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 Post subject: Leather Protectors: NFPA 130.7(C)(7) vs. OSHA 1910.137(c)(2
PostPosted: Tue Nov 21, 2017 12:23 am 
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Location: San Jose, CA
Has anyone noticed the difference between NFPA 130.7(C)(7) and Fed OSHA 1910.137(c)(2)(vii), regarding the exceptions for using Leather Protectors, specifically the details regarding Class 0 gloves? Seems like Fed OSHA doesn't require "one class higher" for Class 0 gloves when used without leather protectors, but does require "one class higher" for Classes 1-4. (NFPA70E requires "one class higher" for Classes 0-4). Related snips are below for your comparison.

If you've noticed the contradiction, do you have any idea what the justifications are for these differences? Why did NFPA70E require "one class higher" for Class 0 gloves, or more importantly, why DOESN'T OSHA?

=======================================================

Fed OSHA
1910.137(c)(2)(vii) Protector gloves shall be worn over insulating gloves, except as follows:
1910.137(c)(2)(vii)(A) Protector gloves need not be used with Class 0 gloves, under limited-use conditions, when small equipment and parts manipulation necessitate unusually high finger dexterity.
1910.137(c)(2)(vii)(B) If the voltage does not exceed 250 volts, ac, or 375 volts, dc, protector gloves need not be used with Class 00 gloves, under limited-use conditions, when small equipment and parts manipulation necessitate unusually high finger dexterity.
1910.137(c)(2)(vii)(C) Any other class of glove may be used without protector gloves, under limited-use conditions, when small equipment and parts manipulation necessitate unusually high finger dexterity but only if the employer can demonstrate that the possibility of physical damage to the gloves is small and if the class of glove is one class higher than that required for the voltage involved.
1910.137(c)(2)(vii)(D) Insulating gloves that have been used without protector gloves may not be reused until they have been tested under the provisions of paragraphs (c)(2)(viii) and (c)(2)(ix) of this section.


NFPA 70E 130.7(C)(7)(a)
[...]
Rubber insulating gloves shall be permitted to be used without leather protectors, under the following conditions:
(1) There shall be no activity performed that risks cutting or damaging the glove.
(2) The rubber insulating gloves shall be electrically retested before reuse.
(3) The voltage rating of the rubber insulating gloves shall be reduced by 50 percent for class 00 and by one whole class for classes 0 through 4.


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 Post subject: Re: Leather Protectors: NFPA 130.7(C)(7) vs. OSHA 1910.137(
PostPosted: Tue Nov 21, 2017 4:21 am 
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I forgot the exact edition that they used but it was definitely before the 2008 edition. Let's just say this. NEC 2002 is the first time where arc flash labels became mandatory, the first time that it actually mentioned 70E, and the first time that most organizations actually took serious notice of 70E. The 2000 edition was let's just say honestly not really even usable. Those of us in the field definitely all took notice and we pretty much all had the same attitude. Either 70E had to be fixed to the point where it was actually usable, or the new clause in NEC had to be removed. So what almost all of us did is that we all chose to simply ignore the new rule and wait to see what happened in the NEC 2005 Code cycle as well as the cycle that was ongoing for revising 70E (2004 edition). Lots of "good ideas" show up in code making committees from time to time. They show up and then quite often get deleted on the very next code cycle when it becomes obvious with a wider audience that they are truly bad ideas. Or they get fixed and we move forward.

Because of this elevated notice a huge number of changes went into the 2004 edition that resulted in something that was rough but could actually be implemented. OSHA first started issuing citations in 2006 on a major company, and 2008 fixed a lot of the problems with the 2004 edition. However OSHA's adoption was well before any of this history happened so what you see in Subchapter S is basically an echo of a much earlier version of 70E.

The "one size up" rule for the really thin gloves (00) kind of defeats the purpose. The only reason to use these is for low voltage conditions when manipulating small parts, and putting leather protectors over them kind of defeats the purpose. Taking a step back a minute though let's look at what's really going on at these voltages. The dielectric strength of air is approximately 3,000 V/mm. Leather gloves are a minimum of about 1 mm thick. The cord-and-plug section even recommends wearing clean, dry leather gloves for handling cords and that's the point where it's basically the air in the pores of the leather alone that is responsible for the dielectric strength of leather gloves. So few will admit it but basically gloving up for under around 300 V consists of "avoiding contact" and even though 70E tries to ignore all other forms of shock protection and takes an East coast attitude (it also ignores hot sticks and other methods), you can take a hint here as to how most organizations are handling under 300 V, right or wrong.

That's about as far as I go with rubber gloves. And yes, I use them all the time, particularly when I'm reaching inside a piece of equipment where accidentally brushing up against something is a serious potential danger. I just had them on and off dozens of times yesterday. And I don't do line work.

When it comes to rubber gloves if you use them much at all (as in every day wear), they are not particularly abrasion proof and definitely not puncture proof. If I wore my gloves every day like 70E pushes and didn't wear leather protectors because almost exclusively all my energized work is troubleshooting and I'd be wearing them almost as much as a line worker, there wouldn't be any reason to worry about dates and testing them...I'd be treating them as disposable and probably replacing them in under 6 months. That's why 70E as well as OSHA has all kinds of verbiage about not wearing leather protectors that basically points to "limited use" and strongly encourages doing something else. The recommendations that are out there basically make this a one-time-use thing where you take them out of service and have them cleaned and retested after a SINGLE use without leather protectors.

