2.5.3. Cone Calorimetry

In addition to the LOI test, a cone calorimeter (Fire Testing Technology Limited, East Grinstead, UK) was used to gain additional information on the evaluation of the fire risk [32]. The cone calorimeter was adjusted to 50 kW·m⁻² as recommended in ISO 5660-1 and calibrated beforehand to minimize the influence of the test equipment and environmental factors. A weight change of the specimen, oxygen, and carbon dioxide in the exhaust was recorded and used to calculate total, average, and peak heat release rates. The heat release rate (HRR), average heat release rate over 180 s (HRR_180s), peak heat release rate (pHRR), and total heat release over the duration of ten minutes (THR_600s) was chosen for evaluation to represent the fire performance in terms of the contribution to fire growth [33].