Comfortable SCBA Weights from Biomechanical Models for Firefighting Tasks

Firefighters are required to use a self-contained breathing apparatus (SCBA) for respiratory protection when engaged in a variety of firefighting duties. While the SCBA provides crucial respiratory support and protection, it is also cumbersome and heavy. Questions have arisen to address the current weight limitation listed in 42 CFR Part 84, which mandates the maximum weight of 16kg (35.2 lbs.) for an SCBA system. The objective of the overarching study is to inform a maximum comfortable SCBA weight by developing static and dynamic biomechanical models and collecting physiological burden and postural stability data to evaluate stressors for firefighting tasks. This paper presents data from the static models. Eight representative firefighting tasks (stair climb, hose carry, weighted carry, rope pull, dummy drag, hammer slam, overhaul, and hose advance) were used in the biomechanical models. Maximum comfortable SCBA weights were calculated based on three biomechanical models (abdominal extension/tension, lateral extension/tension, and abdominal rotation). This study found that the maximum comfortable weight for an SCBA was 39 lbs. for the static postures of interest. Further studies with human subjects to investigate the SCBA weight limit by using physiological burden and dynamic models are underway and will provide crucial data to inform updates to the current weight limits for SCBAs allowing more features and extended durations of these devices without compromising user safety, performance, or comfort.