Lyon et al from an interesting study by comparing the fire properties of several polymers between MCC and TGA proposed that the controlling factors for burning of polymeric materials are surface temperature of the condensed phase and the presence of combustibles such as fuel/air mixture. The minimum (critical) value of the surface mass flux m(cr) (kg/m2.s) or the rate of heat released by combustion of the fuel/air mixture per unit area of burning polymer, Q(cr) (W/m2) were shown to be the primary factors for gas phase ignition. He explained that for fire, mass flux, which measures the formation of volatile compounds and the heat released as a result of their combustion, is crucial for determining the ignition temperature. Lyon showed that the mass flux and the surface ignition temperature could be determined using the first derivative of non-isothermal single point TGA measurements (DTG).