06164466 Nfpa f0e and Arc Flash Ppe Update

7/27/2019 06164466 Nfpa f0e and Arc Flash Ppe Update

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NFPA 70E AND ARC FLASH PPE UPDATE

Copyright Material IEEEPaper No. ESW2010-21

Elihu Hugh Hoagland IV

Member, IEEEArcWear.com/e-Hazard.com/ArcStore.com

13113 Eastpoint Park Blvd. STE ELouisville, KY 40223

[email protected]

Abstract PPE in the electric arc has been evolving since theearly 1990s. With the introduction of OSHA Safety and HealthStandards in the US and arc test methods in ASTMInternational, the growth of knowledge in PPE and proliferationof PPE for electric arc has grown throughout the world. In 1995,NFPA 70E began addressing arc flash boundaries and NESCadded safety requirements for electrical safety.Misunderstandings and errors in marketing still abound butknowledgeable users, manufacturers and researchers havehelped make materials more comfortable, protective andavailable for many more work situations. OSHA 1910.269 in1994, NESC in 2007, NFPA 70E in 2000, 2004 and 2009 andnow CSA Z462 have codified clothing for electric arc. Brazil,Peru, Russia, recently South Africa, New Zealand, and Australiaare codifying laws related to arc flash PPE so the internationalfocus is critical.

Index Terms NFPA 70E, ASTM, NESC, electrical safety, arcflash training, arc flash, arc blast, PPE, personal protectiveequipment, IEEE, incident energy, ATPV, arc thermalperformance value, energy breakopen threshold, EBT, arc flash

hood, arc flash suit, arc rated rainwear, hairnets, beardnets, arcrated bras, arc rated underwear, balaclava, sock hood.

I. INTRODUCTION

Arc ratings are critical to proper PPE. Some flame resistancestandards, even international standards, are inadequate toprotect workers in electric arc exposures. Basic principles forproper arc clothing and some practical principles for choosingand using arc flash PPE will be discussed.

II. SYSTEMCHOICE

A. Standards for Arc Rated Materials

Materials which may be used in electric arc must meet criticalstandards. Most of the arc flash PPE research is occurring inCanada, the US and Germany though countries all over theworld are developing and testing products.

1) Clothing - Clothing materials must meet ASTM F1506, orIEC 61482-2:2009 which assures basic flame resistanceand assigns an arc rating to the fabric. Fabrics claimingflame resistance but which do NOT meet either of thesestandards are often treated melting fabrics and have noplace in most flame situations. Many FR-treated acrylics

claim to be flame resistant and offer wording like will notsustain flames under high heat conditions These typesof materials are dangerous in electric arcs. They willmelt in an electric arc or in a flash fire. They cannot pointto a real standard they actually meet. Often themanufacturers cite ASTM D6413, which is only a testmethod with NO pass/fail criteria, or they cite NFPA 701,which is a curtain standard and NOT a clothing standardor some cite the 1981 FTMS (Federal Test MethodStandard) 191A-5903 or 191A-5901 which have been outof print since the 1980s.. Other material manufacturerscite ASTM F1358 Standard Test Method for Effects ofFlame Impingement on MaterialsUsed in Protective Clothing Not Designated Primarily forFlame Resistance. As the title implies, this is NOT aflame resistance standard. It is really only useful ongarments thatcould be exposed to a small flame such asa surgical garment. Picking the proper standard forclothing specification is critical.

2) Rainwear Rainwear was one of the first applicationsidentified that didnt have an arc flash answer. The

ASTM F18 Committee began work on a rainwearstandard in the early 1990s. The resulting F1891standard is now the only international standard specifyingwhich flame resistant rainwear is useful for electric arcprotection. NFPA 2112 for flash fire also cites rainwearbut the most commonly cited is ASTM F1891. TheF1891 standard is basically the same arc requirementsas F1506 but with a requirement to test for EBT on allrainwear fabrics. This is expressed as an EBTAS(Energy Breakopen Threshold Above Stoll) rating. Thisbasically forces the tester to take the rainwear fabric tothe point at which it breaks open the fabric (EBT) even ifthis is above the second degree burn point (Stoll). Thistest exposes melting FR rainwear materials which passonly small scale tests like Vertical Flammability (2

seconds after flame and 4-6 in. char length), ThermalStability Test (fabric must not melt or drip, separate orignite after five minutes in a 500F oven), or ThermalShrinkage Test (less than 10% after five minutes in a500F oven) to a full scale test like the ASTM F1959 arcrating testing. Every credible fire test except for somevery strong specifications like NFPA 1971 or NFPA 1975for fire fighters use full scale testing in the specification.

