BS 7899-2:1999

Committees responsible
      Foreword
      Introduction
1 Scope
2 Terms and definitions
3 Methods available and hazards to be assessed
4 Options and reliability of methods for determining hazard
      to life
5 Toxic hazard assessment method using time-concentration
      curves for full scale fires: designed to estimate time to
      incapacitation for exposed humans
6 The use of small-scale test data for estimating toxic
      potency and toxic hazard
7 Application of toxic potency and toxic hazard calculation
      methods
Annex A (informative) Sensory irritancy
Bibliography
Figure 1 - Percentage frequency distribution of non-fire CO
           deaths
Figure 2 - Hazard analysis for a furniture fire
Table 1 - Comparison of the characteristics of hazard to life
          assessment method options
Table 2 - Reported effects of smoke on visibility and behaviour
Table 3 - Irritant concentrations of common fire gases
Table 4 - Lethal exposure doses of irritants contributing to
          asphyxia and lung damage
Table 5 - Simplified look up table for solutions to individual
          toxic gas FED equations for incapacitating exposure
          doses over a 1 min exposure time
Table 6 - Limiting conditions for tenability caused by heat
Table 7 - Lift threat analysis for the first 6 minutes of a
          furniture fire
Table 8 - Revised classification of fire types
Table 9 - Currently accepted 30 min LC50 concentrations for
          common fire gases
Table 10 - Toxic potency analysis of materials decomposed under
           non-flaming oxidative conditions in the NBS cup
           furnace
Table 11 - Toxic potency analysis of materials decomposed under
           early, well ventilated flaming conditions in the NBS
           cup furnace
Table 12 - Toxic potency analysis of materials decomposed less
           efficiently under early, well ventilated flaming
           conditions in the NBC cup furnace
Table 13 - Approximate lethal exposure doses (LCt50 gm-3min),
           and lethal concentrations (LC50 gm-3) for common
           materials under different fire conditions
Table A.1 - Mass loss concentrations of thermal decomposition
            products predicted to be painfully irritant
           (mouse RD50 gm-3)

Guides fire safety practitioners on procedures for the quantification of hazards to life and health. Procedures for calculating smoke obscuration, fire effluent toxicity and thermal components of fire hazard analysis to estimate time to incapacitation and death in fire are covered, as well as procedures to estimate lethal toxic potency from chemical analysis of small-scale combustion toxicity test atmospheres and for applying this data to toxic hazard assessments for fires.

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.