Fire Safety Science Digital Archive

This paper presents scientific basis for establishing safety evacuation countermeasures, i.e., evacuation plans and escape signs etc., in case of fire in Japan. Especially issues of physical and physiological effects of fire smoke on evacuees are addressed. This paper consists of three headings, in order of my research life: 1) visibility, 2) characteristics of human behavior, and 3) development of an "Intensive System for Escape Guidance" in fire smoke. In Japan, since the 196OVst,h ere have been an increasing number of people killed by smoke in fire resistant buildings. Toxic gases and/or depletion of oxygen in fire smoke are the final death causes of those victims, however many evacuees are trapped in early stage of fire by relatively thin smoke and loss of visibility is an indirect but fatal death cause. In this reason, the relations between the visibility and optical density of fire smoke were examined by experiments, and practical equations were proposed. For further understanding of human behavior in fire smoke, many fire investigations were conducted by interviews and questionnaires to evacuees. Also experimental research was conducted with subjects under limited fire smoke conditions, and a threshold of fire smoke density for safe evacuation was examined. Through many field investigations of fires, it is found that an effective guidance sign system is required for safety evacuation in fire smoke. Development of conspicuous exit signs, using a flashing light source was one of my first research works to improve evacuation under smoke filled conditions. A new type of the escape guidance in fire smoke by continuously traveling, flashing light sources was developed and its effectiveness was examined in a smoke filled corridor. This innovative technology for safe evacuation is now in practical use in Japan.