Fire Safety Science Digital Archive

Few people actually burn to death - the majority are overcome first by smoke and hot gases: it should be appreciated that these gases may leave the immediate fire area at temperatures in the region of 1000C and, although they will cool when mixed with the atmosphere of the building, they may still retain very high temperatures even when as much as 200 ft away: furthermore, even if cooled to a tolerable degree, the concentration of carbon monoxide and other toxic gases may still be lethal. As little as 0.5 per cent carbon monoxide in the atmosphere will cause death within minutes - and greater concentrations than this would be common. Thus, on escape routes the immediate concern is with smoke and the movement of that smoke is very fundamental to the planning of the route itself.