arpadveress 
Do you know it all?
Kst
This is the maximum rate of pressure rise (during the explosion test) and in simple terms is a measure of the violence of the explosion. Dusts are divided into various explosion classes on the basis of their Kst values. Dusts which are classified as non-explosive are classified ST 0.
Dusts with a Kst between 0 and 200 are classified as ST 1.
There are further classifications of ST 2 and ST 3 which apply to strongly or very strongly explosive dusts, however these classifications do not apply to the majority of feed materials used within the feed industry. A small number of micro ingredients can fall into the ST 2 classification and operators must ensure appropriate assessments are in place to identify these.
Kst is an important parameter to consider in the design of explosion protection systems such as relief vents.
Source: AIC
In case of dust hazardous environment it might mean you need to do testing of dust parameters for each project. Even changing suppliers shall be a reason for it.
It is vital that the plant must be kept free of accumulations of fine combustible dust. So cleaning is mandatory tool.
Keep up good work!
Arpad
