This part of BS 7899 provides guidance for fire safety practitioners on methods for the quantification of hazards to life and health. It includes methods for the calculation of fire effluent toxicity, smoke obscuration and thermal components of fire hazard analysis for estimation of time to incapacitation and death in fire. Also included are methods for the estimation of lethal toxic potency from a chemical analysis of small-scale combustion toxicity test atmospheres and for the application of such data to toxic hazard assessments for fires.