CHST Worksite Audit Practice Test

Ignition of a dust cloud hinges on having a combustible fuel mixed with enough oxidizer to sustain combustion. In other words, there must be both sufficient oxygen in the air and enough dispersed dust to serve as the fuel. If either the oxygen level is too low or the dust concentration is below the flammable range, ignition is unlikely even if an ignition source is present. The size of the dust particles, impurities, the strength of the ignition source, and the dust’s temperature influence how readily ignition occurs or how severe the burn is, but the fundamental gatekeepers for ignition are the availability of oxygen and enough dust to form a combustible mixture.