Combustible Dust 2 : A combustible particulate solid that presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations, regardless of particle size or shape
NFPA 1 Fire Code, National Fire Protection Association (NFPA), MA, USA 2009 ed. https://law.resource.org/pub/us/code/ibr/nfpa.1.20 03.pdf, (Code: Nat Fire Protection Association Fr&LfSf Requir - Amer) {171 NFC}