Underground railway fires are not common but the result could be catastrophic. Being economic, rapid and comfortable, underground railway is a popular transport system over the world. The Underground Railway is one of the most dense transportation media carrying huge patronage, though there was no serious fire incident.
Tenability Limit of Gas Temperature and Concentration
During evacuation, the tenability limit of gas temperature and concentration in the compartment would be critical to the evacuees. For high temperature exposure effect, the critical temperature for different exposure condition list as below for reference.
| Type and period of exposure | Effect | Temperature (0C) |
| Radiation | Severe skin pain | 185 |
| Convection (30 minutes) | Hypothermia | 100 |
| Convection (<5 minutes) | Skin/lungs burn by hot gases | 120 |
| Convection (<1 minute) | Skin/lungs burn by hot gases | 190 |