ASTM F2178-02
(Test Method)Standard Test Method for Determining The Arc Rating Of Face Protective Products
Standard Test Method for Determining The Arc Rating Of Face Protective Products
SCOPE
1.1 This test method is used to measure the arc rating of products intended for use as face protection for workers exposed to electric arcs.
1.2 This test method will measure the arc rating of face protective products. The faceshield or other applicable portions of the complete product must meet ANSI Z87.1. This excludes the textile or non ANSI Z87.1 testable parts of the hood assemblies or other tested products. This standard does not measure optical and impact properties (See ANSI Z87.1).
1.3 The materials used in this method are in the form of faceshields attached to the head by protective helmets (hard hats), headgear, or hood assemblies.
1.3.1 Fabric layers used in hood assemblies or other items tested under this standard meet flammability requirements of Specification F 1506.
1.4 This standard shall be used to measure and describe the properties of materials, products, or assemblies in response to convective and radiant energy generated by an electric arc under controlled laboratory conditions and does not purport to predict damage from light other than the thermal aspects measured.
1.5 Units—The values stated in either SI units or in other units shall be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system must be used independently of the other, without combining values in any way.
1.6 This standard shall not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire assessment, which takes into account all of the factors, which are pertinent to an assessment of the fire hazard of a particular end use.
1.7 This standard does not purport to describe or appraise the effect of the electric arc fragmentation explosion and subsequent molten metal splatter, which involves the pressure wave containing molten metals and possible fragments of other materials except to the extent that heat energy transmission due to these arc explosion phenomena is reduced by test specimens.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautions, see Section 7.
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Designation:F2178–02
Standard Test Method for
Determining The Arc Rating Of Face Protective Products
This standard is issued under the fixed designation F2178; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope wavecontainingmoltenmetalsandpossiblefragmentsofother
materialsexcepttotheextentthatheatenergytransmissiondue
1.1 This test method is used to measure the arc rating of
tothesearcexplosionphenomenaisreducedbytestspecimens.
products intended for use as face protection for workers
1.8 This standard does not purport to address all of the
exposed to electric arcs.
safety concerns, if any, associated with its use. It is the
1.2 This test method will measure the arc rating of face
responsibility of the user of this standard to establish appro-
protectiveproducts.Thefaceshieldorotherapplicableportions
priate safety and health practices and determine the applica-
of the complete product must meetANSI Z87.1.This excludes
bility of regulatory limitations prior to use. For specific
the textile or non ANSI Z87.1 testable parts of the hood
precautions, see Section 7.
assemblies or other tested products. This standard does not
measure optical and impact properties (See ANSI Z87.1).
2. Referenced Documents
1.3 The materials used in this method are in the form of
2.1 ASTM Standards:
faceshields attached to the head by protective helmets (hard
C177 Test Method for Steady-State Heat Flux Measure-
hats), headgear, or hood assemblies.
ments and Thermal Transmission Properties by Means of
1.3.1 Fabric layers used in hood assemblies or other items
the Guarded-Hot-Plate Apparatus
tested under this standard meet flammability requirements of
D123 Terminology Relating to Textiles
Specification F1506.
D4391 Terminology Relating to the Burning Behavior of
1.4 This standard shall be used to measure and describe the
Textiles
properties of materials, products, or assemblies in response to
E457 TestMethodforMeasuringHeat-TransferRateUsing
convective and radiant energy generated by an electric arc
a Thermal Capacitance (Slug) Calorimeter
under controlled laboratory conditions and does not purport to
F1494 Terminology Relating to Protective Clothing
predict damage from light other than the thermal aspects
F1506 Specification for Flame Resistant Textile Materials
measured.
for Wearing Apparel for Use by Electrical Workers Ex-
1.5 Units—The values stated in either SI units or in other
posed to Momentary Electric Arc and Related Thermal
unitsshallberegardedseparatelyasstandard.Thevaluesstated
Hazards
in each system may not be exact equivalents; therefore, each
F1958 Test Method for Determining the Ignitability of
system must be used independently of the other, without
Non-Flame-Resistant Materials for Clothing by Electric
combining values in any way.