3) Fall Protection Harnesses ASTM F887 addressed fallprotection arc ratings back in 2004. Previously there was

978-1-4673-1056-7/10/$26.002010 IEEE


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no standardcalling for arc-rated harnesses. The F887standard requires testing of the harness at 40 cal/cmand doesnt allow melting and dripping of componentsunder those conditions on six new harnesses.

Additionally the standard requires the exposedharnesses to pass an ANSI approved drop test AFTERthe arc exposure. The standard is ONLY on NEW

harnesses and we have in the past few years seenharnesses fail after a years use when retested but ONLYheavy nylon and para-aramid harnesses have beenobserved to pass the test and none of these harnesseshave been involved in injuries to our knowledge to date.Using the para-aramid harnesses would eliminate theconcern about ignition sense these materials are non-melting unlike nylon.

4) Hairnets and Beardnets The new NFPA 70E-2009 nowrequires these items to be arc rated when worn by aworker exposed to a potential arc flash. ASTM F1506 isthe only applicable standard but these items have beenon the market since 2002. Many industries use hairnetsand beardnets, especially the food and pharmaceuticalindustries.

5) High Visibility Clothing The EU EN471 started the driveto making work clothing and workers in general morevisible on the roadway and in the mobile workplace. TheUS ANSI 107 committee took this standard into the USmarket and CSA Z96 has adapted it to the Canadianmarket. The issue for arc rated clothing has been thatthe materials which met the EN 471 standard were notarc rated. Some claim flame resistance but most aremelting flame resistance materials which will increaseburn in arc or flash fire conditions. CSA Z96 evenallowed arc rated and flash fire rated clothing to meet alesser standard for visibility due to the nature of most arcrated and flash fire rated materials which precludes themfrom dyeing with fluorescent dyes. This put the arc andflame resistance on the top of concerns and allowed

bright clothing for worker visibility even if it didnt meetthe more stringent requirements of the ANSI 107 orhigher level CSA standard. Today the bright colordesignation is not used much since there are severalmaterials on the market which meet both F1506 AND

ANSI 107/EN471/CSAZ96. Modacrylic materials (not tobe confused with dangerous FR treated melting acrylics),and blends of modacrylics and other materials can holdfluorescent dyes and maintain inherent flame resistance.

6) Gloves Hand protection is critical for electrical work.The hands are most often the closest body part to the arcpotential and thus receive the majority of arc flash burnswhen unprotected. Two types of gloves are nowcommonly available for arc flash protection.

a. Voltage rated gloves (70E calls these rubberinsulating gloves but I prefer the voltage ratedterm since these gloves could forseeably bemade of other materials especially morefuturistic materials for arc and shock protection).

b. Arc Flash Gloves with no shock protectionvalue.

Voltage rated gloves can be arc tested to determine theincident energy ignition probability AND the arc rating bya standard now in a final proposed version before ASTM.This standard will afford for improvements in flame

resistance of gloves. Though Class 2 gloves (17kVmaximum use voltage rated) have been used for yearswith very few incidents of ignition and no known incidentsof burns the room for improved lighter weight and moreflexible gloves is still a concern. The ASTM standard forgloves D120 has a minimum thickness requirement ongloves which was initially determined to afford better life

and durability but the IEC standard for voltage ratedgloves allows for thinner gloves IF they pass the voltagetest. From a collaboration perspective the advantage ofbeing able to make gloves lighter AND still maintain theirrelative arc rating is a good opportunity for improvement.One new rubber made of a plant from the desert SouthWest United States could hold an opportunity forimprovement if we have standards for arc ratings ofgloves (in process) and performance requirements forglove cut resistance and puncture resistance. The

