Incident Prevention Magazine

6 minutes reading time (1294 words)

What Do We Do About Arc Hazard?

To be absolutely clear – there is an arc hazard in the utility workplace. There is also a need for protecting employees with arc protective clothing. If you are responsible for hazard mediation, you should have an arc protection program or at least a plan to begin a program. Regularly, people call me and ask what they should do about NFPA 70E: Standard for Electrical Safety in the Workplace; and therein lies the problem. NFPA 70E is not the solution to utility arc flash hazards.

What Does NFPA 70E Say?
I have found out that most people who ask about complying with 70E have not thoroughly read it! The scope of 70E in 90.2(B)(5) specifically exempts utilities from compliance with the provisions of the standard. In most cases we are relying on someone else as a “resource” to tell us what 70E says.

Recently, I sat in on an arc protection “training” session at a large industrial line contractor. The facilitator was from a reputable organization and delivered an informative pitch. After the show, I spoke at length with the facilitator. He had been trained by his employer and in fact had never read the NFPA 70E standard.

First Rule: Read the Standard
Once you read it you will learn two things. One is that the arc protection section is only part of the standard. Second, the standard was written to apply to electricians, not utility linemen. The requirements of the standard are in most cases impossible to employ in the overhead workplace, though there is some applicability in underground and substations.

70E requires that the employer establish the arc thermal exposure at the worksite. While that is easy to do in a plant, it is not so easy on a 40-foot pole. Using 70E calculations, you will often find yourself trying to equip linemen for a Category 3 exposure, for a lineman gloving phases outside a substation. That would require overalls and coat with a 25 cal Category 3 hood. By the way, when you turn your head in a hood to look down the span, your hood doesn’t turn with you. That is a problem, not to mention the temperature inside the suit on a 100-degree day. What about communications? See the problems?

What Does OSHA Say about NFPA 70E?
You won’t find a reference to 70E under subpart R, but it is listed in the reference documents in Subpart S. First there are two standards at play – the Apparel standard and the PPE standard. Apparel is not PPE, but PPE can be arc-rated apparel. 70E treats arc-rated apparel as PPE.

On two occasions, OSHA has directly responded to requests about 70E. In October of 2006 OSHA wrote: “Because OSHA has not adopted through rulemaking the requirements of a more recent edition of NFPA 70E, those requirements have not become OSHA standards. A national consensus standard, however, can sometimes be relevant to a general duty clause citation in the sense that the consensus standard may be used as evidence of hazard recognition and the availability of feasible means of abatement.”

In February of 2008 OSHA wrote: “While the NFPA 70E consensus standard has not been adopted as an OSHA standard, it is relevant as evidence that arc flash is a recognized hazard and that PPE is necessary to protect against that hazard. It is clear that the intent of OSHA is that NFPA 70E should be viewed as a mandatory compliance document for the electrical trades under Federal OSHA and by association in State plan enforcement.”

This “back-door” adoption method implies some collateral effect on the line industry even though the first section of 70E provides exceptions to electric utilities, generation facilities and substations. The important thing to remember here is that OSHA did not require compliance with the standard, only that it is evidence a hazard exists. That is usually an indication that OSHA expects employers to have a plan to deal with the hazard.

Historically, as anyone who has had the requisite training knows, OSHA has a preferred hierarchy of employee protection beginning with engineering, then procedures, then PPE. Just as important is that the PPE selected doesn’t create additional hazards. A lineman working in a 25 cal bunker suit cannot move, cannot see, cannot communicate and, even more problematic, is highly likely to suffer a heat-related injury. Those are untenable exposures that will increase the likelihood of an event way above the likelihood of a thermal burn injury.

What is the Right Response?
First, don’t ignore the responsibility to protect your employees beginning with training about the reality of arc hazards and clothes that ignite. If your company doesn’t glove, your program is simple – stay back on the stick. If you glove, including secondary, it’s more difficult. By the way, 70E virtually outlaws energized work.

Next, read the CHSO enforcement guide, Guidelines for the Enforcement of the Apparel Standard, 29 CFR 1910.269(l)(6), of the Electric Power Generation, Transmission, and Distribution Standard. This is the current enforcement policy for OSHA. It isn’t a program in itself, but it does have some good protective guidelines that will inform you and keep you out of trouble with OSHA.

Read the proposed rules from the 2005 rulemaking notices, especially the appendix section on Protection Against Burn Injury. Here you will find very good information for creating an arc protection program that will most likely be in line with the publication of the final rule, whenever that occurs. The proposed rules are reasonably well thought out and much more practical than trying to apply 70E. And yes, under OSHA, cotton is still calculated into the layered ATPV and as a stand-alone garment under certain conditions. Use the NESC as a guide until OSHA completes their current rulemaking.

Prevention: The Key Component
Last, a key component to any arc flash program is to prevent arcs. This is the most practical thing we can do. Procedures before PPE! If you don’t have arcs you don’t have burns. When I am asked to consult with utilities on arc protection strategies, my most frequent concern is the lack of cover setting up the conditions for contact and even more likely a flash. And while we are at it, here’s one of my pet peeves – stop apologizing for asking our linemen to cover up. Every time you say, “I’m not asking you to build a rubber tree,” you are minimizing the importance of cover. 

In underground, the arc hazard is “in a box.” The heat and explosive air expansion that is normally dissipated 360 degrees in air is reflected out of the open side of a cabinet so that persons standing there receive many times more arc pressure than the same size arc in an open space. The work environment here is a lot different than the top of a pole and would benefit from more arc wear under certain operations. The same applies to substations. There is justification for working in padmount equipment and substations wearing arc wear, head and face protection.

Arc protection programs that employ training and good work procedures backed up by reasonable arc protective clothing are an extension of the effective methods that have improved industry safety. Working de-energized helps and that might be law someday. The only other approach we have not done is increase the protective air space between workers and arcs by returning to “sticking” as the only method of energized work.

Now it’s your turn. Do the right thing.

About the Author: Jim Vaughn is a Safety Supervisor with MYR Group’s Sturgeon Electric in the Arizona/New Mexico Line Division. A former lineman with 20 years of transmission and distribution construction and maintenance experience with IOUs and co-ops, he has spent the past 17 years dedicated to safety and training in the line industry.

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Monday, 09 December 2019

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