Spark 4 : A moving particle of solid material that emits radiant energy due either to its temperature or the process of combustion on its surface. NFPA 654, 2000 ed
National Fire Protection Association, Illustrated Dictionary of Fire Service Terms, Jones & Bartlett Publishers, MA. USA 2006. https://books.google.com.kw/books?id=W0WIRa3Gl4QC& printsec=frontcover&source=gbs_ge_summary_r&cad=0# v=onepage&q&f=false, (Fr Srvc - Amer) {141}
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}