Evaluation of Fire Characteristics of Different Norway Spruce (Picea abies) Fractions in the Wood-Processing Industry

Wood-processing industrial facilities in which Norway spruce wood (Picea abies) is processed and where products such as sawdust, wood chips or wood are generated are considered high-risk operations from the perspective of fire safety and explosion hazards. This is due to the combination of combustible material, fine particulate matter, ignition sources, and the potential for dust explosions. In this article, we focused on three different fractions of spruce wood (Picea abies) commonly present in the wood-processing industry: sawdust, wood chips, and compact wood. Experimental measurements were carried out under laboratory conditions in accordance with ISO 871. Ignition temperature, flash-ignition temperature, and activation energy are key parameters that determine the susceptibility of spruce wood, sawdust, and wood dust to ignition. Fine wood fractions exhibit lower activation energy and lower ignition temperatures, which increases the probability of combustion initiation. The activation energy for spontaneous ignition of sawdust was 45.1 kJ·mol−1, compared with 66.5 kJ·mol−1 for compact wood and 31.9 kJ·mol−1 for wood chips. The activation energy for the flash point of sawdust was 48.5 kJ.mol−1, for wood chips was 36.8 kJ.mol−1 and for compact wood was 44.9 kJ.mol−1. In combination with airborne wood dust, these conditions create a significant potential for fire development and dust explosions in wood-processing industrial facilities.