ASTM specification for leather protectors worn overvoltage rated gloves by OSHA law does not allowanything other than leather. This is not necessarily badand might be the best choice but the failure to make therequirements performance based keeps the status quo

and only allows improvements if cows, goats or horses(in Canada) grow different hides. A case forcollaboration would be to open this standard toimprovements in technology to make a leap from twopairs of gloves for electrical work. This could enhanceworker acceptance of hand protection for shock and arc.The Arc Rated gloves without shock protection takemany forms from the carbon/aramid blended cut resistantgloves to leather to rubber gloves. Rubber gloves madetoday can ignite at some level of arc exposure butbecause of their use for shock protection they are still themost commonly use for arc protection. Arc Rated gloveswhich do not have shock protection can only be wornwhen the task calls for arc protection and does not havean associated shock hazard. Low voltage battery rooms,

racking some breakers and some equipment inspectiontasks such as thermography when the worker or toolsheld by the worker does not cross the restrictedboundary of NFPA 70E.

7) Cleanroom garments Cleanrooms are not used inevery industry but many safety persons are surprisedhow many industries have some level of cleanroomneeds. From Automotive and computer chipmanufacturing to food and pharmaceuticals, cleanroomsare a part of todays high tech industries. Cleanroomscome in many types with some simply needing low lintingclothing. Others need polymeric based materials whichallow almost NO lint or fibrils. Some aramids which arefilament based can meet ASTM F1506. Other aramids

and coated materials can meet the requirements ofspecific industries and now there are about 5 materialsmeeting differing levels of cleanroom requirements.

8) Underwear- The new 2009 NFPA 70E has a substantialchange which will eliminate some hazards. The previousversions of the standard (2000 and 2004) requirednatural fiber underwear. This requirement resulted in afew fatalities (the two we know of were in instances whenworkers were exposed to energies beyond the tablesfootnotes which would have required a flash study and inone the worker did not wear additional protective gear


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required by the work situation). The new standard allowsnatural fiber underwear but does not allow it to count aspart of the protective system. This moves workers tomore and more flame resistant underwear. I recommendflame resistant t-shirts because the majority of arcflashes are upper torso and because this allows a cooleroption for working until exposed to arc (while preparing

the work zone) when the additional long sleevedprotection will be worn. The use of flame resistant t-shirts will also prevent ignition under any incidentalexposures when a worker did not know it could happen.

9) Winterwear This is an issue in many work situations.Some still fallaciously believe that wearing heavy cottonwinterwear OVER a flame resistant shirt will providesome protection. This is false. Many companies arenow issuing flame resistant winterwear which will act as aflash suit when worn with a hood to take advantage ofthe protection afforded by arc-rated winterwear. Somecompanies even allow winterwear or arc-rated rainwearto serve as flash suits year round saving purchasing arcflash suits. Hood are still needed and the winterwear orrainwear system must meet the requirements of a flash

suit in testing.10) Faceshields Faceshields are now required down to

HRC 1. New faceshields are on the market with fullspectrum color recognition. If faceshields havent beenreplaced in the previous year or two they might not bethe most visible on the market. More companies arewearing balaclavas (newly defined in the 2009 standardas meeting HRC 2*). Balaclavas or flash suit hoodsmeet the new standard. Wearing a hood that is not aflash suit hood is questionable.

11) Shoes A few issues exist around shoes.a. Shock protection. Two standards exist for

shoes and shock. One type is called an EH(Electrical Hazard) rating [ATSM F2413 orCAN/CSA Z 195]. These ratings are ONLY for

the soles and only on the lot of the shoes.OSHA recognizes these but gives no guidelineson when they must be worn. The NFPA 70Estandard doesnt directly mention thesestandards. ASTM F1117 standard is for Di-electric Shoes and is the only shoe standardrecognized by the 70E standard. Normal shoesmentioned in several places are not assumed tohave shock protection but we recommendhaving all electricians shoes meet the EHstandards and provide di-electric overshoes forthe specific hazards mentioned in NFPA 70E.Even di-electric shoes are for secondaryshock protection and should not be used as

primary protection from known step potential.The strength of the ASTM F117 standard is thateach shoe is tested by the manufacturer andthe whole boot is tested within an inch from thetop.