Arc Exposure Method Using Mannequins
1.6 This standard shall not be used to describe or appraise
F1959 Test Method for Determining the Arc Thermal
the fire hazard or fire risk of materials, products, or assemblies
Performance Value of Materials for Clothing
under actual fire conditions. However, results of this test may
2.2 ANSI/IEEE Standards:
be used as elements of a fire assessment, which takes into
IEEE Standard Dictionary of Electrical and Electronics
account all of the factors, which are pertinent to an assessment
Terms
of the fire hazard of a particular end use.
1.7 This standard does not purport to describe or appraise
the effect of the electric arc fragmentation explosion and
Annual Book of ASTM Standards, Vol 04.06.
subsequent molten metal splatter, which involves the pressure
Annual Book of ASTM Standards, Vol 07.01.
Annual Book of ASTM Standards, Vol 07.02.
Annual Book of ASTM Standards, Vol 15.03.
1 6
This test method is under the jurisdiction of ASTM Committee F18 on Annual Book of ASTM Standards, Vol 11.03.
Electrical Protective Equipment for Workers and is the direct responsibility of Annual Book of ASTM Standards, Vol 10.03.
Subcommittee F18.65 on Wearing Apparel. AvailablefromInstituteofElectricalandElectronicsEngineers,Inc.,445Hoes
Current edition approved April 10, 2002. Published June 2002. Ln., P.O. Box 1331, Piscataway, NJ 05584-1331.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F2178
ANSI Z87.1-1999 Practice for Occupational and Educa- 3.2.13 calorimeter, n—a device used in which the heat
tional Eye and Face Protection measured causes a change in state.
3.2.13.1 Discussion—Thedeterminationofheatenergy,asa
3. Terminology consequence of an electrical arc exposure, is made in this
standardbymeasuringthechangeintemperatureofanexposed
3.1 Definitions—For definitions of other textile terms used
copper slug of specific geometry and mass during finite time
in this method, refer to terminology in Terminology D123,
intervals.
D4391 and F1494.
3.2.14 closure,n—pointonsupplycurrentwaveformwhere
3.2 Definitions of Terms Specific to This Standard:
arc is initiated.
3.2.1 afterflame, n—persistent flaming of a material after
3.2.15 deformation, n—for electric arc testing of face pro-
the ignition source has been removed.
tective products, the sagging of material greater than 3 in. or
3.2.2 afterflame time, n—the length of time for which a
melting in any manner that the faceshield/window touches any
material continues to flame after the ignition source has been
part of the body.
removed.
3.2.16 delta peak temperature, n—difference between the
3.2.3 arc duration, n—time duration of the arc, s.
maximumtemperatureandtheinitialtemperatureofthesensor
3.2.4 arc energy, vi dt, n—sum of the instantaneous arc
during the test, °C.
voltage values multiplied by the instantaneous arc current
values multiplied by the incremental time values during the 3.2.17 dripping, n—in electric arc testing, a material re-
sponse evidenced by flowing of the fiber polymer or the
arc, J.
faceshield window polymer.
3.2.5 arc gap, n—distance between the arc electrodes, in.
3.2.6 arc rating, n—a value which indicates the arc perfor- 3.2.18 electricarcignition,n—inelectricarctestingofface
manceofamaterialorsystemofmaterials;eitherATPVorE . protective products, the initiation of combustion as related to
BT
electric arc exposure, a response that causes the ignition of
3.2.6.1 Discussion—When the arc rating represents the
ATPV, it shall be reported as Arc Rating (ATPV). When Arc textile test specimen material which is accompanied by heat
and light, and then subsequent burning for at least 5 s, and
Rating represents the E , it shall be designated asArc Rating
BT
(E ).E isdeterminedwhentheATPVcannotbedetermined. consumption of at least 25% of the test specimen area.
