Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing and Handling of Combustible Particulate Solids 

NFPA 654 offers guidance on best engineering practices associated with combustible dust.  Combustible dust is any finely divided solid—such as flour, wood dust, or aluminum dust—that will explode when dispersed in air and ignited.  The standard includes information on avoiding dust explosions through both facility design and housekeeping.  Additionally, information on controlling ignition sources and explosion mitigation strategies is provided.  Optimally, dust should be prevented through effective housekeeping measures.

Requirements of NFPA 654 include information on facility design, process hazard analysis, basis for deflagration protection, and an analysis of the physical and chemical properties of the given combustible dust.     

This standard is on a five year revision cycle; the 2006 edition is expected to be updated in 2011.  Changes expected to take effect in the revised standard include the following additions regarding Personal Protective Equipment:

• “Operators shall wear flame-resistant garments as specified in NFPA 2112 and any other personnel protective equipment required for protection against flash fire hazards during charging operations.”
• “Operating Plans shall include the use of flame-resistant garments as specified in NFPA 2112 for all exposed personnel when the design dust mass accumulation exceeds the threshold value determined per section 6.1” 
• “Operating and maintenance procedures shall address personal protective equipment (PPE) for tasks involving or handling of combustible dust according to the following: PPE shall include flame resistant garments in accordance with the workplace hazard assessment required by NFPA 2112: and
• Where a dust explosion hazard or flash fire hazard exists, flame resistant garments shall be required for all exposed personnel.”

The standard is available to view online at no charge or to purchase a downloadable copy:  http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=654