Arc blast dangers can be minimized with a Hierarchy Of Controls. Hear the difference between arc flash and arc blast, plus the five methods to prevent them.
The surface of the sun is cooler than an arc blast. This explosive electrical hazard can easily kill and injure. In this podcast we present the Hierarchy Of Controls to prevent arc blast: Elimination/Substitution; Engineering Controls; Administrative Controls; Work Practice Controls Personal Protective Equipment.
The hearing protection requirement for arc blast in NFPA 70E 2015 is also reviewed. Stay safe with electricity!
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Dan Clark: If you work around electricity you know arc flash: A sudden fault, a spark jumps through the air.
Even worse is an arc blast — an arc flash on steroids. Let’s prevent it with an Arc Blast Hierarchy Of Controls, next.
Hi, I’m Dan Clark with The Safety Brief. We take on health and safety hazards in today’s demanding industrial and construction worksites, a service of Creative Safety Supply. Save 10 percent off your entire order at creativesafetysupply.com with coupon code BIG10.
Arc blast. How does it happen?
First let’s look at arc flash. Electric current leaps through the air between conductors. This happens due to faulty wiring, moisture, bad insulation, dust or corrosion.
Things can get hot. Really hot. Three times hotter than the sun, 35,000°F. Now, this alone can cause severe burns and other life-threatening injuries. But now it gets serious.
That arc flash caused a rapid expansion of air. Metal and other materials at that temperature boil, vaporize and expand. So all of this expansion creates a pressure wave that:
— Can throw people at 100 miles an hour.
— Can cause lung damage.
— Can cause hearing damage.
— Can toss shrapnel at more than 700 miles an hour.
To prevent these hazards let’s look at the Arc Blast Hierarchy Of Controls. There are five.
1. Elimination/Substitution. Working on energized equipment should be the EXCEPTION not the RULE. Schedule jobs so power sources can be de-energized, grounded and tested. Outdated or worn electrical equipment should be replaced with a newer, safer model.
2. Engineering Controls. Set up barriers around hazardous locations. Locked electrical vaults and high fences around transformers are examples.
3. Administrative Controls. Start a lockout/tagout program, complete with training and equipment. It must be accepted and practiced by both managers and workers.
4. Work Practice Controls. Workers must have the knowledge, training and education to do the job. Management sets expectations for safe work practices. Workers meet or exceed safety rules and best work practices with no shortcuts.
5. Personal Protective Equipment: PPE. For arc hazards, the company must provide FR clothing with an arc rating greater than or equal to the estimated heat energy of any electrical arc hazard a worker is exposed to.
An arc blast can be louder than sticking your head in a jet engine — 140 dB. Wear ear plugs that fit properly. Earmuffs do not meet the standard. This is specified by NFPA 70E 2015.
Remember PPE is the last line of defense. The other four Hierarchy Of Controls should be fully implemented first.
That’s all for this episode, Arc Blast Hierarchy Of Controls. Join me again for more ways to stay safety compliant in today’s always-changing landscape of safety requirements. I’m Dan Clark of The Safety Brief, a service of Creative Safety Supply. Save 10 percent off your entire order at creativesafetysupply.com with coupon code BIG10.
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