Wood Dust, Deflagrable : Wood particulate with a median diameter of 420 microns or smaller (i. e. , material that will pass through a U. S. No. 40 Standard Sieve), having a moisture content of less than 25 percent (wet basis)
NFPA 664 Standard for the Prevention of Fires and Explosions in Wood Processing and Woodworking Facilities, 2002 ed. (Std: Prev of Fr and Explo in Wood Procss and Woodworking Fcilty - Amer) {339 NFC}