BT BT
3.2.7 arc thermal performance value (ATPV), n—in arc 3.2.18.1 Discussion—For multilayer specimens, consump-
testingfaceprotectiveproducts,theincidentenergyonafabric tion of the innermost FR layer must be at least 25%.
or material that results in sufficient heat transfer through the
3.2.19 faceshield, n—a protective device commonly in-
fabric or material to cause the 50% probability of the onset of
tended to shield the wearer’s face, or portions thereof, in
a second-degree burn based on the Stoll curve. addition to the eyes, from certain hazards.
3.2.8 arc voltage, n—voltage across the gap caused by the
3.2.20 heat attenuation factor, HAF, n—in electric arc
current flowing through the resistance created by the arc gap
testing,theaverageofthepercentoftheincidentenergywhich
(V).
is blocked by a material.
3.2.9 asymmetrical arc current, n—the total arc current
3.2.20.1 Discussion—In Arc Testing of Face Protective
produced during closure; it includes a direct component and a
Products, HAF (face) is based on the highest sensor reading
symmetrical component, A.
among the four head sensors for each head exposure.
3.2.10 blowout, n—the extinguishing of the arc caused by a
3.2.21 heat flux, n—the thermal intensity indicated by the
magnetic field.
amountofenergytransmittedperunitareaandtime(cal/cm s).
3.2.11 breakopen, n—in electric arc testing, a material
3.2.22 i t, n—sum of the instantaneous arc current values
response evidenced by the formation of one or more holes in
squared multiplied by the incremental time values during the
the material which may allow thermal energy to pass through
arc, A /s.
material.
3.2.23 incident energy monitoring sensors, n—sensors
3.2.11.1 Discussion—Thespecimenisconsideredtoexhibit
mounted on each side of each head, using calorimeters, not
breakopen when any hole in the material or fabric is at least
covered by specimens, used to measure incident energy.
one-half square inch in area or at least one inch in any
3.2.24 incident exposure energy (E), n—in arc testing, the
i
dimension. For textile materials, single threads across the
total incident energy delivered to monitor calorimeter sensors
opening or hole does not reduce the size of the hole for the 2
as a result of the arc exposure, cal/cm .
purposesofthisstandard. In multiple layer specimensofflame
3.2.24.1 Discussion—In an arc test exposure, incident ex-
resistant material, all the layers must breakopen to meet the
posure energy for a specimen is determined from the average
definition.
of the measured incident energy from the respective two
3.2.12 breakopen threshold energy (E ), n—in arc testing
BT
monitor sensors adjacent to the test specimen.
face protective products, the incident energy on a fabric or
3.2.25 material response, n—material response to an elec-
material that represents the 50% probability that a breakopen
tricarcisindicatedbythefollowingterms:breakopen,melting,
response will occur.
dripping, deformation, afterflame time, shrinkage, and electric
arc ignition.
3.2.26 melting, n—in testing face protective products, a
material response evidenced by softening of the fiber polymer
Available from American National Standards Institute, 25 W. 43rd St., 4th
Floor, New York, NY 10036. or the faceshield window polymer.
F2178
3.2.27 peak arc current, n—maximum value of the AC arc 4.1.2 The thermal energy exposure and heat transport re-
current, A. sponse of the test specimen(s) are measured with copper slug
3.2.28 RMS arc current, n—root mean square of theAC arc calorimeters. The change in temperature versus time is used,
current, A. along with the known thermo-physical properties of copper to
3.2.29 shrinkage, n—in testing face protective products, a determinetherespectiveheatenergiesdeliveredtoandthrough
material response evidenced by reduction in specimen size of the specimen(s).
the fabric or the faceshield window. 4.2 This procedure incorporates incident energy monitoring
3.2.30 Stoll curve, n—curve produced from data on human sensors.
tissue tolerance to heat and used to predict the onset of 4.3 Productandmaterialperformanceforthisprocedureare
second-degree burn injury (See Table 1). determined by comparing the amount of heat energy generated
3.2.31 time to delta peak temperature, n—the time from by the arc flash on monitor sensors with the energy transferred
beginning of the initiation of the arc to the time the delta peak byorthroughthetestspecimen(s)andmeasuredbysensorson
temperature is reached, s. the mannequin head.
