A probabilistic thermal radiation analysis of cooking hob separation distance in open plan kitchens

Cooking oil fires present a hazard to the occupants of residential flats with open plan kitchens where the means of escape passes fixed cooking appliances. Recent guidance has proposed a separation distance of 1.8 m from a hob/stovetop, but the basis of this advice is unclear. This paper carries out a probabilistic thermal radiation analysis using the thermal fractional effective dose (FED) methodology to assess the likelihood that the specified separation distance will be exceeded. Statistical data collected from a previous survey of cooking oil usage is used to determine reasonable worst-case maximum heat release rate values as input to the point source model to calculate thermal radiation exposure. Occupant exposure times are assessed using walking speeds based on occupant demographics. The analysis suggests that the 1.8 m criterion equates to approximately a 99th percentile where there is no cap on the heat flux that an occupant can tolerate. This falls to the 88th percentile when the maximum tolerable heat flux is capped at 2.5 kW/m(2) to account for vulnerable occupants.