January 26, 2016 | Frank MacDonald |

Rubber Insulators: The Things You Need to Know

Rubber Insulators Arc Flash Ratings

For those who need a refresher about what arc flashes are and the kind of risks involved when they occur, in one of our previous blog articles, we mentioned that arc flashes happen,

“when an electrical current jumps from the desired electrical path and travels through the air from one conductor to another conductor. When this happens, anyone who might be in the vicinity or in the path of the discharge can be severely injured – or in some cases, even killed.”

For this reason, those who work in applications where arc flashes can occur should be wearing properly tested, arc-rated gloves with rubber insulators underneath.

“What are the rubber insulators for?” you might be asking.

Well, in a nutshell, rubber doesn’t conduct electricity. That’s why when you’re looking for reliable hand protection against shocks – which usually goes hand-in-hand with arc flashes – we recommend that you wear rubber insulators inside of your arc-rated gloves. That’s because rubber is a natural insulator – so, unlike other materials that act as conductors, it’ll stop the electric currents from travelling through your skin and electrocuting you. It’s an easy fix to a major problem.

…That is, unless the rubber insulator catches on fire. Well, that’s a whole other can of worms.

When asked the question “Can rubber insulating gloves ignite in an arc flash?” during the webinar we recently hosted, Hugh Hoagland — an arc flash expert — provided this helpful answer:

“That’s for sure – [rubber insulators] can [ignite]. We actually rate them. In the test method, we require an ignition probability of anything that won’t pass a vertical flame test and rubber insulating gloves – or leather gloves – don’t pass the vertical flame test. They will continue to burn or they will get longer than a six inch char. So, we actually do arc rate them for their ignition value. You can’t ignite – or at least I haven’t ignited – a leather glove in an arc flash, but because it’s an impinged flame, it just chars the outside and puts itself out. In a vertical flame you can ignite a leather glove and a rubber glove, so when we get people who want to test them, we give them a probable ignition because yes, they can ignite, but it’s fairly rare. Typically, the arc flash is on the hands and covered by a leather protector, so the leather protector typically protects the rubber insulating glove, but they can ignite, for sure.”

Well that’s pretty frightening, now, isn’t it? We thought so too. That’s why the best thing you can do in order to protect your hands from the aftermath of arc flashes is wearing arc-rated, flame-resistant gloves over top of your rubber insulators. And, as Hugh mentioned, since you know that flame is a very real issue in the event of an arc flash, look specifically for rubber insulators that have been properly tested and arc rated for their ignition value.

That way you’ll be protected from both the dangerous risk of electric shock as well as from the threat of burns. We don’t want lightning to strike twice.

Looking for a reliable pair of work gloves that are both arc-flash rated and flame-resistant?

These high-visibility Clutch Gear® mechanics gloves offer those features, and so much more:


Interested in a free sample for your workers? Click the orange button:


From all of us at Superior Glove to all of you: have a safe day!
For more information on Arc Flash, view our “Guide to Understanding Arc Flash” infographic!

Frank MacDonald
About Frank MacDonald