ASTM F2733-21

Standard Specification for Flame-Resistant Rainwear for Protection Against Flame Hazards

SIGNIFICANCE AND USE
4.1 This specification covers the minimum performance criteria for flame resistance and other requirements for rainwear used by workers with the potential to be simultaneously exposed to wet weather conditions and either hydrocarbon or petrochemical industrial fires.  
4.2 The purchaser has the option to perform or have performed any of the tests required by this specification in order to verify the performance of the rainwear.  
4.3 This specification for rainwear shall not be construed as a requirement for the use of any particular rainwear material.
SCOPE
1.1 This specification establishes applicable test methods, minimum physical and thermal performance criteria, a suggested sizing guide, and suggested purchasing information for rainwear for use by workers who are potentially exposed to industrial hydrocarbon fires or other petrochemical fire hazards.  
1.1.1 This specification does not apply to rainwear used for thermal electric arc flash hazards. Specification of rainwear for these electric arc flash hazards is addressed in Specification F1891.  
1.2 The objective of this specification is to prescribe function and performance criteria for rainwear that meets a minimum level of thermal and physical performance when exposed to a laboratory-simulated fire exposure.  
1.3 This specification is not intended to serve as a detailed manufacturing or purchasing specification, but can be referenced in purchase contracts to ensure that minimum performance requirements are met.  
1.4 Controlled laboratory tests used to determine compliance with the performance requirements of this specification shall not be deemed as establishing performance levels for all situations to which wearers of this protective clothing are potentially exposed.  
1.5 This specification does not attempt to establish in-service care and use of this flame-resistant rainwear.  
1.6 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.  
1.7 The following safety hazards caveat pertains to Sections 7 and 9 of this specification. 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.  
1.8 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-Jan-2021
• ICS: 13.340.10 - Protective clothing
• Technical Committee: F23 - Personal Protective Clothing and Equipment
• Drafting Committee: F23.80 - Flame and Thermal

Relations

• Refers: ASTM E96/E96M-24 - Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials
• Effective Date: 01-Mar-2024
• Refers: ASTM E96/E96M-23 - Standard Test Methods for Gravimetric Determination of Water Vapor Transmission Rate of Materials
• Effective Date: 15-Nov-2023
• Refers: ASTM F1891-19 - Standard Specification for Arc and Flame Resistant Rainwear
• Effective Date: 01-Jan-2019
• Refers: ASTM D4391-18 - Standard Terminology Relating to The Burning Behavior of Textiles
• Effective Date: 01-May-2018
• Refers: ASTM D3776/D3776M-09a(2017) - Standard Test Methods for Mass Per Unit Area (Weight) of Fabric
• Effective Date: 15-Jul-2017
• Refers: ASTM F1930-17 - Standard Test Method for Evaluation of Flame Resistant Clothing for Protection Against Fire Simulations Using an Instrumented Manikin
• Effective Date: 01-Apr-2017
• Refers: ASTM D123-17 - Standard Terminology Relating to Textiles
• Effective Date: 01-Mar-2017
• Refers: ASTM D4391-16e1 - Standard Terminology Relating to The Burning Behavior of Textiles
• Effective Date: 15-Feb-2016
• Refers: ASTM D4391-16 - Standard Terminology Relating to The Burning Behavior of Textiles
• Effective Date: 15-Feb-2016
• Refers: ASTM D123-15b - Standard Terminology Relating to Textiles
• Effective Date: 15-Sep-2015
• Refers: ASTM D123-15a - Standard Terminology Relating to Textiles
• Effective Date: 01-Sep-2015
• Refers: ASTM E96/E96M-15 - Standard Test Methods for Water Vapor Transmission of Materials
• Effective Date: 01-May-2015
• Refers: ASTM D123-15 - Standard Terminology Relating to Textiles
• Effective Date: 01-Apr-2015
• Refers: ASTM F1930-15 - Standard Test Method for Evaluation of Flame Resistant Clothing for Protection Against Fire Simulations Using an Instrumented Manikin
• Effective Date: 01-Feb-2015
• Refers: ASTM E96/E96M-14 - Standard Test Methods for Water Vapor Transmission of Materials
• Effective Date: 15-Oct-2014

Overview

ASTM F2733-21 is the standard specification developed by ASTM International for flame-resistant rainwear designed to protect workers from flame hazards, specifically in environments where they may be exposed to both wet weather and industrial hydrocarbon or petrochemical fires. This specification establishes the critical minimum performance criteria for rainwear, detailing applicable test methods, physical and thermal performance requirements, and guidelines for proper sizing and purchasing. With a focus on safety and functional performance, ASTM F2733-21 is a cornerstone document for those selecting, procuring, or certifying flame-resistant (FR) rainwear used in hazardous work settings.