b. Arc Flash Protection The standard recognizesthat leather work shoes typically provideexcellent arc flash protection and requires themfor exposures greater than HRC2. Thestandard assumes equal arc flash protectionfrom di-electric shoes.

c. Other hazards this is not directly addressed inthe standard but the new exception allows non-arc rated PPE when the authority having

jurisdiction deems the PPE necessary becauseof a greater hazard. 130.7(C)(15) Exception No.2: Non-FR protective equipment required forunusual hazards may be permitted by the AHJ

(Authority Having Jurisdiction). Manycompanies have arc tested shoes esp. rubberboots to assure they will not ignite in 40 cal/cmarcs for use to protect from other hazards suchas chemicals.

12) Respirators Some companies have tested respiratorsfor arc-ignition and several have done well. They areallowed by the 130.7(C)(15) Exception No. 2: Non-FRprotective equipment required for unusual hazards maybe permitted by the AHJ. Many companies have arctested respirators and some SCBAs to assure they willnot ignite in 40 cal/cm arcs for use to protect from otherhazards such as chemicals and radiation.

13) Disposable arc-rated materials Only one exists whichmeets ASTM F1506 which is a non-woven aramid.

Others work well in arc but dont meet the tear strengthrequirements. These non-safety-related requirementsare slated to be removed from the F1506 standard whichwill allow non-wovens to be chosen by the AHJ and stillmeet the NFPA 70E standard. This was voted sub-committee ballot at ASTM in 2009. Should pass early2010.

14) Hearing Protection While there is no arc-rating forhearing protection, arc tested hearing protection iscommonly available in the form of ear canal inserts.Three types have been tested for ignition probabilityusing the ASTM F1959 test set up and a modified panel.One company is planning to develop an arc tested earmuff in 2009.

15) Hard hats ASTM F18.65 has formed a taskforce to

develop a test method/specification for hard hats for archazards. This has been an issue with materials wornunder hard hats and with foam insert hard hats for lateralimpact protection. The taskforce will meet in early 2010to work on a draft standard using ASTM F2178 as abase.

16) Arc Flash Blankets ASTM F2676-09 has beenpublished and allows ratings of blankets for arcprotection. The blankets receive two ratings.

a. IMAX = the maximum current at which theblanket will hold back an arc flash based on thetesting.

b. BTP = the breakopen threshold in kA-cyclesThe intent for use is to take your maximum fault currentand pick a blanket which exceeds this then determineyour maximum clearing time and be certain the blanketyou have chosen will take the current without breakingopen.If you have a system with 25kA fault current you maychoose a blanket which is 25kA or 40kA. If your clearingtime for 25 kA is 10 cycles then the blanket must begreater than 250 kA-cycles. If you desire a safety factorof 10%, choose a blanket with 275 kA-cycle rating orgreater. No safety factor is currently built into thestandard as it is a test method.


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How these blankets are installed is critical. There is nostandard on installation but they are tested hung tocover/protect the vault from arc flash from a wall.Wrapping is currently not tested and most testing ofwrapping has been less than satisfactory. More work isneeded for a guide to using these blankets. They aremost often used in network systems to protect from

potential cable faults of energized cables when workingon de-energized cables.17) Arc Flash Shields ASTM F2522 Standard Test Method

for Determining the Protective Performance of a ShieldAttached on Live Line Tools or on Racking Rods forElectric Arc Hazards offers test data a cone of protectionfor these devices but this is with a butted electrodeconfiguration. If the arc is more like an ejected arc, theprotection is greater. These shields currently do notrecommend reduction of PPE but they do reduce risk ofburns substantially in certain equipment configurations.They are designed to be used on hotsticks for low andmedium voltage exposures like padmount transformersand on racking screws with an adapter for rackingbreakers. The shields are currently customized for many

applications.

