Tenability

One of the most important issues during a fire in a tunnel is the possibility for a safe escape. During an evacuation, tunnel users may be exposed to toxic gases, radiation, high temperatures and dense smoke. In this chapter the most important consequences of exposure to gas components, radiation and convective heat are presented. Examples of asphyxiant and irritant gases and the effect on evacuating people are presented. Different models for estimating time to incapacitation and other endpoints due to exposure are discussed.