Ergonomic evaluation of the maximum water pressure for indoor fire-fighting via electromyographic and subjective methods

BACKGROUND: So far, there exists no internationally uniform regulation about the pressure limits of water used for putting out fires in multi-story buildings and large properties. OBJECTIVE: In this ergonomic study, the optimum and maximum pressure for the fire water supply was tested with respect to physically feasible and safe indoor fire-fighting. METHODS: In order to prove whether the nozzles work most efficient and a fire can be extinguished safely and precisely, 12 professional fire-fighters carried out simulated fire-fighting procedures under nearly realistic conditions. Throughout the entire test, the electromyographic activity (EA) from 7 muscles of the right hand-arm-shoulder system and one muscle of the left arm was recorded. Additionally, a special questionnaire had to be filled in to evaluate the subjective experiences when handling the nozzles. RESULTS: The EA – standardized through MVCs (Maximum Voluntary Contractions) – exceeded the limit for short-term static work for 3 muscles, especially when the pressure was 0.8 MPa and higher. The subjective ratings confirmed the measured physiological responses. CONCLUSIONS: The operating pressure for the fire water supply should not exceed 0.6 MPa (as compromise 0.7 MPa), in order to ensure safe and precise fire-fighting, and that the nozzles work most efficient.