B. Things to Think About When Choosing a Clothing PPESystem

There are many things besides arc rating to look for in arcrated clothing. Moisture regain, feel, initial cost and long termcost of ownership, treatment and reliability of treatment, colorfastness and other safety aspects such as visibility. Theseaspects of clothing must be considered and can be vital but thispaper will not deal with them in depth. I will focus on theaspects which relate more to safety. Primary aspects of clothingsystems to consider in specification include:

1) Does it meet the specific arc rating and flame resistancestandard for this material? ASTM F1506, F1891, F887,

F2178, etc.[2, 4]2) Does the clothing system have the level of arc rating to

meet your arc flash hazard assessment levels? Thisoften requires an arc flash calculation study. The new2009 NFPA 70E [5] makes it more difficult NOT to havean arc flash study.

3) Does it meet other safety criteria for other hazards suchas ANSI 107/EN 471/CSA Z96 High Visibility Clothingstandards or chemical resistance or molten metal splashresistance such as ASTM F955?

4) Is the material permanent in its flame resistance?Inherent fabrics such as aramids, modacrylics, FR rayonfibers and carbonized fibers are inherently flameresistant. Many treated cottons, are renderedpermanently flame resistant by the nature of the chemicaland the treatment process. The process is veryimportant. There are three primary chemical treatmentsfor cotton and the one used in the US has a betterdurability record than the other two. Only one iscommonly available in the US market. However eventhis chemical is not always durable. The manufacturershould have demonstrated competence in treatment anda documented testing process for assuring durability ofthe flame resistant materials.

5) Choose the right manufacturers and service providers.There are more than five in the world which use adurable FR treatment process that is time tested. This iscritical if not choosing an inherently flame resistant arc-rated material. Investing in an arc-rated clothing systemis a value proposition and having serviceable garments iscritical. Using an interesting fabric from a smaller player

who doesnt have stock is not a good idea. Safetygarments need to be readily available in a range of sizeswith a reasonable delivery time. Not having stock shouldbe a negative consideration.

6) Comfort is an important consideration. Workers whowear the clothing all the time are more likely to be

protected?7) Is the hood system if used visible and wearable?

a. Considering fans or breathing apparatusesdepending on other factors but breathing insidehoods is critical. If hoods are worn more than afew minutes at a time they should be equippedwith fans or a blower of some sort. Areplaceable or repairable fan unit will savemoney in the long run and the noise level,

battery life and effectiveness of the fan onfogging and breathing should be considered.

b. Is the face piece of the hood too close to theface? Some hood manufacturers cut corners inthe test method by backing the face piece veryclose to the face. This makes the arc ratinghigher but causes fogging even with an anti fogtreatment.

c. Will I have to wear a respirator at times in thehood? Then the face piece location is evenmore critical

d. Do I have shock hazards near the head in thework process? If this is the case such as in linework you might consider a hood which goesUNDER the hard hat such as the newer

goggle/balaclava systems. Shock is the biggestkiller in electrical incidents so it should alwaysbe a consideration.

e. Does the hood system allow replacement offacepieces? Unreplaceable face pieces willmean greater cost in the long run to replace thehood or reduced worker sight as time goes on.Proper care can extend face piece life butreplaceable face pieces are much more costeffective in the long run. Additionally, as face

piece visibility increases these hoods canreplace face pieces with more visible ones if themanufacturer approves.

f. What is the peripheral vision allowable in thehood? Again, some designs allow much morevisibility than others.

8) Other PPE requirements?a. Have melting components of the PPE been

considered?b. What about disposable garments worn OVER

or under arc rated clothing for otherhazards/reasons. Arc rated garments such asdisposables made of a wood pulp flameresistant treated fabric are commonly available


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to replace polyester melting fabrics commonlyused for arc clothing.

C. Care for Arc Rated PPE1) Home Laundering the new ASTM F2757 standard

gives guidelines for home laundering similar to the longexistent industrial laundering standard. This guide maybe used if contaminants pose no danger to the worker in

the laundering process and can be removed with normalhome laundering. Toxic or hazardous contaminantsrequire special handling and laundry or disposaltechniques.

2) Industrial Laundering the updated ASTM F1449standard is more open to the many changes in industriallaundering and give great leeway for launderers to usenew chemical and physical techniques to remove soilsmore fully, with more environmentally friendly methods.

