Tuesday, October 20, 2009
Initially when reading the recent news account of a worker that ignited flammable vapors causing an explosion while using a hand grinder to cut bolts embedded in the floor, it had not donned on me the gravity of the situation. That was until Jeffrey C. Nichols, President, South East Fire Prevention, Inc sent me an email this morning reminding me it could also happen with combustible dust. That is true, combustible dust provides explosive atmospheres just like flammable gases, vapors, liquids, and mists.
In many instances combustible dust related fires and explosions have occurred due to hot work providing the ignition source. One news account mentions that there was a sign adjacent to work area, that the area was hazardous. The same sort of warning signage should also be in areas where combustible dust is generated. In the EU, the ATEX directives have a provision for such signage. In the USA an OSHA combustible dust rulemaking is in the process and hopefully a provision of warning signage in communicating the risk from combustible dust explosions or fires will be included in the combustible dust rulemaking.
It is essential that prior to any hot work being conducted that a job hazard analysis be conducted evalauting the risk from potential fires and explosion. This ensures that a hot work permit includes all the potential ignition and fuel sources in managing the risk.