Influence of radiation mode and intensity on the protective performance of firefighting boots

In the process of firefighting and emergency rescue, firefighting boots are one of the most important personal protective equipments (PPEs) for firefighters to protect their feet and legs from thermal radiation injury. In this work, the self -designed long-term thermal radiation setup was employed to measure the critical failure temperature for firefighting boots with various radiation intensities and reveal the performance influence of radiation intensity on critical parameters, including the temperature rise inside or outside, hardness and mass loss of firefighting boots, when radiating from the front, the side or all around. The Henriques Burn Integral (HBI) was adopted to predict second-degree skin burn injury. The results show that with the radiation intensity increasing, the temperature inside or outside increases, and the hardness and mass of firefighting boots decrease. The declined magnitude of hardness goes down as the radiation time lapses. The second-degree burn time is advanced with the increase in radiation intensity. The second-degree skin burn time at 7 kW/m(2) is 166s and the predicted value was short. When the surface temperature of firefighting boots is up to about 140 C-degrees, the boots' toe color appears from bright yellow to scorched black, along with the bulge phenomenon, indicating its protection effect loss. At the identical radiation intensity, the temperature rises of the boots radiating from all around are larger than those of other conditions, and the maximum temperature of the inner surface of the boots radiating from the side at 7 kW/m2 is 1.9 times higher than that radiating from the front, indicating that the side of firefighting boots is weakness in an actual fire.