3.2.32 X/R ratio, n—the ratio of system inductive reactance 4.4 Product and material responses shall be further de-
to resistance. scribed by recording the observed effects of the electric arc
3.2.32.1 Discussion—It is proportional to the L/R ratio of exposure on the specimens using the terms in the Report
time constant, and is, therefore, indicative of the rate of decay section.
of any DC offset.Alarge X/R ratio corresponds to a large time
5. Significance and Use
constant and a slow rate of decay.
5.1 Thistestmethodisintendedforthedeterminationofthe
4. Summary of Test Method
arc rating of a product/design, intended for use as face
4.1 This test method determines the heat transport response protection for workers exposed to electric arcs.
5.1.1 Because of the variability of the arc exposure, differ-
across a material, fabric, or fabric system when exposed to the
heatenergyfromanelectricarc.Thisheattransportresponseis ent heat transmission values may result for individual sensors.
The results of each sensor are evaluated in accordance with
assessed versus the Stoll curve, an approximate human tissue
tolerance predictive model that projects the onset of a second- Section 12.
5.2 This test method maintains the specimen in a static,
degree burn injury (found in Table 1).
4.1.1 Productsaremountedonthestandardmannequinhead vertical position and does not involve movement except that
resulting from the exposure.
containing copper slug calorimeters inserted in the eyes,
mouth, and chin positions. During this procedure, the amount 5.3 This test method specifies a standard set of exposure
conditions. Different exposure conditions may produce differ-
of heat energy transferred by the specimen face protective
products is measured during and after exposure to an electric ent results.
arc.
NOTE 1—In addition to the standard set of exposure conditions, other
conditionsrepresentativeoftheexpectedhazardmaybeusedandshallbe
TABLE 1 Human Tissue Tolerance To Heat—Second-degree
reported should this data be cited.
A
Burn
Exposure
6. Apparatus
Heat Flux Total Heat
Time
2 2 2 2
6.1 General Arrangement for Determining Rating Using
s kW/m cal/cm s kW/m cal/cm s
Sensor Heads and Monitor Sensors—The test apparatus shall
1 50 1.2 50 1.20
2 31 0.73 61 1.46 consist of supply bus, arc controller, recorder, arc electrodes,
3 23 0.55 69 1.65
two (or optionally three) four-sensor heads, and four (or
4 19 0.45 75 1.80
optionally six) incident energy monitoring sensors. The arc
5 16 0.38 80 1.90
6 14 0.34 85 2.04 exposure shall be monitored with two incident energy-
7 13 0.30 88 2.10
monitoring sensors for each head.
8 11.5 0.274 92 2.19
6.1.1 Arrangement of the Four-Sensor Heads—The stan-
9 10.6 0.252 95 2.27
10 9.8 0.233 98 2.33 dard test set up is three four-sensor heads spaced at 120°
11 9.2 0.219 101 2.41
around the arc (Fig. 1). If you only use one video camera to
12 8.6 0.205 103 2.46
view the tests, place it so that the front of two of the heads can
13 8.1 0.194 106 2.52
14 7.7 0.184 108 2.58 be viewed, and you may remove one of the heads to facilitate
15 7.4 0.177 111 2.66
viewing. Locate each head vertically to the arc electrodes as
16 7.0 0.168 113 2.69
showninFig.2.Youmayuseonlycalorimetrydatafromheads
17 6.7 0.160 114 2.72
18 6.4 0.154 116 2.77
that are viewed from the
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