Work out dust explosion risk instantly with clear inputs, formula shown and shareable results.
A dust explosion needs a cloud above the minimum explosible concentration, typically 20 to 60 g/m³, plus an ignition source and confinement. Severity is graded by the Kst index. The larger danger is usually secondary: a primary event disturbs settled dust, and a layer of just one millimetre across a room provides enough fuel to destroy the building.
Explosibility
Concentration ratio = airborne concentration / minimum explosible concentration
Severity class
St 1 up to Kst 200, St 2 to 300, St 3 above 300 bar·m/s
Preliminary estimate only. Dust explosion risk assessment, area classification and explosion protection must be carried out by a specialist to the applicable standards.
Concentration ratio = airborne concentration / minimum explosible concentration. A dust explosion needs a cloud above the minimum explosible concentration, typically 20 to 60 g/m³, plus an ignition source and confinement.
Dispersed through the room volume, a one millimetre layer over the floor produces a cloud well above the minimum explosible concentration. It is the standard housekeeping threshold for that reason.
This calculator takes 4 inputs: Airborne dust concentration, Minimum explosible concentration, Dust explosion index Kst, Dust layer thickness on surfaces. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.