But here's where my rant is at and where 70E and I differ in interpretation. If you've ever used rubber gloves a lot, particularly for real energized work and not the utter joke that 70E turns it into because they flat out ignore IEEE 516 from where their rules derive from and simply refuse to acknowledge insulated tool work which covers 99% of the low voltage (class 00 and 0) work conditions anyway, you'd probably understand and agree with this sentiment. IEEE 516 has roughly 14 work methods listed but in reality is breaks down to just 4: de-energized work, rubber glove method, insulated tools method, and bare hands method. I'd agree that bare hands has no place below about 69 kV. Insulated tools hold up much longer and you don't need leather protectors for them. Insulated tools method is something as simple as holding your meter probes and taking readings with INSULATED probes that have guards that keep your fingers from slipping off, and insulation to keep the probe tips from causing a fault. There are also almost as many insulated tools as there are normal tools for doing energized work, though that sort of activity realistically doesn't have a place in a utilization environment where the equipment really isn't designed for energized work.

Rubber glove method places the working within the dielectric breakdown distance of air. And it only takes one teeny tiny pinhole in the glove and electricity can and will find that pinhole, and we suddenly have a corpse on our hands, sometimes without warning. That's the whole reason for the hangup with leather protectors, inflators (or a roll test), 6 month inspections, etc. Rubber glove work is just plain dangerous because the worker is constantly in harm's way. The worker IS being shocked, but at such a low level that they usually survive it. Notice that insulated tools by the way have NO voltage rating. They are all either good for 1000 V or 100,000 V per foot. Gloves are nowhere near those ratings. Adding several millimeters to the thickness is simply impractical.

Unlike 70E, I follow IEEE 516. OSHA and 70E both follow IEEE 516. And unlike 70E, OSHA follows what IEEE 516 says. At one time 70E also followed IEEE 516. Every other standard out there for shock protection is based in some way on IEEE 516. I don't understand what the problem is and how come the 70E Committee is so hung up on rubber glove work for everything that they can't get it through their heads. Insulated tool method is hands down one of the safest because it moves the worker outside of the area where dielectric breakdown of air can occur, and insulated tools last MUCH longer. So why insist on the method that is less safe? Someone on the Committee either owns a glove making plant or loves their proctologist or something because it makes no sense.


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 Post subject: Re: Leather Protectors: NFPA 130.7(C)(7) vs. OSHA 1910.137(
PostPosted: Mon Nov 27, 2017 11:39 am 
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ASTM F496-14a Standard Specification for In-Service Care of Insulating Gloves and Sleeves is the guiding document for how to use rubber insulating gloves and sleeves. IEEE 516 is its base and the base of OSHA and NFPA 70E but both attempt to make their rules more practical and offer clarification. NFPA 70E has attempted to clarified the language of OSHA and F496. OSHA does cite ASTM F496 in an appendix and would be primary for abatement issues.

The Class 00 did not exist when OSHA wrote the first version of the safety standard but they did update a bit recently.

OSHA also requires DI testing if used without protectors (this isn't clear from the language). This has been clarified by David Wallis many times at ASTM meetings. This is VERY clear in F496 and NFPA 70E.

The goal in this language is to allow work that MUST be performed energized BUT to make it hard for anyone to use rubber insulating gloves WITHOUT protectors unless absolutely necessary.

I would NEVER count on leather to have any DI protection since it is VERY dependent on tanning process, thickness, leather type and moisture in the glove.

Rubber gloves need protection from abrasion, cut and puncture and from arc flash. We have a proposed standard in process in ASTM to address this with leather and multi-material gloves. Hopefully some day we will have protector gloves that will be thinner but with all the characteristics needed to supplement rubber insulating gloves protection from shock hazards, the primary killer in electrical hazards.

Hugh Hoagland
e-Hazard.com


Last edited by wbd on Mon Nov 27, 2017 2:19 pm, edited 1 time in total.
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 Post subject: Re: Leather Protectors: NFPA 130.7(C)(7) vs. OSHA 1910.137(
PostPosted: Thu Feb 08, 2018 9:24 pm 
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Hi All,
Thank you for your comments with this thread, you have cleared up some misconceptions I had about glove use without the protectors. I went back and was reading F 496 and one of the statements it makes did confuse me. It follows

"F 496 – 08
8.7.4. Rubber insulating gloves that have been used
without protectors shall not be used with protectors until given
an inspection and electrical retest."

Is this saying the insulated glove is OK to keep using without the protector once that has taken place, just not with the protector? My guess would be not to be used until tested with or without the protector but the Standards wording does seem a bit confusing?
Thanks,
Jerry


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 Post subject: Re: Leather Protectors: NFPA 130.7(C)(7) vs. OSHA 1910.137(
PostPosted: Mon Feb 12, 2018 11:03 am 
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This is common confusion with that wording. Some electricians will have TWO pairs of rubber gloves (one for use with protectors and one without). This defeats the intent of the committee and OSHA. Dave Wallis of OSHA has stated to the committee. We DO NOT want people using rubber gloves without protectors BUT because is must happen sometimes, it is allowed. However the electrical test makes it hard to do it so people will not do it unless it is absolutely needed. Looking at the NFPA 70E language on arc flash also makes it hard.

I have tried to upgrade the language in ASTM F496 because of this interpretation but the committee felt it was clear enough asking, "What idiot would think it was OK to use one OVER and OVER?" Thank you for trying to clear this up. I also feel the language is not clear enough.

Hugh Hoagland
hugh@e-hazard.com


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