Effective September 7, 2020, all companies that handle combustible dust must have a completed dust hazard analysis in accordance with NFPA 652. Many facilities are still unclear about this requirement, so let’s look at the requirements of NFPA 652 and a few simple tactics to help your company with compliance.
A dust hazard analysis (“DHA”) is defined as “a systematic review to identify and evaluate the potential fire, flash fire, or explosion hazards associated with the presence of one or more combustible particulate solids in a process or facility.” (NFPA 652, The Fundamentals of Combustible Dust, 2019)[emphasis added] The operative word in this definition is “systematic”. A facility must undertake a careful evaluation to first determine if it has combustible particulate solids, including but not limited to dusts, by determining the combustibility of the material. This can be done in many ways, including use of historical facility data, published data representative of your site’s process conditions and materials, or analysis of representative samples. Absence of prior fires or explosions is simply not enough to justify a non-combustible determination. Be sure to maintain documentation of this information.
In the event that analysis of your materials is necessary, one should follow the procedures from the standard to determine combustibility and explosibility of the materials using appropriate screening tests. Where the material is handled and there are changes in size or configuration of the material, be sure to collect various samples, including samples of different steps in the process if needed. The Standard provides a simple flow chart to assist in the determination of combustibility/explosibility, and to help you understand what to do with that information.
A dust hazards analysis is a critical step in determining the risk to a facility. An evaluation of fire, deflagration, and explosion hazards must be undertaken by a “qualified” person. Be careful in selecting an individual or firm to address these matters. Not only should this individual be qualified from an academic standpoint, but he or she should also be qualified from a practical or experiential standpoint. It is important that the individual selected have a demonstrated ability to address “the problems related to the subject matter” (NFPA 652, 2019). Hiring an inexperienced person to assist you with your dust hazards analysis can have life-threatening consequences. A comprehensive DHA includes a review of process conditions, process systems, and building or building compartments. Once completed, the DHA and associated elements will be used as the basis for compliance with the applicable NFPA dust standard, and will be used to develop a mitigation plan to manage the hazard. NFPA 652 is used to provide the fundamentals, but those who work with specific products such as metals, grains, wood or sulfur will be led to the respective standard for more detailed information. If not one of the listed hazards, then the user should refer to NFPA 654, Standard for the Prevention of Fires and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids.
Regardless of the material processed, management of combustible dusts is a unique situation, requiring specialized expertise and knowledge, as well as a keen insight into processes and process controls. It is not a theoretical practice, but rather one that challenges the best minds. For more information about the management of combustible dusts or the completion of a Dust Hazards Analysis, contact Peter Downing at pdowning@environmentsafety.com. Also, stay tuned for our webinar focused solely on conducting a Dust Hazards Analysis.
Peter Downing, CHMM, is a member of the Technical Committee on Combustible Metals and Metal Dusts, NFPA 484, since 2009. Pete is a degreed chemist who has worked extensively with combustible materials, including metals and metal dusts. Pete has served as a “qualified person”, taking the lead on numerous dust hazards analyses and working cooperatively with his industrial clients.
