Question: Can we use metal snaps on shirts for NFPA 70E?  Our traditional shirts have snaps and we are wearing arc rated t-shirts for daily wear then putting on arc rated long sleeved shirts for energized work.
 Answer:  Good question! This opens up how standards work and are often misinterpreted.
 NFPA 70E says 130.6 (D) “Conductive articles of jewelry [...]

One of the things I have pointed out for years but most folks still don’t understand is that shocks (especially high voltage or high amerage shocks) often include an electric arc element.  In the old days, electrical contacts almost always had more burns associated with them than today (Not to minimize shock.  It kills far more [...]

Perhaps the most significant change to the 2009 NFPA 70E is a redefinition of PPE hazard risk categories (HRCs). The principles determining a PPE system for each hazard risk level are now based on developing a clothing system meeting a specific tested cal/cm2 level and comprised completely of arc-rated materials.

The key to this approach is wearing the correct amount of arc-rated protection, not necessarily the exact pieces of clothing listed in the 70E tables. For example, if eight cal/cm2 of protection are required, you can wear an eight cal/cm² arc-rated shirt and pants, or a four cal/cm² arc-rated shirt and pants and a four cal/cm² arc-rated coverall; or an eight cal/cm² arc-rated coverall over cotton shirt and pants. See what we mean? It is the total level of arc-rated protection that matters – that and the absence of synthetic materials. You can wear one level of eight calories or two layers of four calories, or any combination equaling the total cal/cm2 necessary to protect you from severe burns if an arc flash occurs. This method applies to all hazard risk categories. The 25 cal/cm2 required for HRC 3 protection can be achieved by wearing a shirt and pants, coveralls, arc flash suit, or any combination of clothing that meets the required protection level. This change gives employers more leeway in developing a protective clothing system that meets the specific needs of their companies.

If you look at the requirements for HRC 2 in Table 130.7(C) (10), you see the following under clothing requirements:

FR Clothing, Minimum Arc Rating of 8

Arc-rated long-sleeve shirt

Arc-rated pants

Arc-rated coverall

Arc-rated face shield or arc flash suit hood

Arc-rated jacket, parka, or rainwear (as needed) *

Previously the standard required HRC 2 to include an eight cal/cm² shirt or an eight cal/cm² coverall or a 4 cal/cm² with a cotton t-shirt. The cotton t-shirt was mandated. Now, you choose any eight cal/cm² system be it one layer or more but the cotton t-shirt is no longer mandatory and unrated layers do not add to the protection levels in the HRC´s. Natural fiber clothing like cotton, wool and silk are still allowed but cannot add to the protection level because of the risk of ignition. If a company wants to use cotton for protection, they must rate the system with the cotton underneath and control the cotton layer to assure no ignition. This can be done using the ASTM F1959 arc test method.

While this new approach offers more options in choosing PPE clothing, a company cannot randomly choose, for example, a four cal/cm² arc-rated shirt and a four cal/cm² arc-rated t-shirt, deem it an eight cal/cm² system and issue the clothing to electrical workers. When layers are used, the total system must be tested to get the total arc rating. Why? Because the sum does not always equal the whole. Most often, testing proves the system provides greater protection than the sum of its individual parts. However, the opposite may hold true. Some systems protect better than others. Some are barely additive (i.e. 4 cal/cm² + 4 cal/cm² = 8 cal/cm² ) but other systems such as using a heavy layer over a light layer might allow second degree burns at little more than the outer layer´s protective level (i.e. 4 cal/cm² + 8 cal/cm² = 8.1 cal/cm²) but most systems multiply the protection (i.e. 4 cal/cm² + 4 cal/cm² = 20 cal/cm²) See NFPA 70E Standard for Electrical Safety in the Workplace, 2009 Edition, M.3-3.1.

If you want to use an HRC system of layers, you will find many of the larger clothing manufacturers have already tested their arc-rated clothing as a system. Some mixed systems have been tested by utilities and this data is available free of charge from ArcWear.com at ArcWear.com/arctest.

*Additional PPE equipment is also required, such as hard hat and safety glasses, but left out of this list since we are only focusing on clothing.

By Vickie Frost, Hugh Hoagland & Bill Shinn

Vickie, Hugh and Bill are Sr. Partners in eHazard the leading electrical safety and arc flash training company.

Vickie Frost is a technical writer and has been involved in electrical safety for over 20 years.

Hugh Hoagland & Bill Shinn, are members of ASTM F18 and Hugh is taskforce chair of many arc test methods. Bill has over 40 years electrical safety experience and is a Professional Electrical Engineer, retired from Alcoa.

