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The Risk Assessment Procedure

Sept. 20, 2017
Do you know how to conduct an NFPA 70E-compliant risk assessment?

NFPA 70E, Standard for Electrical Safety in the Workplace, frequently mentions “risk assessment.” But what does this mean, and how do you perform such an assessment? Informative Annex F answers those questions.

The point of risk assessment isn’t to eliminate risk — nor is it to determine what you can get away with safety-wise. The point is to reduce the likelihood of injury (or damage to health) under the circumstances being considered [F.1]. The assessment is an analytic process that follows a prescribed methodology in discrete steps. It’s not guesswork based on what the last job was like.

Before reading the Annex F text, set aside 10 or 15 minutes to carefully study two figures: Figure F.1(a) and Figure F.1(b). They are flow charts for the risk assessment process that show a “simple process” and a “detailed process,” respectively.

Simple process

The simple process flow chart identifies the five major phases of an assessment. For each one, it provides the corresponding reference.

The phases are:

  1. Safety management.
  2. Design control.
  3. Design engineering.
  4. Administrative and behavioral controls.
  5. Communication.

Figure F.1(a) is a guide that references other areas of NFPA 70E (as applicable) rather than just the Annex in which it resides. It also refers to the applicable areas of NFPA 70, National Electrical Code (NEC).

For example, during the design control phase, you determine the “initial estimated risk.” And you refer to the following:

  • NFPA 70E, Sec. 130.4 and Sec. 130.5.
  • NFPA 70, Tables 130.7(C)(15)(A)(a), 130.7(C)(15)(A)(b), and 130.7(C)(15)(B).
  • Informative Annex F.
  • Detailed process

Figure F.1(b) is a flow chart of the detailed risk assessment process. Like the simple process flow chart, it identifies discreet phases. These occur after some preliminary activity, such as collecting the related documents. The phases are followed by evaluation before the assessment may be considered complete.

The phases are, respectively:

  1. Hazard. This phase includes many component steps. It’s mostly analysis to determine such things as the severity of potential injury and the frequency of exposure.
  2. Engineering controls. This phase includes risk reduction measures (based on referenced standards), among other means of mitigation. This phase is followed by an evaluation to see if risk reduction is achieved. If not, you loop back to the beginning. If so, you proceed through the process.
  3. Behavioral controls. This phase includes such things as determining the qualifications of exposed persons and determining what personal protective equipment (PPE) they need. Then you perform an evaluation to determine if the residual risk level is tolerable. If it is, the risk assessment is complete. If it’s not, you loop back to the beginning.

Responsibility

So who is supposed to do all this assessment, and to what degree? It’s not one person. For example, the supplier of electrical switchgear is responsible for the design and construction of the switchgear; and also for information on the operation and maintenance of it. But that doesn’t let the user off the hook. The user is responsible for the operation and maintenance of that switchgear [F1.1].

The details of the risk assessment differ according to role. But the same methodology (see those flow charts) is used, regardless.

Initial. Annex F advises that you carry out an initial risk estimation for each hazard using Figure F.2.4.1. That figure is fairly simple. The main question to answer is, “How likely is someone to get hurt and how badly?” The answer is the basis for the safety measures you’ll take to reduce one or both quantities in that question.

First, consider the severity of the possible injury or health damage. For example, the severity is low if you’re in a control panel but extremely high if the work would put you in the arc blast path of medium-voltage (MV) switchgear serving an industrial plant.

Second, consider the probability that an injury may occur. Figure F.2.1 specifically identifies:

  • Frequency and duration of exposure.
  • Likelihood of an occurrence or event.
  • Likelihood of avoiding or limiting injury or health damage.

Completing the assessment

To complete the risk assessment, you’re going to fill out a table like the example in Table F.2.5 [F.2.2]. It’s at the end of F.2, so you skip over text to get to it. If you don’t have a table like this in your system, create it as a spreadsheet template to use for each risk assessment.

This example table requires some explanation. The last four columns are labeled Se, Fr, Pf, and Av. These are the parameters you will determine the value of. Then you’ll enter the value for each one into the table. But what do these parameters mean, and how do you come up with the correct value?

The answers follow in order:

  • Se: Severity of the possible injury or damage to health [F.2.3]. You assign a numerical score per the instructions in this subsection.
  • Fr: Frequency and duration of exposure [F.2.1]. In addition to some text on how to assign a number, this subsection includes Table F.2.4.1 and that table shows what score to assign if you know how often a duration of more than 10 minutes will occur.
  • Pr: Likelihood a hazardous event will occur [F.2.4.2]. This subsection takes up nearly a whole page, partly because this parameter is often difficult to get right. Once you determine how likely the event is, then you use Table F.2.4.2 to find the corresponding Pr Value. For example, “Very high” gets a 5 but merely “Possible” gets a 3.
  • Av: Likelihood of avoiding or limiting injury or health damage [F.2.4.3]. The explanatory text here is quite helpful. There’s also, as with the other parameters, a table you use to select the correct numerical value.

