What You Need to Know to Protect Workers from an Arc Flash Hazard

| May 24, 2017

What happens when an electrical lineman is working on a transformer from the bucket truck and accidentally drops a tool that results in what would otherwise be thought of as a simple spark?

It could easily trigger a dangerous release of energy known as an arc flash (aka arc fault and arc blast). This release of energy, created when electrical current leaves its intended path and travels from one conductor to another, or from one conductor to the ground, can have serious—sometimes tragic—consequences.

Arc flashes are incredibly dangerous, capable of producing a reaction strong enough to knock a person down, propel an object through the air, melt metal, and rival the blast decibel of a gunshot. Unfortunately, it can also cause serious burns, injury or even death.

According to the Occupational Safety and Health Administration (OSHA), arc flash burns are one of the top three most common hazards when working with energized electrical equipment.

In fact, every day in the U.S. there are up to 10 arc flash incidents, totaling more than 3,600 disabling electrical contact injuries each year. Even more frightening? The violent nature of arc flash exposure, which can result in a fatality, even if a worker is 10 feet from the blast site.

So what should you do keep workers safe from arc flash hazards?

Avoiding Arc Flash Tragedies

  1. Determine hazard potential. Unsafe work environments, including dust, dropping tools, accidental touching, condensation, material failure, corrosion and faulty installation, can cause arc flash hazards. Conduct an arc flash hazards audit, looking for situations in which workers can be on or near exposed and energized equipment, or in a hazardous environment. Collect detailed data and information, such as transformer nameplates, conductor sizes and circuit breaker settings, and then create a current one-line electrical drawing. When determining which data to collect, refer to National Fire Protection Agency (NFPA) 70E requirements for safe workplace practices.
  2. Reduce exposure.  Ask a licensed professional engineer with a thorough working knowledge of NFPA 70E requirements to identify ways to reduce or eliminate potential arc flash hazards, such as de-energizing equipment; preventing or limiting worker access with insulating, guarding or barricades; and tagging equipment with NFPA-compliant arc flash hazard and electrical shock warning labels.
  3. Calculate arc flash boundary. Work with the licensed professional engineer to determine the minimum required, safe working distance from each piece of equipment for which an arc flash hazard exists. Use a reliable source or methodology, such as NFPA 70E tables or formulas, IEEE Standard 1584 formulas or spreadsheet calculator, or boundary calculations software.
  4. Protect employees. To complement existing worker safety training programs, MSA The Safety Company provides Fall Protection Competent Person training and reminds employers that they are required to estimate incident heat energy of arc hazards to which workers could be exposed. In addition, employers must provide at-risk workers with PPE that has an arc rating greater than or equal to the estimated heat energy.

    To assist employers in ensuing that workers exposed to electric arc hazards do not wear clothing that can melt onto skin or ignite and burn when exposed to arc flash, as well as to mitigate the physical impact of arc flash, MSA recommends the following AF (arc flash)-rated PPE, which meets OSHA 1910.269(L)(8) as well as ASTM F887 arc flash requirements.

    Head, Face & Eye Protection

    AF-rated eye/face protection products, including faceshields, safety spectacles and goggles, must be worn by at-risk workers. Such PPE must resist high heat and maintain necessary structural integrity in the face of arc flash hazards. Look for the arc flash system to ensure your selection of AF-rated protection. MSA offers a complete line of AF-rated PPE head, face and eye protection, including V-Gard® 500 Vented Protective Cap and V-Gard® Arc Visors.

    Personal Fall Protection

    AF-rated, full-body harnesses, such as MSA’s premium EVOTECH® Arc Flash, are built to withstand an arc flash impact and perform as required in the event of a fall.

    To ensure the worker is properly connected at height in which arc flash hazards are present the MSA Latchways® Arc Flash Personal Fall Limiter (PFL) provides lightweight, energy-absorbing protection. As the most compact AF-rated lifeline in its class, the self-retracting Latchways Arc Flash PFL is built with a lifeline made of aramid fibers with flame resistant properties.

The bottom line is this: Arc flash accidents happen on utility job sites and within industrial and other facilities where arc flash hazards exist. Arc flash-rated head, eye, face and fall protection products are the smartest course of action and, in many cases, are now required for at-risk workers.

Arc flash hazards are serious, so the best thing to do is to safeguard workers from the potential for a full-blown tragedy. For more information or to schedule a free safety evaluation, please visit MSAsafety.com, keyword: arc flash, or call 800-672-2222.

MSA Safety

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Category: Industry News