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Can fatal fires be avoided? The impact of domestic smoke alarms on human safety

Kjell Schmidt Pedersen1 and Anne Steen-Hansen2
1 SINTEF NBL as, Trondheim, Norway
2 Norwegian University of Science and Technology

This paper presents a summary of the findings from projects at SINTEF NBL concerning the human safety aspect in fires, focusing on fire safety in domestic houses. How domestic smoke alarms affect the safety is chosen as a term of reference. Results from statistical surveys of fire deaths in Norway compared with other countries are used to describe who dies in fires. The use of and requirements for domestic smoke alarms in different parts of the world is briefly presented. The sensibility of ionic and optical smoke detectors in smouldering and flaming fires are analyzed, and an evaluation of the effectiveness of the two detector principles is made based on the test results and expected frequencies of these types of fires. Available time for evacuation is discussed based on expected time to untenable conditions, expected time to flashover, expected time to intervention from fire brigades, and the expected response time for smoke alarms. Different needs to evacuate different groups of occupants (children, elderly people, disabled) are also discussed. An analysis shows that the Norwegian requirement of domestic smoke alarms is highly cost effective. In Norway between 40 and 60 people die in fires every year, and it is estimated that 10 lives is saved every year because of installed domestic smoke alarms. There is, however, an improvement potential for the effectiveness of domestic smoke alarms. Detectors and alarms can be improved technically, requirements to power supply can be set, the installation can be optimized and the extent of use can be increased. All these improvements will increase the probability that an installed smoke alarm really is functioning in case of a fire, both concerning detection and alarm.

Key words: Fire safety, fatal fires, smoke alarms