Abstract
The concept of extinguishability as a measure of textile flammability is reviewed. Definition and determination of extinction oxygen index enables a parameter to be defined from which the effects of ignition time and fabric structure may be removed. This so-called extinction oxygen index (EOI) and the derived value at zero ignition time [EOI]0 more exactly define the burning/nonburning fabric boundary than does the more widely used limiting oxygen index (LOI). This first paper reports the determination of EOI and [EOI]0 values for a series of cotton fabrics in the temperature range 20–200°C. The influence of the various fabric parameters of area density, air permeability, sample thickness, bulk density, and moisture content was investigated. The advantages of using the EOI rather than the LOI concept as a measure of textile flammability is indicated in the discussion of the results of this study with reference to previous work concerned with LOI data for cotton. In particular, the significance that environmental temperature has on EOI and related parameters reported here and previously reported LOI data is discussed in terms of various published models which define the burning/extinction threshold.