It is good to hear that this blog is getting those involved with electrical safety to think and talk about what they are doing to protect employees from electrical injury. I have been asked to explain what it means to use the hierarchy of risk controls regardless of a policy requiring the establishment of an electrically safe work condition (ESWC) or permitting justified energized work. How to use the hierarchy is obvious when it comes to justified energized work. However, using the hierarchy when establishing an ESWC is less obvious to many. It should be used the same way regardless of your policy. This comes down to considering the act of establishing an ESWC to be an administrative control to achieve elimination of the hazard. Bear with me and hopefully this will again shed some light on the process. Remember that the act of establishing an ESWC is considered to be energized work.
Consider an electrical installation with a step-up transformer (480/2400 volts) being used for a motor installation. An interrupting switch for a motor load is on the secondary. The primary disconnect and overcurrent device is located back at the switchgear. The incident energy at the transformer input terminal is 22 cal/cm2 with an arc-flash boundary out at 12 feet. Your employee will don 25 cal/cm2 PPE. This will require a full hood and arc-rated gloves. She will complete the eight steps in 120.5. She interrupts the motor circuit then opens the breaker in the switchgear. She goes into the transformer enclosure to verify the absence of voltage. The limited approach boundary is at 5 feet because the secondary is exposed. She is within the restricted approach boundary (2 feet, 2 inches) of the secondary terminals which requires the use of insulated tools and shock PPE rated for 2,400 volts. She will have established an ESWC while being potentially subjected to 2,400 volts and 22 cal/cm2.
If the hierarchy of risk controls was used, here is what the scenario might have been when establishing this EWSC. The overcurrent device is replaced with a current-limiting device with a faster clearing time to lower the incident energy to 8 cal/cm2. The arc-flash boundary has been lowered to 5 feet. There is a viewing window in the motor disconnect to permit visual verification that the load has been isolated. (Yes, this not the disconnect device but it is still used here.) The switchgear is arc-rated so that if an incident occurs when opening the breaker the arc-flash will be directed away from the employee. The input terminals of the transformer are in a separate enclosure allowing the use of shock PPE rated for 480 volts. The limited approach boundary is now at 3 feet 6 inches and the restricted approach boundary is 1 foot. The employee dons 10 cal/cm2 PPE with leather glove protectors and a face shield. She will complete the eight steps of 120.5. She verifies that the contacts isolating the motor load are clear. She opens the breaker in the switchgear then opens the transformer terminal box to verify the absence of voltage. She has also established an ESWC while potentially being subjected to 480 volts and 8 cal/cm2. Other methods might have been used to mitigate the hazard. The point is the hierarchy of risk controls was used to increase safety for the employee rather than solely establishing an ESWC.
Your employee can be injured at 480 volts and 8 cal/cm2 just as she can be injured at 2,400 volts and 22 cal/cm2. However, there is less risk and lower hazard levels in the second scenario. This is why you must consider the hierarchy even when your policy is to establish an ESWC. You may decide not to use some or all other controls but your risk assessment should consider them. There should never be energy present and the voltage measured should always be zero when an ESWC is being properly established. Your employee should truly never be exposed to an electrical hazard.
So why go through these additional steps? I am aware of situations where equipment is labeled with an incident energy higher than what currently available PPE is rated to provide protection from. The apparent “theory” is that since the policy is to eliminate the hazard through an ESWC that the hierarchy need not be used to lower the risk or hazard. Using and wearing inadequately rated PPE might be considered by many to be as irresponsible as not using any PPE. The personal protection your employee is required to use is for no other reason than something unexpected might happen that could injure them. When that does happen isn’t it important to provide, if not at least consider, a higher level of protection for that employee?