Hugh does most of the world´s electric arc flash testing on clothing and PPE and does regular research at the Kinectrics lab in Toronto. Hugh is owner of ArcWear.com his testing company

They may be contacted at:

e-Hazard.com

13113 Eastpoint Park Blvd.

STE E

Louisville, KY 40223

Office: 502-716-7073

A 2009 change to NFPA 70E

NFPA 70E has long waived the necessity of an energized work permit for such tasks as testing (voltage, current, phasing, infrared and system tuning), circuit identification, and troubleshooting. In 2009, a fourth exemption was added allowing persons to cross the Limited Approach Boundary for visual inspection (130.1(B)(3)).

This newly added exemption allows a qualified person to approach energized equipment for the singular purpose of visually inspecting equipment condition as long as that person does not cross the Restricted Approach Boundary or perform any task. He or she must also wear the appropriate arc flash PPE and follow all required safe work practices.

This eliminates any need for unnecessary paperwork in many areas. Companies may still choose to use a “hot work permit” or an energized electrical permit where conditions indicate. A common example of tasks that may be exempt from permit would be the need to look at a component to obtain a part number, but the most common is infrared inspection of parts for system reliability. Whether an equipment door is opened to verify a component setting, a fuse size or other common work task, a qualified, properly outfitted person may be exempt from a management signature permit for these common tasks under certain conditions.

Anytime such inspections or any work is performed on energized equipment, whether a permit or written approval from management is required or not, persons performing the task must be qualified and must understand the hazards involved. Therefore, the items listed in 130.1(B)(2) must be addressed for all tasks. These items include the equipment and circuits involved in a task; necessary safe work practices; mandatory PPE; the exposed energy sources; knowledge of and proper guarding/marking of the distance of the electrical boundaries (arc flash or shock boundaries); and a job briefing.

Permit required or not, the person who performs such tasks must be fully aware of the increased hazards inherent to energized work and be qualified to work safely around those hazards.

By Vickie Frost, Hugh Hoagland & Bill Shinn

Vickie, Hugh and Bill are Sr. Partners in eHazard the leading electrical safety and arc flash training company.

Vickie Frost is a technical writer and has been involved in electrical safety for over 20 years.

Hugh Hoagland & Bill Shinn, are members of ASTM F18 and Hugh is taskforce chair of many arc test methods. Bill has over 40 years electrical safety experience and is a Professional Electrical Engineer, retired from Alcoa.

Hugh does most of the world´s electric arc flash testing on clothing and PPE and does regular research at the Kinectrics lab in Toronto. Hugh is owner of ArcWear.com his testing company

They may be contacted at:

e-Hazard.com

13113 Eastpoint Park Blvd.

STE E

Louisville, KY 40223

Office: 502-716-7073

www.e-hazard.com

OSHA actually addressed logos for flame resistant clothing related to arc flash in an interpretation letter.  This is interesting. They didn’t give specific guidance but indicated the employer is responsible.
For arc flash issues some use a non-melting thread like Nomex, Kermel or Conex.  Other options are coming online all the time.  I’d bet a modacrylic [...]

This is an excellent site I have used for years for my own medical info BUT I give it a B- on arc flash.  The electrical shock info is up-to-date and accurate but the arc flash has deficiencies.
Click here to visit WebMD’s Electrical Injuries Article.
WebMD says, “Electrical arcs: Current sparks are formed between objects of [...]

This paper by Bill Jordon of Dow Chemical has long been an inspiration to me.  I know others were involved in this work at Dow like Jim Hill and Daleep Mohla but Bill’s paper and influence was recognized a few years back at the IEEE-ESW (IEEE Electrical Safety Workshop).  I had this paper for many [...]

Another in my series of free arc flash training.  These articles address specific issues which come up frequently in e-Hazard.com training on NFPA 70E and CSA Z462 for Electrical Safety in the workplace.
Click Here to read Flame Resistant, FR Clothing Vs. Arc Rated Clothing To Protect from Arc Flash

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Jim Phillips has it right.  One of our first slides in e-Hazard.com Arc Flash and Electrical Safety Training developed in 2004 was a slide on using 2 levels of protection (HRC 2 and HRC 4) before doing the study using the tables for your guide and then doing the study when financing and budget made it [...]

The energized permit requirement in NFPA 70E and CSA Z462 raised hackles in the beginning but if you understand this document you can see it isn’t an arbitrary requirement to make electrical work more administratively difficult.  It is a tool to help control unwarranted live work and ensure only qualified workers performed warranted live work.
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