ASTM F2703-21

Standard Test Method for Unsteady-State Heat Transfer Evaluation of Flame-Resistant Materials for Clothing with Burn Injury Prediction

SIGNIFICANCE AND USE
5.1 This test method is intended for the determination of a thermal performance estimate value of a material, a combination of materials, or a comparison of different materials used in flame-resistant clothing for workers exposed to combined convective and radiant thermal hazards.  
5.2 This test method evaluates a material’s heat transfer properties when exposed to a heat exposure at a constant value and specific duration. Air movement at the face of the specimen and around the calorimeter can affect the measured heat transferred due to forced convective heat losses. Minimizing air movement around the specimen and test apparatus will aid in the repeatability of the results.  
5.3 This test method accounts for the thermal energy stored in the exposed test specimen after the heat exposure has ceased. Higher values of thermal performance estimate ratings determined in this test associate to higher values of thermal (convective and radiative) energy protection against a predicted skin burn injury.  
5.4 This test method maintains the specimen in a static, horizontal position and does not involve movement except that resulting from the exposure.  
5.5 This test method specifies a standardized 84 ± 2 kW/m2 (2 ± 0.05 cal/cm2·s) exposure condition. Different exposure conditions have the potential to produce different results. Other exposure conditions representative of the expected hazard are allowed but shall be reported with the results along with a determination of the exposure energy level stability.  
5.6 This test method contains optional provisions for conducting certification testing against a prescribed thermal performance estimate value.
SCOPE
1.1 This test method measures the non-steady state heat transfer through flame-resistant materials for clothing subjected to a combined convective and radiant heat exposure.  
1.1.1 This test method is not applicable to materials that are not flame resistant.
Note 1: The determination of a material’s flame resistance shall be made prior to testing and done in accordance with the applicable performance or specification standard, or both, for the material’s end use.  
1.1.2 This test method accounts for the thermal energy contained in an exposed test specimen after the standardized combined convective and radiant heat exposure has ceased and is used to estimate performance to a predicted second-degree skin burn injury.  
1.2 This test method is used to measure and describe the response of materials, products, or assemblies to heat under controlled conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound or other units that are commonly used for thermal testing.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 13.340.10 - Protective clothing
• Technical Committee: F23 - Personal Protective Clothing and Equipment
• Drafting Committee: F23.80 - Flame and Thermal

