Fire Safety Science Digital Archive

By use of test data from the Cone Calorimeter bench scale test and two full scale fire tests (IS0 Room Comer Test and CSTB Room Fire Test), relationships between smoke test data for the two scales were investigated. The study was based on test results for 38 products. Bench scale and full scale smoke production were normalized to either area burnt, mass loss or heat release and then compared. The most interesting parameter was smoke production per heat release, and for the products tested in the CSTB Room Fire Test there was found good correlation and a correlation coefficient of 0.99. It was shown that smoke production in full scale was only about 45-60% of what was found in bench scale, and this is probably due to secondary combustion which occurs in the hot smoke layer. Before a secondary combustion occurs, the room fire is ventilation controlled and can produce more smoke than is found in bench scale. Thus the full scale fire influences smoke production in a way that may hinder relationship between bench scale and full scale smoke parameters. Full scale smoke test data from the IS0 Room Corner Test were difficult to calculate, due to problems with finding the net heat release from the burnt products and the estimated burnt area. A one-to-one relationship between bench scale and full scale for the average effective heat of combustion (hhWg) was found and the plot obtained a correlation coefficient of 0.99. Since direct mass loss measurements are not done in these full scale tests the smoke extinction area (SEA) is actually identical to smoke produced per heat release (TSP/THR).