of oxygen consumption as a percentage of maximal rate of oxygen consumption (VO2peak % of VO2max), core temperature rate of rise (Tco, RoR). Superscripts (i.e., 1,2,3) indicate significant differences from the SCBA noted in the superscript. Data are shown as mean (standard deviation). SCBA1 SCBA2 SCBA3 VO 2peak (O 2 ml/min/kg) 31.6 (7.3) 31.0 (6.6) 29.1 (5.8) VO 2peak % of VO 2max (%) 80.9 (11.4)3 79.6 (10.5) 74.8 (10.1)1 T co , RoR (°C/min) 0.037 (0.016) 0.038 (0.014) 0.040 (0.013) Table 2. - Heart rate for each bout of activity with three different SCBA weights. Heart rate data include peak heart rate across the activities (HRPeak) and peak heart rate as a percentage of maximum heart rate (HRPeak % of HRmax). Data are shown as mean (standard deviation). Bout 1 Bout 2 SCBA1 SCBA2 SCBA3 SCBA1 SCBA2 SCBA3 HR Peak (bpm) 177.5 (9.9) 181.8 (9.0) 173.5 (13.7) 180.8 (16.0) 174.6 (16.3) 179.1 (10.6) HR Peak % of HR max (%) 96.3 (6.0) 98.6 (5.7) 93.9 (3.9) 97.9 (6.5) 94.7 (8.3) 97.1 (4.7) CONCLUSION: Data indicated limited impact on the physiological responses of firefighters to the increased SCBA weight above current limits. Additional studies are needed to determine other impacts.