This International Standard is intended to serve as general guidelines for the assessment of the fire threat to people. It encompasses the development, evaluation and use of relevant quantitative information for use in fire hazard and risk assessment. This information, generally obtained from fire-incidence investigation, fire statistics, real-scale fire tests and from physical fire models, is intended to be used in conjunction with computational models for analysis of the initiation and development of fire, fire spread, smoke formation and movement, chemical species generation, transport and decay, and people movement, as well as fire detection and suppression [ISO/TR 13387 (all parts)]. Aspects of the methodology described here are further amplified in ISO 13571 and ISO 13344. This International Standard is intended to facilitate addressing the consequences of a single acute human exposure to fire effluent. Other effects of the heat, gases and aerosols (such as effects on electronic equipment and effects of frequent, multiple environmental exposures of people), which are of importance in fire safety design, are addressed elsewhere.