Test methods for fire hazards of construction plastics

This report studies the applicability of three small scale methods ISO 5657 (Fire tests -Reaction to fire - Ignitability of building products), ASTM D 3014 (Flame height time of burning and loss of weight of rigid cellular plastics in vertical position) and NT FIRE 013 (Plastics-candle like combustion, minimum oxygen concentration) in testing of building plastics. The small scale methods are compared with each other and with burning crib tests in larger scale. Eight rigid cellular plastics containing phenolic, polyurethane, polyisocyanurate and polystyrene were tested in each method. Also three additional phenolic cellular plastics and three PVC coverings were tested in two small scale methods. The results show that there is no strong linear correlation between any of the small scale methods or the larger scale, but the building insulating plastics can by ISO 5657 be separated into similar groups (containing the same materials) as by the larger scale method. However, as the reproducibility of the results is not very good, 95 % confidence interval + 15,6 % on average, and as there is no stronger correlation with the larger scale results ISO 5657 is not strongly recommended as a primary test for classification and in quality control. Neither of the two small scale tests can be used as a preliminary test of ISO 5657, or instead of it, because of weak correlation.