Minimum Explosible Concentration (MEC) 3 : The minimum concentration of a combustible dust suspended in air, measured in mass per unit volume, that will support a deflagration
NFPA 654 Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids, 2006 ed. (Std: Prev of Fr and Dust Explo from the Mfg, Procss, and Hndlg of Comb Particulate Solids - Amer) {337 NFC}