Factors that influence the explosiveness of wood dust, like particle size distribution, moisture content and
microscopic structure, have been characterised. Sawdust flammability has been tested in a Hartmann tube. The
Minimum Explosive Concentration and Minimum Ignition Temperature of dust clouds and layers have also been
measured. Dust granulometry linked to the regularity of its structure and moisture are the essential parameters to
generate or not an explosive atmosphere. Smaller particle size dust with a lower moisture content is much more
likely to create an ignition and/or explosion risk. The samples have been classified into two groups, those
collected from cutting processes and those found in the ventilation ducts or deposited in the facilities. The most
dangerous samples are those from Group 2. In some cases, dust samples up to 35 % moisture or with particle size
greater than 500 µm at maximum dryness are able to produce an explosion.