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For more information on NFPA 70E, Standard for Electrical Safety in the Workplace, read my entire NFPA 70E blog series on Xchange
Next time: NFPA 70E First Draft Meeting
An important issue has arisen with NFPA 70E®, Standard for Electrical Safety in the Workplace® and what it takes to establish an electrically safe work condition (ESWC). There have been some misinterpretations of the content. The issue revolves around the hierarchy of risk controls, the act of establishing an ESWC and a properly established EWSC. The words are carefully chosen and it is troubling that they are being misunderstood. If I have made an error in my presentations, in NFPA 70E®, Handbook for Electrical Safety in the Workplace® or in this blog that a properly established ESWC has not removed the hazard, I apologize for that. However, I am not aware of any instance where this has occurred and would gladly welcome any feedback. The following statements from those forums agree with industry’s view that a properly established ESWC has removed the hazard:
How you look at the hierarchy is a safety issue. If you believe the act of establishing an ESWC is an elimination control there would be no need to exhaust time or money in an attempt to use substitution, engineering, awareness, administrative or PPE as a control function since the hazard has been eliminated. Step 1: ESWC. Done. However, I don’t see it that way since the act of establishing an ESWC and a properly established ESWC are two separate concepts. The act of establishing an ESWC relies on awareness, administrative, and PPE controls to achieve elimination. The hazard is not suddenly eliminated. An ESWC does not exist until all eight steps of 120.5 have been completed. With electrical safety do not treat this as a trivial matter. What seems to be misunderstood is the applicability of the required hierarchy of risk controls. The following statements help clarify the issue:
There is a safety concern which clearly indicates that the hazard is not eliminated during the act of establishing an ESWC. Additional statements regarding this follow:
The chosen words convey the fact that the act of establishing an ESWC is not elimination of the hazard. The act of establishing an ESWC relies on awareness, administrative, and PPE controls not on elimination. These are numbers four (4), five (5) and six (6) on the hierarchy. Once the EWSC has been properly established, elimination of the hazard has been achieved. Equipment in an ESWC has had the hazards removed. The chosen words consistently convey this fact.
The fact is that the primary work procedure must be to establish an EWSC. Consider what the employee must do before they are permitted to remove their PPE (time when the hazard has been eliminated). If the act of establishing an ESWC was elimination of the hazard, there would be no need for an energized work permit, training, safe work procedures, or the donning of PPE. It is often difficult to see things differently than what is currently considered. In my mind, the act of establishing an ESWC was an elimination control until this specific hierarchy of risk controls became a requirement. The hierarchy has helped clarify the difference between the act of establishing and a properly established EWSC.
This should help clarify the difference between the risk control of elimination and the risk controls of awareness, administrative, and PPE necessary to establish an ESWC. It is equally important for safety to make a distinction between the act of establishing an ESWC and the result of a properly established ESWC. When you think of them as the separate issues that they are, it allows the hierarchy to be implemented to increase electrical safety. This should clarify my position on the issue of an electrically safe work condition. I am not aware that any of my statements are incorrect based on the requirements in NFPA 70E. Please quote me correctly. This is not semantics. This is employee safety.
For more information on 70E, read my entire 70E blog series on Xchange.
Next time: Outsourcing your risk assessments.
With so much emphasis on the need for a qualified person in NFPA 70E®, Standard for Electrical Safety in the Workplace® many wonder why 110.2(A)(2) is a requirement. The title of NFPA 70E provides the answer. There is a potential for injury anytime an employee is interacting with electrical equipment, not just when they are working on electrical equipment. Examples of a person interacting with electrical equipment include a janitor opening a panel to turn on lights in the facility at the start of the day or a machine operator starting the equipment and performing his/her duties. Both must be trained in safety-related practices related to these tasks. Equipment must be under normal operating conditions before operating this equipment is considered to be “safe”. All employees should be trained to understand the normal operating conditions for the equipment they are interacting with. Without that understanding they could be put a risk of an electrical injury. Beyond that there are many general electrical safety topics that any employee should know.
Employees not required to be a qualified person by NFPA 70E must have the knowledge and skills necessary for their safety when interacting with electrical equipment. After understanding normal operating conditions for the equipment, the additional training is often common sense with regard to electrical safety. You may have employees using extension cords and portable equipment for example and they should trained in the use of such equipment. The following is a sampling of some basic, commonsense rules for avoiding electrical accidents and injuries that unqualified employees need to understand:
You must determine the subject matter that your unqualified employees must know. In order to do so you must understand the duties they perform in the course of their day. Not all unqualified employees will need the same training and some employees may require a focused training program. Training will vary to deal with the specific equipment they interact with. There is nothing prohibiting comprehensive training for all employees. None of this training will make the employee qualified under NFPA 70E requirements but this training will affect electrical safety in your workplace.
For more information on 70E, read my entire 70E blog series on Xchange.