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Author(s): Derek Vigstol. Published on November 1, 2017.

In Compliance | NFPA 70E

In the 2018 edition of NFPA 70E, a new tool to assist with arc flash hazard assessment

BY DEREK VIGSTOL

With the publication of the 2018 edition of NFPA 70E®, Electrical Safety in the Workplace®, in October, it is important to understand a significant change related to performing arc flash risk assessments. This concept has undergone a significant transformation over the last few revision cycles, and for the 2018 edition the major change is a new feature, Table 130.5(C), which estimates whether an arc flash event is likely to occur while performing a variety of electrical tasks.

Section 130.5 in NFPA 70E requires that an arc flash risk assessment be performed in order to identify arc flash hazards and estimate the likelihood of an injury occurring. The risk assessment must also determine if additional measures are required to protect workers from any arc flash hazards. Previously, the personal protective equipment (PPE) category method utilized a table to help users determine if PPE was required for a given task, but the table was not applicable to a risk assessment conducted under the incident energy analysis method.

In the new edition of NFPA 70E, that table has been removed and a modified version now exists in 130.5(C), with the intent of providing a better tool for all users, whether they’re applying the incident energy analysis method or the PPE category method to determine the arc flash risk. The biggest change to this table is that it no longer states whether PPE is required, instead listing the likelihood of occurrence of an arc flash event. An estimated likelihood of occurrence of “no” does not mean an arc flash incident will not occur; anyone conducting the arc flash risk assessment must determine if circumstances for their particular situation increase the likelihood of an arc flash incident for the tasks indicated. The 2018 edition includes a new requirement to use a specific hierarchy of risk controls that lists the use of PPE to protect workers from arc flash as the last resort.

As an example of how the new table can be used, consider the task of performing infrared thermographic imaging for routine maintenance or diagnostic measures. To accurately assess this task, it can be broken into two separate tasks: removing covers to expose the internal components, and performing the thermographic imaging. For the first task, the table indicates a likelihood of an arc flash incident occurring, and that additional measures from the hierarchy of risk controls must be used to protect the worker. The table also indicates that, once the covers have been removed, performing infrared thermography outside of the restricted approach boundary does not pose a likelihood of arc flash, and the risk assessment must determine if the unique circumstances warrant additional protective measures.

It is important to note that regardless of the method of conducting a risk assessment, regardless of the task being listed on the new table or the likelihood of an arc-flash occurring, and regardless of the ability to protect an employee from an electrical injury, the primary requirement in NFPA 70E and federal regulations is that equipment be worked on in a verified, de-energized state unless properly justified. Since much of NFPA 70E is based on this philosophical approach to electrical safety, it is especially important to take the time necessary to complete a proper risk assessment procedure. Since no two pieces of equipment or situations are exactly the same, having an absolute answer for every possible scenario is impossible. But this change to the 2018 edition of NFPA 70E emphasizes the importance of performing a solid risk assessment that examines all aspects of the hazards to which employees are exposed, and provides a valuable new tool to determine how best to mitigate the potential danger.

DEREK VIGSTOL is NFPA technical lead of Electrical Tech Services.