Identifying Dust Explosion Risks – An Overview for Risk Managers

As a follow-up to our previous post about OSHA Dust Hazcom Guidance, controlling the risk of dust explosions in the workplace involves an understanding of the specific elements that go into creating a hazardous situation.  Risk managers are already familiar with the Fire Triangle, which is the combination of elements that together form the necessary building blocks for fire:  an ignition source, oxygen and fuel.  However, a dust explosion introduces two other elements into the equation.  These are the suspension of dust particles in the air, and the presence of a closed space that can confine and concentrate those particles to a dangerous level.

Evaluating the potential for these factors to come together in a workplace has to take into account not only typical business processes, but also any unexpected events which could introduce new factors into the mix.  Since there are 5 elements in the dust explosion formula, a work environment where at least three are present at any given time presents the risk that an accident on the site could add in the missing ingredients.  Consider the idea of a warehouse where barrels of dust-producing materials are kept.  While stored, the barrels themselves may present no particular danger.  However, should a shelving unit collapse, causing barrels to fall and split open, a considerable amount of hazardous dust could be thrown into the air where it could easily be ignited by the engine of a passing forklift – or perhaps even sparks produced by the further collapse of the shelving.

While the above situation may seem overly elaborate, it serves to demonstrate that it is unlikely that any areas of a production facility remain “explosion hazard free.”  The key when evaluating risks is to determine the degree of danger that they pose and then plan accordingly.  If one part of a building or production floor is known to offer an increased risk of dust explosion, then workers can be trained in how to mitigate the chances of an incident occurring, as well as how to respond should one present itself.  This should be on top of the general dust explosion training that all workers need to undergo when employed in an industry that produces dangerous amounts of explosive dust.

Risk managers can divide facility evaluation across a few different criteria.  It is of course important to study the Materials Safety Data Sheets of all chemicals and materials present during business in order to determine if they pose a dust explosion hazard.  Keeping track of where these materials are stored and how they are transported is also key.  Next, any processes which generate large amounts of dust, or even small amounts that could accumulate over time need to be identified.  Hidden areas, such as crevices behind machines which could accumulate dust unnoticed must be noted, along with any open areas which may have dust tracked into them, or which may provide for the slow air saturation of dangerous dust particles.  Finally activities which push dust into the air – ventilation equipment, saws, vehicle exhausts – need to be accounted for, along with the varied sources of ignition that are typically scattered around a modern facility.