Burning behaviour characteristics of Toluene Diisocyanate (TDI) in flexible polyurethane foam fire environment

This paper describes the burning behaviour pattern of commercially important toluene diisocyanate (TDI) stored in cylindrical stainless steel containers and exposed to fire of flexible polyurethane foam stack. The behaviour of TDI in containers was examined through ad hoc laboratory fire tests in which the containers filled partially with TDI were placed in the sand bath heated to attain temperature of 200°C and 300°C separately and also when exposed to fire of flexible polyurethane foam stack placed by the side of TDI containers. First two experiments indicate the need of energy input and temperature range for auto-ignition and subsequent mass loss of TDI in the containers. The last three experiments describe the effect of foam stack fire on TDI filled in containers for their vaporisation, burning, distortion rupturing and bursting conditions of containers. After ignition TDI starts burning in a steady manner rather than vigorous manner without leaving any residue in the containers. It was found that the behaviour of TDI in containers when exposed to fire is governed mainly by the rupture (blowing off lid) characteristics of containers as a result of pressure rise of TDI within the containers. The paper also recommends good storage practices for safe storage of TDI in containers.