S2E01 | Pre-evacuation time distribution in fire safety engineering

Uncovered Witness: Fire Science Revelations

Welcome to Season 2 of Uncovered Witness: Fire Science Revelations! This season, the show's theme is Humans as part of a fire safety engineered system. In this series, we will unravel our understanding of human behaviour in fires and how this complex behaviour may be accounted for in the fire-safe design of buildings. Our understanding of the occupant response, decision-making process and biases may influence our design of exits and improve (or impede) the egress process.
In the first episode of this series, we cover the approach used to account for complex human behaviour in assessing the Required Safe Evacuation Time (RSET). This is commonly done by accounting for a delay in the evacuation process that is a product of complex human behaviour between receiving a fire cue and making the decision to evacuate.
Human behaviour may be considered repetitive over similar populations and occupations despite the complexities. This allows us to study this process from a statistical perspective—on average, how long does it take for people to respond to specific cues in specific circumstances? The answer is not a single number but a population-wide distribution of the pre-evacuation time, which can then be a useful input for our calculations and modelling.
In this episode, we discuss the history of this approach, the data sources and their validity. We also cover how cultural and societal context may influence the resulting time distribution.
Useful links:

• The pre-evacuation Database research paper mentioned in the podcast episode.
• Fire Science Show episode 134 - interview with prof. David Purser
• The standard widely referred to in the episode was BS PD 7974-6, available to purchase through the BSI

Guests featured in this podcast episode:

• Prof. Daniel Nilsson, University of Canterbury, Halliwell Fire Research
• Prof. David Purser - highlights from the episode 134 of the Fire Science Show

This show is produced by the Fire Science Media for Halliwell Fire Research. Executive producer - Monika Węgrzyńska, scripting and production - Monika and Wojciech Węgrzyńscy, sound engineer - Mikołaj Jarząbek. All rights reserved. 2024.