The Human Side of Electrical Safety

Understanding human performance modes can impact electrical workplace safety.

By Corey Hannahs, Contributor

It has been said that to err is human. That couldn’t be more true, especially when it comes to electrical safety. As humans, we all make mistakes, but not all mistakes result in getting second chances. An area where we clearly don’t want to make a mistake is around electrical safety. Mistakes involving electricity might not come with a second chance. To truly be safe while performing electrical work, we need to fully understand the mistakes that humans can make and try everything we can to minimize them.

Informative Annex Q in NFPA 70E®, Standard for Electrical Safety in the Workplace®, is a great resource for human performance and how it can impact electrical workplace safety. Even though it isn’t an enforceable part of NFPA 70E, a portion of what Annex Q provides is usable information for employers around the typical modes that humans perform in and the associated errors that come along with those modes. Analyzing the modes in which employees perform and make decisions based on their specific job duties, will help employers create an Electrical Safety Plan (ESP) that helps to eliminate risk to their employees. Annex Q addresses three different types of human performance modes: rule-based, knowledge-based and skill-based.


Rule-based human performance mode is when the work situation is likely to be one that the employee has encountered before, has been trained to deal with, or is covered by a specific, established procedure. It is called the rule-based mode because the individual applies memorized, or written, rules. These rules may have been learned as a result of interaction at the workplace, through formal training, or by working with more experienced workers. In rules-based mode, employees typically follow “if-then” logic. The employee looks at the signs and symptoms overall within the situation, analyzes them against their stored knowledge, and then typically reacts in a predictable manner.


Knowledge-based human performance mode is when an employee is working with uncertainty about what to do; no skill or rule is readily identifiable. The individual relies on his/her understanding and knowledge of the situation in order to try and develop an appropriate response.

The uncertainty the employee is feeling creates a need for information, which consumes their thoughts and focus. Thinking takes more effort and energy, and therefore the time devoted to processing the information to select an appropriate response can be considerable. Clearly this compounds the pressure an employee may already be feeling, if the task at hand is already in a “this needs to happen now” mentality, such as a production line being deenergized due to failure.


Skill-based human performance mode is quite different than knowledge-based mode when it comes to the time it takes to process information. Where it can take minutes to hours to process information in knowledge-based mode, skill-based decisions can happen in milliseconds. In skill-based mode a person is often executing a task that involves actions that they have done before and are very familiar with, such as turning on a circuit breaker.

Although it is a skill-based decision that they have made before in a common situation, that does not necessarily mean that it is being done as safely as possible. It could simply be a skill that has been learned the wrong way. Looking back on my own career, I can tell you that there are things I have done in the rearview mirror that I know were not done safely, but I was taught how to do it by a superior who, at the time had not been trained how to approach safety correctly. It was just a mentality of “this is how we do it because this is the way we have always done it.” I share this to make you aware of what happens every day on jobsites all over the world, so you know what we are up against and what needs to change when it comes to electrical safety.


Because rule-based human performance mode requires interpretation using an “if-then” logic, misinterpretation is the most common error made. Errors often involve deviating from an approved procedure, applying the wrong response to a work situation, or applying the correct procedure to the wrong situation.

Knowledge-based errors are common where the employee does not properly evaluate the work situation and tasks at hand. To make the appropriate decision here, employees must both properly diagnose the situation and then problem solve based on the information they have available to them.

In general, humans don’t usually perform at their best in high-stress, unfamiliar situations where they are required to “think on their feet” in the absence of established rules, routines, and procedures to handle the situation. The tendency is to use only information that is readily available to evaluate the situation and become focused on one aspect of the problem to the exclusion of all other considerations. This is where it becomes imperative that employer ESPs establish policies and procedures for common tasks up-front, so employees aren’t left to make poor decisions based on incomplete or inaccurate information that they come to on their own, as opposed to already having procedures in place within the employer’s ESP.

For skill-based human performance mode, there are two common errors that may occur, the first being the inattention to critical details. Omitting key parts of the process, such as wearing PPE appropriate to the task at hand, is one example. It could be as simple as an employee wearing the appropriately rated Category 2 PPE to service one piece of electrical equipment only to move across the room to begin servicing another piece of equipment that requires Category 3 PPE, and not paying attention to the changing need in those specific work conditions.

The second common skill-based human error is having a perceived reduction in risk. As an employee performs a task repetitively, they are likely to be more comfortable with how it is performed, in turn taking for granted evaluating the risks associated with  performing the task in that specific moment. Because they may have performed the same task on that piece of equipment before and are comfortable doing it the way they did it previously, maybe they don’t notice an additional risk presented this time around because a critical cover is now missing from the equipment.


Our reality is that we are all human, made of flesh and blood, and capable of making an error at any given time. Therefore, we must be proactive in expanding our knowledge and actions around safe electrical work practices to ensure that when mistakes are made, they are manageable and not catastrophic. Openly communicating what went wrong and working together to change processes and habits to prevent the same mistake happening again is a significant step in the right direction.

Whatever role we play in overall electrical safety in the workplace, we must first look at ourselves and determine our shortcomings, then focus on how best we can improve to do our part in minimizing electrical incidents in the workplace due to human error.

Electricity will provide very few trials, if any, before it returns an error that can have a significant negative impact on the life of a worker, his/her family, and their employer.

In closing, I ask: “what can you do today to improve upon electrical safety in your workplace?”

To hear an audio version of this article, check out the NFPA Podcast Code Corner segment from the “Why Electrical Safety Matters” episode. Also be sure to view the associated NFPA Electrical Safety Month webinar with arc flash survivor, Jason Brozen, to learn about one man’s journey of survival after a near death experience on the job.

Corey Hannahs is a Senior Electrical Content Specialist at the National Fire Protection Association (NFPA). In his current role, he serves as an electrical subject matter expert in the development of products and services that support NFPA documents and stakeholders. Corey is a third-generation electrician, holding licenses as a master electrician, contractor, inspector, and plan reviewer in the state of Michigan. Having held roles as an installer, owner, and executive previously, he has also provided electrical apprenticeship instruction for over 15 years. Corey was twice appointed to the State of Michigan’s Electrical Administrative Board by former Governor Rick Snyder, and he received United States Special Congressional Recognition for founding the B.O.P. (Building Opportunities for People) Program, which teaches construction skills to homeless and underprivileged individuals.

Notice: Any opinion expressed in this column is the personal opinion of the author and does not necessarily represent the official position of NFPA or its Technical Committees. In addition, this piece is neither intended, nor should it be relied upon, to provide professional consultation or services.

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