These last three parameters are part of subsection F.2.4. It tells you to assess Fr, Pr, and Av independently. Then it details each parameter in the text that follows.

Risk reduction

It’s nice to know what the risks are. It’s even better when you know what to do about them. NFPA 70E identifies five protective measures. You don’t want to rely on just one; consider all of them [F.3.1].

For example, using the correct PPE reduces risk. But what if you can redesign the work task to reduce the PPE requirements? A great example of this is installing IR windows for switchgear thermography; this falls under “engineering controls.” The five protective measures are:

  1. Engineering controls [F.3.1.1]. Designing out the danger or at least designing it down.
  2. Awareness devices [F.3.1.2]. Signs, visual alarms, audio alarms, and such are helpful. While they don’t remediate an unsafe condition the way engineering controls do, they can greatly diminish the likelihood of an unsafe act.
  3. Procedures [F.3.1.3]. Procedures don’t take the place of job-specific training, but they are critical to standardizing the work and ensuring it’s methodical. Just having good procedures in itself reduces risk. Adding notes specific to safety amplifies the effect.
  4. Training [F.3.1.4]. It’s expected that the trainer has an in-depth understanding of electrical design. The purpose of the training is so workers understand both the proper and improper interaction with the electrical system.
  5. PPE [F.3.1.5]. There’s only a short paragraph here. Refer to NFPA 70E Sec. 130.7 for a good treatment of the topic.

Risk evaluation

Per the risk assessment process illustrated in Figures F.1(a) and F.1(b), you now go back over the work you just did to see how effective it is and if there’s room for improvement.

The major areas are:

  • Design, elimination or substitution [F4.1].
  • Design, engineering controls [F4.2].
  • Awareness systems [F4.3].
  • Organization and application of a safe system of work [F4.4].
  • PPE [F4.5],

Have you noticed that PPE is the last item in both the remediation and the evaluation of it? That is intentional because PPE is your last line of defense, not your core strategy. First you reduce the risk as much as is practical, then you use PPE to handle the remaining risk. Never use PPE as a substitute for risk reduction.

Verification

The adage “Trust but verify” applies to more than just nuclear arms treaties. In electrical work, there’s a responsibility to ensure the protective measures have been implemented before work begins [F5.1].

That responsibility officially belongs to electrical system designers, constructors, and users [F.1.1]. If you are doing the work, you certainly want to see proof that your protection has been implemented. Focus on how to protect yourself, not on what your listed duties are.

Annex F ends with a sample auditing form [Figure F.5.2], preceded by text saying “…it might be necessary to audit the applicable risk reduction strategy” [F.5.2]. Even if the audit is “unnecessary,” can auditing the risk reduction strategy really be a bad idea?

If you’re just implementing risk assessment, have an outside firm perform the first audit. If you choose an electrical services firm to perform that audit, perhaps they would agree to have you audit their risk reduction strategy as a learning experience for you. Or, they may agree to let you audit theirs in exchange for auditing yours. This could provide a learning experience for both parties.       

Lamendola is an electrical consultant located in Merriam, Kan. He can be reached at [email protected].

About the Author

Mark Lamendola

Mark is an expert in maintenance management, having racked up an impressive track record during his time working in the field. He also has extensive knowledge of, and practical expertise with, the National Electrical Code (NEC). Through his consulting business, he provides articles and training materials on electrical topics, specializing in making difficult subjects easy to understand and focusing on the practical aspects of electrical work.

Prior to starting his own business, Mark served as the Technical Editor on EC&M for six years, worked three years in nuclear maintenance, six years as a contract project engineer/project manager, three years as a systems engineer, and three years in plant maintenance management.

Mark earned an AAS degree from Rock Valley College, a BSEET from Columbia Pacific University, and an MBA from Lake Erie College. He’s also completed several related certifications over the years and even was formerly licensed as a Master Electrician. He is a Senior Member of the IEEE and past Chairman of the Kansas City Chapters of both the IEEE and the IEEE Computer Society. Mark also served as the program director for, a board member of, and webmaster of, the Midwest Chapter of the 7x24 Exchange. He has also held memberships with the following organizations: NETA, NFPA, International Association of Webmasters, and Institute of Certified Professional Managers.

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