Experimental analysis of required ignition times of unattended incidents in kitchens

Abstract

Kitchen fires represent a significant portion of residential fire incidents worldwide, with statistical data identifying unattended cooking as a leading cause. These fires often originate from oil or grease in cookware, with heat and smoke from the initial fire plume igniting nearby secondary items. This progression can escalate into full-scale fire involvement, particularly under ventilation conditions that promote fire growth. This study investigates the behaviour of unattended kitchen fires through a series of full-scale experiments, focusing on the duration of the primary ignition source and the potential ignition times of secondary items. A fully furnished kitchen mock-up was constructed, and thermocouples were installed on various surfaces to record temperature data. Twelve tests were conducted using sunflower oil in quantities ranging from 50 to 300 ml as the ignition source. Regardless of the oil quantity, temperatures rose rapidly at the start of the flame period, peaking within two minutes. Larger oil quantities produced higher peak temperatures and extended flame durations. Thermal effects were concentrated on the upper backsplash, under the range hood, and along the lateral surfaces of adjacent cabinets.