Here is a link to an article in this month’s Powder & Bulk Engineering Newsletter on the importance of monitoring combustible dust minimum explosive concentration (MEC) by Jack Osborn, PE of Airdusco Engineering & Design Services, LLC.
Minimum explosive concentration (MEC) is defined in NFPA 652 as the minimum concentration of a combustible dust suspended in air, measured in mass per unit volume (for example, grams per cubic meter), that will support a deflagration, such as an explosion or flash fire.
NFPA 652: Standard on the Fundamentals of Combustible Dust (2016)requires any facility that handles combustible dusts to determine each dust’s explosibility characteristics by testing it. Typically, this involves determining the dust’s KSt, Pmax, MEC, and minimum ignition energy (MIE), which is usually measured in millijoules (mJ), but other characteristics may also be important. These determinations are also critical information to have to perform a dust hazards analysis (DHA).