In a shocking online video last week, a Russian worker repairing a transformer is seen experiencing a potentially fatal Arc Flash.
Carrying out the repairs in an electricity substation, the operative managed to escape with only minor injuries to his arm, however the video lays bare the lack of awareness that surrounds Arc Flash, with the incident simply referred to as an ‘electric shock’. This lack of understanding can leave workers at serious risk of harm, if they are not equipped with sufficient protection against the extreme dangers that an Arc Flash poses.
Here Mark Lant, technical expert at ProGARM, explains exactly what an Arc Flash is, how it differs from an electric shock, and how to protect workers.
What is an Arc Flash?
Most of us in the industry are familiar with an arc – an electric luminous bridge formed in a gap between two electrodes – but its severity and danger is often overlooked. An Arc Flash occurs during a fault, or short circuit condition, which passes through an arc gap. An Arc Flash event can reach temperatures up to four times hotter than the surface of the sun, and can result in devastating results if the correct equipment isn’t being worn – from fatalities to life-changing injuries such as burns and permanent blindness or hearing loss.
Arc Flashes can occur for several reasons, and their frequency is somewhat alarming. From being initiated through accidental contact or equipment that is underrated for the available short circuit current, to contamination or deterioration and corrosion of equipment, these are just a few of the many causes of an arc – making the risks higher than many first think.
While awareness around the dangers of an Arc Flash incident is on the rise, a concerning number of people are still unclear on the hard facts. In fact, according to research conducted by ProGARM and the BSIF, a concerning 63% of professionals across the six sectors most at risk (wind, power generation, industrial electrical, rail, utilities, and petrochemical) aren’t clear on what Governmental guidelines provide guidance on how to work safely when Arc Flash is a threat.
Thought to be the first national research exercise of its type ever conducted into Arc Flash, the research also uncovered an alarmingly high rate of first-hand Arc Flash experience, with 57% admitting they, or someone they work with, has suffered an Arc Flash strike themselves.
What is the difference between an Arc Flash and an electric shock?
There are significant aspects which differentiate an Arc Flash from an electric shock. An electric shock occurs when a person comes into contact with an electrical energy source. Electrical energy then flows through a portion of the body causing a shock, which can result in no injury at all or may result in devastating damage or death.
In contrast, an Arc Flash is when an arcing fault releases dangerous levels of radiant energy, which vaporizes metal that spews from the arc. The air is super-heated causing pressure waves that can throw workers across rooms and create a deadly molten shrapnel. Treatment for stricken workers that survive an incident can require years of skin grafts, hospital stays and rehabilitation. They may never recover sufficiently to regain their lifestyle.
How can you protect workers?
While there is no way to be fully protected from an Arc Flash incident, protective clothing can prevent the most fatal of consequences. If worn correctly, Arc Flash protective clothing and equipment can help to prevent serious injury and fatalities.
However, it’s not just protective outerwear that is needed to ensure protection, as the material worn beneath an Arc Flash protective jacket is just as crucial as outer clothing. While the outer garments are key components for providing protection, they are not enough to match the risk posed to an operative’s safety and effective base layers are needed to defend against the risk of an Arc Flash – everything from Arc Flash underwear to base leggings.
This is because, while the flames caused by an Arc Flash may not actually come into contact with skin through the protective outer layers, the extreme heat from the event can melt the materials used to manufacture everyday undergarments, including nylon, cotton, and polypropylene. This will inflict burns and potentially cause non-Arc Flash protective undergarments to melt into the skin underneath their PPE, potentially causing serious burns.
