Flame spread over plastic materials in flashover room fires

Flame spread over the surface of plastic samples under a flashover room fire will be discussed in this paper. Two plastic samples on polyvinyl chloride and polycarbonate were selected and tested. These materials are commonly used in the market but difficult to ignite under accidental fires. Full-scale burning tests were carried out in a room calorimeter in China. A bigger pool fire of diameter 1 m was set up to simulate an arson fire to onset flashover. Fire behaviours of the two plastic samples were assessed. The heat release rate, upper layer gas temperature profiles and heat fluxes at floor level were measured. Ignition behaviour, surface flame spread, melting and charring of the materials were observed. Note that these samples were basically not ignited while testing under a smaller pool fire of size 0.35 m × 0.35 m. The differences in burning under a flashover fire and an accidental fire must be watched in fire hazard assessment.