Fire Safety Science Digital Archive

A series of experiments have been carried out on the burning of arrangements of wooden dowelling in atmospheres of reduced oxygen concentration. Using nitrogen and carbon dioxide as diluents a reduction of rate of flame spread with reduction in oxygen concentration was noted for both upward and horizontal propagation; the relative effect, however, was much larger with horizontal propagation. Extinction was obtained when the oxygen concentration was reduced to values between 13.2 per cent and 19 per cent depending on the direction of propagation and the arrangement of the dowelling. The effect of reducing the oxygen concentration is more marked when the process of flame spread depends on radiant heat transfer than when it depends on convective heat transfer.