When considering the hazards associated with combustible dust, most organizational leaders are aware of the direct impact that a dust explosion could have on their facility. Even when it is understood that hazards exist within a system and that protection measures have been recommended, a flawed cost-benefit analysis could result in no action being taken.
This is especially true when the recommended action involves the retrofit of engineered protection systems (i.e. explosion vents) onto existing processing equipment such as a dust collector, dryer or bucket elevator. In some cases, it is possible the price for protection could exceed the original cost of the protected equipment itself. The facility is probably even insured for damages caused by such a scenario.
But what is often not accounted for in such a cost-benefit analysis is what comes after an incident. The days and weeks following a dust explosion or flash fire are often riddled with unforeseen obstacles and losses which can accumulate into huge expenses stemming from the original incident.
1. Equipment & Facility Damage
This is often the most obvious and accounted for loss as combustible dust hazards are addressed. The cost of your spray dryer or packaging building is a tangible and concrete asset that can be easily identified when determining the risk associated with a fire or explosion. But accounting only for the equipment or the building itself will not capture the full picture when it comes to total costs following an incident.
2. Primary Accident Injuries/Fatalities
Across industries, the stated priority for almost all manufacturing operations is SAFETY FIRST. The risk associated with a dust explosion is literally a matter of life and death for the employees (and contractors) that work in the processing area on a daily basis. Injuries that occur during the event can include thermal burns when exposed to a fireball; head/neck injuries due to falling debris or falls from height; and broken bones or sprains sustained while evacuating. When aggravating circumstances are introduced (i.e. accumulations of combustible dust or lack of proper evacuation plans), these injuries will become more severe and occur in higher frequency.
3. Lost Production
Following any accident at your facility, the most substantial and lasting consequence is the interruption to production. Both unscheduled downtime and diversion of operations resources to assist in cleanup/repair can prevent your facility from putting out product for days and even weeks following a dust explosion.
4. Product Quality
Lost product is bad enough in the wake of a combustible dust fire or explosion, but then you learn that the product currently in your processing equipment could be off-spec! Even product found in storage silos in the warehouse could be compromised due to the high temperatures, combustion products, and water (or other suppressant) used to put out the flames.
Following a combustible dust incident, it is possible for the contents of the entire process to be lost due to quality concerns (especially if the product is pharmaceutical or food grade). The risk of pushing through contaminated or off-spec product will often dictate that the current batch be scrapped or sold as off-grade.
5. Increased Contractor Work On-Site
While the operations and quality teams attempt to sort out how to provide the required product in the interim, the maintenance staff is charged with getting the process back up and running as quickly as possible. In almost all cases, this means brining in outside contractors to perform repairs and change out consumable parts that were impacted during the dust explosion.
For small events, it is common that filter bags, gaskets and belts are replaced; valves are re-built; and other damage is repaired. Larger events may require contractor crews to re-build full systems or sections of the plant before normal operations can resume. This increase in on-site activity introduces new risk to your operation on top of the direct labor costs.
6. Secondary Injuries During Repairs
It should not come as a surprise that an increase in non-routine repair work and presence of contractors would result in more injuries on-site. Try as we might, there is just no avoiding the probability that more work begets more injuries.
Although it might not be accounted for or related back directly to the initial event, these injuries resulting from efforts to get a process back on line following a dust explosion are costly. Just think about the elevated work, hot work, confined space entry, electrical work, and other hazardous activities are required to start a process up following a combustible dust event. Would these activities be required if not for the initial event?
The damages caused by a fire or explosion reach far beyond the cost to repair the equipment or building which is affected, and often impact a facility in ways that insurance is not able to fully mitigate. For these reasons, the real losses from an industrial accident can be difficult to accurately depict in a cost-benefit analysis model.Specific actions, such as completing a Dust Hazard Analysis (DHA), ensuring adequate dust collection, the use of properly rated vacuum cleaners on combustible dust, and implementing explosion protection systems can help to reduce the impact of an event at your facility. Taking responsible steps toward combustible dust safety will ensure that your facility remains safe, your people remain focused, and your process keeps running.