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F2703 − 21
Standard Test Method for
Unsteady-State Heat Transfer Evaluation of Flame-Resistant
1
Materials for Clothing with Burn Injury Prediction
This standard is issued under the fixed designation F2703; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
2
1.1 This test method measures the non-steady state heat 2.1 ASTM Standards:
transfer through flame-resistant materials for clothing sub- D123Terminology Relating to Textiles
jected to a combined convective and radiant heat exposure. D1777Test Method for Thickness of Textile Materials
1.1.1 This test method is not applicable to materials that are D3776/D3776MTest Methods for Mass Per Unit Area
not flame resistant. (Weight) of Fabric
E457Test Method for Measuring Heat-Transfer Rate Using
NOTE 1—The determination of a material’s flame resistance shall be
a Thermal Capacitance (Slug) Calorimeter
made prior to testing and done in accordance with the applicable
F1494Terminology Relating to Protective Clothing
performance or specification standard, or both, for the material’s end use.
1.1.2 This test method accounts for the thermal energy
3. Terminology
contained in an exposed test specimen after the standardized
3.1 Definitions:
combinedconvectiveandradiantheatexposurehasceasedand
3.1.1 breakopen, n—in testing thermal protective materials,
is used to estimate performance to a predicted second-degree
amaterialresponseevidencedbytheformationofaholeinthe
skin burn injury.
test specimen during the thermal exposure that may result in
1.2 This test method is used to measure and describe the
the exposure energy in direct contact with the heat sensor.
response of materials, products, or assemblies to heat under
3.1.1.1 Discussion—The specimen is considered to exhibit
controlled conditions, but does not by itself incorporate all
breakopen when a hole is produced as a result of the thermal
factors required for fire hazard or fire risk assessment of the 2 2
exposure that is at least 3.2 cm (0.5 in. ) in area or at least
materials, products, or assemblies under actual fire conditions.
2.5cm (1.0 in.) in any dimension. Single threads across the
1.3 The values stated in SI units are to be regarded as opening or hole do not reduce the size of the hole for the
standard. The values given in parentheses are mathematical purposes of this test method.
conversions to inch-pound or other units that are commonly
3.1.2 charring, n—the formation of a carbonaceous residue
used for thermal testing.
as the result of pyrolysis or incomplete combustion.
1.4 This standard does not purport to address all of the
3.1.3 dripping,n—amaterialresponseevidencedbyflowing
safety concerns, if any, associated with its use. It is the
of the polymer.
responsibility of the user of this standard to establish appro-
3.1.4 embrittlement, n—the formation of a brittle residue as
priate safety, health, and environmental practices and deter-
a result of pyrolysis or incomplete combustion.
mine the applicability of regulatory limitations prior to use.
3.1.5 heat flux, n—the thermal intensity indicated by the
1.5 This international standard was developed in accor-
2
amountofenergytransmitteddividedbyareaandtime;kW/m
dance with internationally recognized principles on standard-
2
(cal/cm ·s).
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.1.6 ignition, n—the initiation of combustion.
mendations issued by the World Trade Organization Technical
3.1.7 melting, n—a material response evidenced by soften-
Barriers to Trade (TBT) Committee.
ing of the polymer.
3.1.8 response to heat exposure, n—in testing the resistance
to heat transfer of thermal protective materials, the observable
1
ThistestmethodisunderthejurisdictionofASTMCommitteeF23onPersonal
ProtectiveClothingandEquipmentandisthedirectresponsibilityofSubcommittee
2
F23.80 on Flame and Thermal. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2021. Published November 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2008. Last previous edition approved in 2013 as F2703–08 (2013). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/F2703-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2703 − 08 (Reapproved 2013) F2703 − 21
Standard Test Method for
Unsteady-State Heat Transfer Evaluation of Flame Resistant
Flame-Resistant Materials for Clothing with Burn Injury
1
Prediction
This standard is issued under the fixed designation F2703; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method measures the non-steady state heat transfer through flame resistant flame-resistant materials for clothing
subjected to a combined convective and radiant heat exposure.
1.1.1 This test method is not applicable to materials that are not flame resistant.
NOTE 1—The determination of a material’s flame resistance shall be made prior to testing and done in accordance with the applicable performance or
specification standard, or both, for the material’s end-use.end use.
1.1.2 This test method accounts for the thermal energy contained in an exposed test specimen after the standardized combined
convective and radiant heat exposure has ceased and is used to estimate performance to a predicted second-degree skin burn injury.
1.2 This test method is used to measure and describe the response of materials, products, or assemblies to heat under controlled
conditions, but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products,
or assemblies under actual fire conditions.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to
inch-pound or other units that are commonly used for thermal testing.
1.4 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
1
This test method is under the jurisdiction of ASTM Committee F23 on Personal Protective Clothing and Equipment and is the direct responsibility of Subcommittee
F23.80 on Flame and Thermal.
Current edition approved June 1, 2013Nov. 1, 2021. Published June 2013November 2021. Originally approved in 2008. Last previous edition approved in 20082013 as
F2703 - 08.F2703 – 08 (2013). DOI: 10.1520/F2703-08R13.10.1520/F2703-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F2703 − 21
D123 Terminology Relating to Textiles
D1776 Practice for Conditioning and Testing Textiles
D1777 Test Method for Thickness of Textile Materials
D3776D3776/D3776M Test Methods for Mass Per Unit Area (Weight) of Fabric
E457 Test Method for Measuring Heat-Transfer Rate Using a Thermal Capacitance (Slug) Calorimeter
F1494 Terminology Relating to Protective Clothing
3. Terminology
3.1 Definitions:
3.1.1 breakopen, n—in testing thermal protective materials, a material response evidenced by the formation of a hole in the test
specimen during the thermal exposure that may result in the exposure energy in direct contact with the heat sensor.
3.1.1.1 Discussion—
The specimen is considered to exhibit breakopen when a hole is produced as a result of the thermal exposure that is at least 3.2
2 2
cm (0.5 in. ) in area or at least 2.5 cm 2.5 cm (1.0 in.) in any dimension. Single threads across the opening or hole do not reduce
the size of the hole for the purposes of this test method.
3.1.2 charring, n—the formation of a carbonaceous residue as the result of pyrolysis or incomplete combustion.
3.1.3 dripping, n—a material response evidenced by flowing of the polymer.
3.1.4 embrittlement, n—th
...