3) Other cleaning methods Dry Cleaning still has nostandards but the guides recommend not cleaning arcrated or flame resistant garments with flammablesubstances.

4) Contamination flammable or combustible contaminantswill reduce the protection of arc rated materials until

effectively washed out. Materials like DEET (a commoncomponent in mosquito repellants) are flammable in arcflash exposures. Using these materials on flameresistant clothing entails risk. The same is true ofhydraulic oil, and other carbon based contaminants. Insome concentrations conditions reach the point ofhydrocarbon loading such that the flame resistance ofthe fabric will be compromised and unable to preventcontinued burning of the contaminated area. Clothingshould be cleaned regularly, in most cases daily but ifhigh contamination work is being performed disposableor limited use arc rated clothing is recommended to beused over the daily wear and removed as contaminatedto prevent hazard from hydrocarbon loading.

III. CONCLUSIONS

Arc-rated clothing fitting just about every need is nowavailable and more affordable than ever. Finding the rightclothing system is easier in the past three years than everbefore and the competitive environment makes the affordabilitya certainty. Companies are moving to arc-rated clothing morethan ever before and the choices of specialty clothing will meetmost any need in industry.

IV. REFERENCES

[1] Hoagland, H; Morrow, B., "Using Rainwear as Switching

Jackets: A Reasonable Solution for Electric ArcExposure, IEEE Transactions on Industry Applications,Volume 36, Issue 5, pp 1241-1246, Sep/Oct 2000.

[2] All the standards are mentioned in the NFPA 70EStandard are related to clothing.

ASTM F1959, Standard Test Method for Determining theArc Thermal Performance Value of Materials for ClothingASTM F1506, Standard Performance Specification forFlame Resistant Textile Materials for Wearing Apparel forUse by Electrical Workers Exposed to Momentary Electric

Arc and Related Thermal HazardsASTM F1891, Standard Specification for Arc and FlameResistant Rainwear

ASTM F2178, Standard Test Method for Determining theArc Rating of Face Protective ProductsASTM F887 Standard Specifications for Personal ClimbingEquipment,

ASTM F2676 Standard Test Method for Determining theProtective Performance of an Arc Protective Blanket forElectric Arc Hazards

ASTM F2522 Standard Test Method for Determining theProtective Performance of a Shield Attached on Live LineTools or on Racking Rods for Electric Arc Hazards

ASTM F2757 Standard Guide for Home Laundering Careand Maintenance of Flame, Thermal and Arc Resistant

ClothingASTM F1449 Standard Guide for Industrial Laundering ofFlame, Thermal, and Arc Resistant Clothing

All mentioned ASTM standards are available fromwww.astm.org or ASTM International, 100 Barr HarborDrive, West Conshohocken, PA, 19428.

[4] Hugh Hoagland, Arc Flash Safety: Know WhichStandard You Should Be Using, Industrial Safety &Hygiene News, July 2007.

[5] NFPA 70E, 2009 Electrical Safety in the Workplace,NFPA Quincy, MA (www.nfpa.org).

[6] Hoagland Elihu "Hugh" "PPE in the electric arc: A case forcollaboration", Electrical Safety Workshop, 2009. IEEEIAS Volume , Issue , 2-6 Feb. 2009 Page(s):1 4.

[7] Hugh Hoagland, "Disposable FR Garments: What Are theDifferences?", Electrical Construction & Maintenance(EC&M) magazine, January 2008.

V. VITA

Elihu Hugh Hoagland received his BA from KentuckyWesleyan College and did two years of post-bacc and graduatework at University of Louisville. Hugh is a trained analyticalchemist and began arc testing in 1994 with LG&E Energy.Hugh now sits on US and international committees on arc flashtesting and works developing PPE systems, methodsdevelopment and training in his companies which include

ArcWear.com, ArcStore.com and e-Hazard.com. He is amember of the IEEE 1584 committee and an author of several

previous IEEE papers in RECP, PCIC and ESW.

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06164466 Nfpa f0e and Arc Flash Ppe Update