Environmental, Health and Safety Services

Can "dust" cause an explosion in a confined space?

YES.  The type of "dust" that can result in an explosion is that from any material in its bulk form that will burn, such as coal, cotton, grain, sugar, etc.  It does not include dust from soil, which will not burn in its bulk form.

Although there is no set parameter for excessive dust in a confined space, there is a rule of thumb that can be followed.  When the concentration of dust in the confined space is such that vision is obsured at a distance of 5 feet, it is considered to be potentially explosive and should be controlled through ventilation, wet methods, etc.

In order for dust to explode, the right concentrations of dust and oxygen must be present, in addition to an ignition source, which could be electrical equipment, metal striking tools, illegal smoking, etc.