Arc Week Season 2, Ep. 1: Shark-Rated vs. Arc-Rated – Matching PPE to the Hazard

Tyndale presents Arc Week: a unique, week-long educational look at the world of arc flash hazards through the lens of Shark Week. Join Scott Margolin – our dedicated technical expert by day and passionate shark enthusiast in his free time – for engaging, memorable parallels that bring important lessons about risk protection and PPE to life.
Catch it all: Season 1,
Season 2, Season 3.

In this episode, we’re taking a deep dive on personal protective equipment (PPE): Do I need it? When? What PPE do I need, and how do I match it to the hazard?

Believe it or not, swimming with sharks can tell us a lot about PPE for working with arcs and how it correlates to your environment. You wouldn’t swim with a great white shark without a cage, and “swimming” with arcs is much the same. In both situations, it’s critical to match the PPE to the hazard assessment. Vice President of Technical, Scott Margolin explains, drawing parallels from different types of shark dives:


It all starts with hazard analysis.

You might think that all electrical work and all shark dives require PPE, but if you’re familiar with the hierarchy of control, you know that PPE is the last line of defense when it comes to industrial safety.

And shark diving is similar, if less formal: hazard analysis always comes first.

When diving with sharks we need gear to see, to breathe, and to protect our skin from environmental hazards. We consider:

  • The species we expect to encounter – their size and numbers,
  • The location and depth of the dive,
  • Other environmental factors, like time of day, water clarity, and the presence of other factors like prey species or current.

From there, we use this “dive profile” to identify the right PPE. Lower hazard levels require less PPE, while higher hazard levels require more PPE. The vast majority of shark dives can be completed safely with this approach.

Arcs are like sharks. We identify a larger hazard and increase PPE accordingly:


PPE Category (CAT)

Diving with Sharks

“Swimming” with Arcs

Hazard Profile

PPE System

Assessed Incident Potential

PPE System


Dive with Small, Docile Sharks

Mask, Breathing Apparatus, Rash Guard

<4 cal/cm2

Shirt/pant or coveralls with 4 cal or greater rating, other PPE


More or Larger Sharks + Complex Dive Conditions

Wetsuit, Gloves, Short Shark Bully to Gently Guide Shark Away

<8 cal/cm2

Shirt/pant or coveralls with 8 cal or greater rating, other PPE


Feeding Dive – Drawing Sharks, Which are Competitive Eaters, Close Enough to Hand Feed

Chainmail gloves, sleeves, or full bodysuit; hockey helmet; safety diver to cover feeder’s blind spots

<25 cal/cm2

Cat 3 arc suit


Great White Encounter

Shark cage instead of chain mail

<40 cal/cm2

Cat 4 arc flash suit


And luckily, with arc flash:

  • We can be precise with hazard analysis – quantifying it with incident energy calculations. Plus,
  • We can also measure the protection provided by the PPE (arc ratings).

Combine the two, and we can make sure the protection meets or exceeds the potential hazard – dramatically reducing injury and saving lives.

Learn more about NFPA 70E, your lifeguard in arc-infested work zones, which defines the four levels (known as PPE Categories or CATs, formerly known as Hazard Risk Category or HRC) of arc protection and helps guide you to the right level of PPE for the task at hand.

Need to layer AR garments to ensure your clothing system exceeds the incident energy potential? It’s not as simple as adding the arc ratings together. But don’t worry: we’ve made it easy – check out Episode 2 for more information, and download our mobile app today.

Do you have a flash fire – rather than an arc flash – hazard? We’ve got you covered, too. Whereas NFPA 70E specifies protection on the industrial electrical side, NFPA® 2112 (provides performance specifications for FR fabrics) and NFPA® 2113 (provides guidance on garment selection, care, and use) are the “lifeguards” for your hazard. Learn more about “the manikin test,” pass/fail testing requirements, and other key tests in NFPA 2112, and take a deep dive on the important difference between mere compliance and true protection from flash fire hazards.

Check out Episode 2: Hidden Dangers for three things to know about layering for hazards above CAT 2 (incident energy potential 8-20 cal/cm2).  And follow along with Season 2 for a “deeper dive” on CAT 3 and CAT 4 PPE, plus arc history and behavioral and situational aspects of arc flash safety – culminating in a real shark dive to show it’s possible to do dangerous tasks safely with the appropriate hierarchy of controls.


Series: Arc Week

What do sharks and electric arcs have in common? Watch the full series to find out. In each episode you’ll find engaging, memorable parallels that bring important lessons about risk protection and PPE to life. Visit each season’s hub to catch it all:

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