Mitigation of firefighters’ skin burn injuries utilizing auxiliary measures

Abstract

The improvement in the thermal resistance of firefighter’s outer garments has been traditionally achieved with the implementation of phase change materials or aerogel as an added protective measure. This study proposes supplementary novel cost-effective measures to enhance the thermal resistance of conventional firefighter outer garments. The proposed measures consist of auxiliary protective layers of meta-aramid fabric of a plain weave and a honeycomb structure. A custom built vertically oriented bench-scale apparatus was used to simulate extreme to life-threatening fire environments characterized in terms of an incident radiative flux of 84 kW/m2 and 126 kW/m2. The fluctuations in experimental heat flux density were treated by employing a Gaussian empirical model. The heat dissipation rate within the skin layers was predicted with a numerical model based on finite element methodology. The skin burns were classified with Henrique’s integral. The conventional outer garment when exposed to 84 kW/m2 and 126 kW/m2 resulted in a superficial second and third-degree burn. The auxiliary layers, in conjunction with the outer garment, mitigated second and third-degree burns. The meta-aramid fabric of a plain weave exhibited better thermal resistance than the honeycomb structure layer. The proposed measures reduced the epidermis temperature by 32%. An inner garment made of meta-aramid fabric is recommended to be worn concurrently with an outer protective suit for severe fire incidents due to its relative ease of use. Honeycomb structure layers are not recommended due to their weak structure and restriction in mobility.