Application of the NFPA 654 Dust Layer Thickness Criteria – Recognizing the Hazard

This paper is an overview of the NFPA 654 layer thickness criteria, including the 2010 TIA, and potential misinterpretations that could result in failure to recognize the hazard. Potential misinterpretations include allowing excessive floor area coverage, failure to account for layers thicker than the threshold, and failure to account for layers on equipment. The thickness criteria are applied to real-life example situations, illustrating application of the equations. Practical guidance is provided for establishing an initial housekeeping plan, monitoring accumulation, and documenting compliance for both existing and new installations.