The manufacturing or processing of materials such as wood, plastics, fossil fuels, food, paper, textiles, metals and chemicals can generate dust that is combustible. And it is well-known that combustible dust collected in visible areas or on high surfaces is a source of industrial fires and explosions. But did you know that there is more dust hidden inside the ductwork? Even with cleaning outside the ductwork, combustible dust that has accumulated inside the duct creates a confined dust explosion hazard.
According to the Dust Explosion Pentagon, one of the essential parts to creating the situation for a combustible dust explosion is containment. And what better environment for this to happen than inside of a facility’s ductwork.
Dust created from the manufacturing process is dispersed throughout the facility and over time, is brought into the ventilation ductwork as air flows through the building. The dust will settle in sections of the duct where there is a bend or anything that might prevent the dust from continuing to flow through the duct. The constant movement of air causes potential ignition sources to be drawn into the ductwork. Sparks and embers can stay hot for a long enough time, and when sucked into the HVAC system can come into contact with the dust or a piece of metal traveling through the ductwork can scrape the side and cause an ignition spark. The dust moving through the duct also creates a buildup of static electricity, which can have the potential to create an explosion.
We can’t stress enough the importance of making sure your facility’s ductwork is cleaned and free of any combustible dust accumulations. Not only do dirty ducts create health issues for your employees, but they also create a safety and confined dust explosion risk.