Page 12 - OHS, May 2021

COMBUSTIBLE DUST
What to Do with Your Dust Hazard Analysis
A useful guide shows you how to evaluate and prioritize your DHA recommendations.
BY RUSSELL A. OGLE, PH.D., BRENTON L. COX PH.D. AND DAVID C. HIETALA PH.D.
If your facility manufactures, processes, blends, conveys, repackages, generates or handles combustible dusts, you will need a strategy. The purposes of this
article will be for identifying, evaluating and controlling these combustible dust hazards. The best approach for developing that strategy is to perform a dust hazard analysis (DHA). In fact, the combustible dust safety standards issued by the National Fire Protection Association (NFPA) are mandating that you must conduct a DHA for your facility. Although the NFPA is not a government entity, federal and state governments recognize their standards as generally accepted good practices. The deadline for conducting a DHA for most facilities handling combustible dust was September 7, 2020. For agricultural and food facilities, the deadline has been
extended to January 1, 2022.
There are many different approaches for
performing a DHA. NFPA 652 Standard on the Fundamentals of Combustible Dust presents general guidelines for the DHA and provides an example. Many additional references that describe various techniques and methodologies for DHAs are available including papers, presentations, webinars and books. Agricultural and food facilities may even be able to use the DHA checklist provided in Annex F of NFPA 61. A DHA will identify opportunities for improvement
in safeguarding people, equipment and buildings from dust explosions and fires.
The safety objectives here are very real. Dust explosions and fires can cause the loss of human life, create terrible burn injuries or destroy a business. Successful management of combustible dust hazards is important, but that does not mean that it is easy. Deciding what to do may be straightforward for some businesses. For a simple blending facility that handles one combustible dust, the number of DHA recommendations may seem quite manageable. Complex processing facilities with several combustible dusts, however, could be facing dozens, if not hundreds, of DHA recommendations. In these cases, many operators or owners may feel overwhelmed and left wondering where to begin. Are some of these recommendations more important than others? Does it make sense to implement each recommendation without modification, or should you consider alternatives? If a recommendation does not seem reasonable, do you still have to implement it?
In this article, we will provide some guidance on how to evaluate and prioritize your DHA recommendations. We discuss ways in which you can evaluate the merits of each recommendation, prioritize their implementation, monitor your progress and document the results.
Dust Hazard Analysis Recommendations
According to the methodology described in NFPA 652, it is the duty of the DHA team to offer recommendations where they consider additional safeguards to be warranted. Depending on the size and complexity of the facility, this may result in a DHA that contains dozens of recommendations. Categories of recommendations may include equipment-specific housekeeping, ignition source control, documentation and/or management systems.
It is common for a DHA to include a series of recommendations corresponding to apparent deviations from the approach prescribed within relevant NFPA standards. The NFPA 652 methodology, however, does not limit the types of recommendations that may be offered or provided. The DHA team considers them warranted, so the type and specificity of recommendations can vary widely. A prudent facility owner/operator hasanobligationtoevaluateandprioritize the DHA recommendations in a way that enables significant risk reduction in a timely, cost-effective manner. The facility, however, does not have an obligation to blindly accept all recommendations as written.
Accept, Modify or Reject?
Facility owners/operators will find that the decisions related to combustible dust hazards are rarely a binary choice
12 Occupational Health & Safety | MAY 2021
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