Dust Explosion Info is an information centre for Engineers, Safety Professionals and anyone involved with the potential hazard of dust explosions. The website is an excellent starting point for those wanting to know more about explosions; the physical characteristics of a dust explosion, the necessary conditions for an explosion to occur, potential ignition sources, dust explosion statistics, dust explosion prevention and dust explosion protection. Links to further information, books and design standards are provided to assist in a greater understanding of the subject and describe the simple measures that can be put in place to reduce the risk to factory workers.
Imperial Sugar Dust Explosion, 2008
The dust of many materials in everyday use such as coal, wood, cork, grain, starch, sugar, certain metals, some dyes and intermediates, and many plastics, can form explosive dust clouds. Explosions of such clouds have caused some of the worst industrial accidents. On February 7, 2008, a huge explosion and fire occurred at the Imperial Sugar refinery northwest of Savannah, USA, killing 14 and injuring 38 others (see picture below). Although the exact cause of ignition is unknown, the explosion started in a conveyor running underneath sugar silos. The primary explosion raised sugar dust that had accumulated on the floors and elevated horizontal surfaces, propagating more dust explosions through the buildings. Secondary dust explosions occurred throughout the packing buildings, parts of the refinery, and the bulk sugar loading buildings. The pressure waves from the explosions heaved thick concrete floors and collapsed brick walls, blocking stairwell and other exit routes. The resulting fires destroyed the packing buildings, silos, palletizer building and heavily damaged parts of the refinery and bulk sugar loading area.Most countries have laws that require the occupiers of factories to take steps to prevent and to restrict the spread of dust explosions. For nearly 20 years, European Directive 99/92/EC (also known as ‘ATEX 137’ or the 'ATEX Workplace Directive’) has set out minimum requirements for improving the health and safety protection of workers potentially at risk from explosive atmospheres. The text of the ATEX directive may be found here ATEX 137.See also onsite spraying in Slough
Hazardous area classification should be carried out as an integral part of risk assessment to identify places (or areas) where controls over ignitionsources are needed. Hazardous places are further classified into zones which distinguish between places that have a high chance of an explosive atmosphere occurring and those places where an explosive atmosphere mayonly occur occasionally or in abnormal circumstances.
Wood, coal, grain & sugar all have the potential to explode