Page 14 - OHS, May 2021

EMPLOYEE TESTING
Dust explosions and fires can cause the loss of human life, create terrible burn injuries or destroy a business.
between implementing or not implementing a safeguard. In fact, further research often reveals multiple control and mitigation strategies are available to comply with relevant NFPA standards, and in some cases, there may be acceptable alternatives not described in the standard. Some recommendations may require significant modification to be consistent with facility engineering requirements, internal standards or to be compatible with other recommendations. As a result, some recommendations that seemed reasonable to the DHA team may not be possible or appropriate due to factors outside of its scope and purview.
Consider, for example, a hypothetical recommendation to: “Add fugitive dust collector socks to weekly inspection checklist.” This recommendation may prove to be straightforward, or further analysis and discussion with operations may reveal that the dust collector cannot be safely opened outside of the annual plant turnaround. In the latter case, it may be determined that an annual inspection corresponding to the plant turnaround is adequate, or a different strategy, such as a different inline fan may be necessary to achieve the desired risk reduction.
To perform such an evaluation, it is often necessary to assemble a different or larger group of stakeholders, involving management and often subject matter experts. This group should be empowered to accept a recommendation as written (when appropriate), to modify the recommendation (when necessary) or to reject the recommendation (given proper justification to do so). Where a recommendation is accepted or modified, the group should assign the associated action items to individuals or groups. In any case, it is recommended that the decision be documented to provide future stakeholders a better understanding of the resolution process.
Should You Manage Hazards or Risks?
Implicit to the consideration described above is a comparative evaluation of more than one approach to manage the same hazard, in other words, which actions will provide the “most bang for the buck.” Even strict compliance with the NFPA standards can generally be achieved through multiple pathways and very rarely can the hazard be completely eliminated. A facility, therefore, must decide how to best manage these hazards. This is where risk enters the decision-making process. To understand risk, one must first define the terms hazard, consequence and likelihood:
■ A hazard is a source of potential harm. Combustible dusts may present fire and explosion hazards as they have the potential to participate in fires and explosions.
refers to a negative (or hazardous) outcome associated with a dust fifire or explosion. ThThese consequences may be fifinancial, environmental, or health and safety related.
■ ThThe likelihood of a consequence is an estimate of the frequency or probability that the consequence occurs. Likelihood may be expressed qualitatively or quantitatively.
The concept of risk combines the consequences associated with a hazard and the relative likelihood of those consequences becoming manifested. In the context of NFPA 652, risk can be defined as a measure that combines “the likelihood, vulnerability, and magnitude of the incidents that could result from exposure to hazards” (see for example the definition of Risk Assessment, Section 3.3.41).1 In other words, risk provides a common point of comparison between an unmanaged hazard and various hazard management strategies that incorporate a consideration of uncertainty. The process of evaluating risk is called a risk assessment. This process shares some of the same steps as a DHA, but a risk assessment employs risk as a measure to evaluate and compare hazard management solutions.
Prioritizing Implementation for Risk Reduction
After recommendations have been considered and associated resolutions have been identified, it is often necessary to then prioritize implementation of recommendations. The DHA team may offer its own prioritization based on its understanding of the risk of hypothetical events that could be addressed by each recommendation and the extent to which risk reduction could be achieved by implementing each recommendation.
Ultimately, facility management has the final say on how action items are prioritized and must determine which risks are the greatest risks and which recommendations achieve the greatest risk reduction. To effectively prioritize recommendation action items, facility management should define its risk management objectives, such as exposure to plant personnel or other people outside the facility, to equipment within the facility or to the stability of facility operations. These objectives provide a prioritization structure that may or may not be directly related to the prioritization offered by the DHA team. In some cases, there may not be enough information about potential accident scenarios to prioritize certain action items. A staged implementation could be used in this situation, where in some action items are prioritized and implemented while additional information is gathered for the outstanding action items.
Russell A. Ogle, Ph.D., P.E., CSP, CFEI, FAIChE serves as a Principal Engineer and a Practice Director for Exponent.
Brenton L. Cox, Ph.D., P.E., CFEI serves as a Managing Engineer for Exponent.
David C. Hietala, Ph.D. serves as a Senior Associate for Exponent. REFERENCES
1. http://www.actuarialstandardsboard.org/asops/assessment-disclosure- risk-associated-measuring-pension-obligations-determining-pension-plan- contributions-3/
www.ohsonline.com
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■ A consequence, in the context of these hazards, typically Occupational Health & Safety | MAY 2021