ASTM_F_2703_-_08_2013.pdf

Designation:F270308(Reapproved 2013)Standard Test Method forUnsteady-State Heat Transfer Evaluation of Flame ResistantMaterials for Clothing with Burn Injury Prediction1This standard is issued under the fixed designation F2703;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method measures the non-steady state heattransfer through flame resistant materials for clothing subjectedto a combined convective and radiant heat exposure.1.1.1 This test method is not applicable to materials that arenot flame resistant.NOTE1The determination of a materials flame resistance shall bemade prior to testing and done in accordance with the applicableperformance or specification standard,or both,for the materials end-use.1.1.2 This test method accounts for the thermal energycontained in an exposed test specimen after the standardizedcombined convective and radiant heat exposure has ceased andis used to estimate performance to a predicted second-degreeskin burn injury.1.2 This test method is used to measure and describe theresponse of materials,products,or assemblies to heat undercontrolled conditions,but does not by itself incorporate allfactors required for fire hazard or fire risk assessment of thematerials,products,or assemblies under actual fire conditions.1.3 The values stated in SI units are to be regarded asstandard.The values given in parentheses are mathematicalconversions to inch-pound or other units that are commonlyused for thermal testing.1.4 This standard does not purport to address the safetyconcerns,if any,associated with its use.It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD1777 Test Method for Thickness of Textile MaterialsD3776 Test Methods for Mass Per Unit Area(Weight)ofFabricE457 Test Method for Measuring Heat-Transfer Rate Usinga Thermal Capacitance(Slug)CalorimeterF1494 Terminology Relating to Protective Clothing3.Terminology3.1 Definitions:3.1.1 breakopen,nin testing thermal protective materials,a material response evidenced by the formation of a hole in thetest specimen during the thermal exposure that may result inthe exposure energy in direct contact with the heat sensor.3.1.1.1 DiscussionThe specimen is considered to exhibitbreakopen when a hole is produced as a result of the thermalexposure that is at least 3.2 cm2(0.5 in.2)in area or at least 2.5cm(1.0 in.)in any dimension.Single threads across theopening or hole do not reduce the size of the hole for thepurposes of this test method.3.1.2 charring,nthe formation of a carbonaceous residueas the result of pyrolysis or incomplete combustion.3.1.3 dripping,na material response evidenced by flowingof the polymer.3.1.4 embrittlement,nthe formation of a brittle residue asa result of pyrolysis or incomplete combustion.3.1.5 heat flux,nthe thermal intensity indicated by theamount of energy transmitted divided by area and time;kW/m2(cal/cm2s).3.1.6 ignition,nthe initiation of combustion.3.1.7 melting,na material response evidenced by soften-ing of the polymer.3.1.8 unsteady state heat transfer value,nin testing ofthermal protective materials,a quantity expressed as thetime-dependent difference between the incident and exitingthermal energy values normal to and across two definedparallel surfaces of an exposed thermal insulative material.3.1.9 thermal performance estimate(TPE),nin testing ofthermal protective materials,the cumulative amount of energyidentified by the intersection of a measured time-dependent1This test method is under the jurisdiction ofASTM Committee F23 on PersonalProtective Clothing and Equipment and is the direct responsibility of SubcommitteeF23.80 on Flame and Thermal.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 2008.Last previous edition approved in 2008 as F2703-08.DOI:10.1520/F2703-08R13.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 heat transfer response through a subject material to a time-dependent,empirical predicted second-degree skin burn injuryperformance curve3,expressed as a rating or value;J/cm2(cal/cm2).3.1.10 response to heat exposure,nin testing the resis-tance to heat transfer of thermal protective materials,theobservable response of the material to the energy exposure asind