An investigation has been carried out of the limiting oxygen index (LOI) test. A review of the literature shows that, although there is abundant information on the test, it is not clear that its results correlate well with those of any other test, or indeed with those of real fires. Theoretical considerations indicate that the test could be improved by using it with bottom ignition rather than with the standard top ignition. A number of materials were tested in the cone calorimeter and in the LOI, and various correlations were attempted. In general, correlations between some of the cone calorimeter properties measured and the inverse of the LOI made sense. These correlations were not, however, sufficiently sensitive, even when investigating small effects on a single base polymer system, to justify using the LOI as a proxy for the cone in any way. The LOI is likely to continue to be used extensively. This work suggests that quality control and, possibly, mechanistic or other flame-retardant additive studies, are its only applications where the results can be justified.

Oxygen index: Correlations to other fire tests

Handbook of building materials for fire protection , Handbook of building materials for fire protection , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

Handbook of Building Materials for Fire Protection

Characterization of thermal properties and analysis of combustion behavior of PMMA in a cone calorimeter

This work revisits the classical problem of flame spread on solid fuels, to incorporate finite width effects. It is argued that in addition to the excess pyrolyzate [ P.J. Pagni, T.M. Shih, Proc. Combust. Inst. 16 (1978) 1329–1343.], a fraction of the fuel also diffuses to the sides and changes the amount of fuel available to participate in flame spread as excess pyrolyzate. This diffusion ( M ˙ Z ′ ) is significant for narrow fuel samples (width M ˙ Z ′ is calculated as a function of xp. The significance of M ˙ Z ′ in changing the flame height, and flame spread rate is explained. Experimentally measured flame heights show good agreement with the current theory. Previous work in two-dimensional flame spread theory and correlations are compared with the current analysis.

Upward flame spread on a vertically oriented fuel surface: The effect of finite width

In this paper, flammability parameters associated with the igni tion, combustion, and fire propagation processes and their usefulness for the development of fire resistant materials are discussed. The flammability param eters discussed are: (a) Critical Heat Flux (CHF) and Thermal Response Param eter (TRP), associated with ignition, (b) Heat Release Parameter (HRP) and Fire Propagation Index (FPI), associated with combustion and fire propagation.

S.D. Ogden

Papers

Fire behavior of polymethylmethacrylate