Key Topics

• Flame Resistance: The standard outlines minimum requirements for resistance to ignition, char length, and afterflame time, ensuring the rainwear minimizes burn injuries in fire incidents.
• Leak Resistance: Specifications address both material and seam leak resistance, ensuring protection against water ingress even under high-pressure conditions.
• Thermal Performance: Requirements are established for rainwear to withstand exposure to simulated fire conditions, including comprehensive testing protocols using instrumented manikins.
• Physical Durability: Standards for material weight, tear strength, and burst strength verify the durability and consistency of rainwear fabrics.
• Design and Construction: Guidelines for multiple-layer constructions, covered fasteners, and the use of heat-resistant closures are provided to improve overall safety.
• Labeling and Certification: Rainwear must be permanently labeled regarding size, manufacturer, and compliance to the ASTM F2733 specification.

Applications

ASTM F2733-21-compliant flame-resistant rainwear is essential for workers in industries where simultaneous exposure to rainfall and potential flash fire hazards exists. Typical applications include:

• Oil and Gas: Onshore and offshore platforms, refineries, and processing plants where hydrocarbon fires are a risk.
• Chemical Processing: Facilities handling volatile petrochemicals or flammable agents.
• Emergency Response: Firefighters and rescue personnel operating in environments where weather conditions and flash fire risks coincide.
• Industrial Maintenance: Utilities and service companies conducting outdoor maintenance in hazardous areas.

By adhering to ASTM F2733-21, employers and safety managers ensure their rainwear choices provide tested and proven protection, minimizing injury and meeting regulatory safety requirements. The standard can be referenced in purchasing contracts to guarantee rainwear products meet all specified minimum performance criteria.

Related Standards

The following standards are referenced within ASTM F2733-21 or serve complementary roles in the selection and use of flame-resistant rainwear:

• ASTM F1891: Specification for ARC and flame-resistant rainwear (specifically addresses electric arc flash hazards).
• NFPA 2112: Standard on flame-resistant garments for protection of industrial personnel against flash fire.
• ASTM D6413: Test method for vertical flame resistance of textiles.
• ASTM F1930: Test method for evaluating flame-resistant clothing using an instrumented manikin.
• AATCC 127: Method for water resistance: hydrostatic pressure test.
• ASTM D3393: Specification for waterproofness of coated fabrics.

Practical Value

With an emphasis on performance-based criteria rather than prescriptive material choices, ASTM F2733-21 allows manufacturers flexibility in design while ensuring end users benefit from verified levels of thermal and physical protection. This standard plays a vital role in workplace safety programs for high-risk industries, contributing to the reduction of burn injuries, improving worker confidence, and supporting regulatory compliance for flame-resistant personal protective equipment.

Keywords: ASTM F2733, flame-resistant rainwear, FR rainwear, hydrocarbon fire protection, petrochemical safety, PPE standards, industrial fire hazards, leak-resistant rainwear, thermal performance testing, protective clothing compliance.

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:F2733 −21
Standard Specification for
Flame-Resistant Rainwear for Protection Against Flame
Hazards
This standard is issued under the fixed designation F2733; 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 address all of the safety concerns, if any, associated with its
use. It is the responsibility of the user of this standard to
1.1 This specification establishes applicable test methods,
establish appropriate safety, health, and environmental prac-
minimum physical and thermal performance criteria, a sug-
tices and determine the applicability of regulatory limitations
gested sizing guide, and suggested purchasing information for
prior to use.
rainwear for use by workers who are potentially exposed to
1.8 This international standard was developed in accor-
industrial hydrocarbon fires or other petrochemical fire haz-
dance with internationally recognized principles on standard-
ards.
ization established in the Decision on Principles for the
1.1.1 This specification does not apply to rainwear used for
Development of International Standards, Guides and Recom-
thermal electric arc flash hazards. Specification of rainwear for
mendations issued by the World Trade Organization Technical
these electric arc flash hazards is addressed in Specification
Barriers to Trade (TBT) Committee.
F1891.
1.2 The objective of this specification is to prescribe func-
2. Referenced Documents
tion and performance criteria for rainwear that meets a mini-
2.1 ASTM Standards:
mum level of thermal and physical performance when exposed
D123 Terminology Relating to Textiles
to a laboratory-simulated fire exposure.
D751 Test Methods for Coated Fabrics
1.3 This specification is not intended to serve as a detailed
D1117 Guide for Evaluating Nonwoven Fabrics (Withdrawn
manufacturing or purchasing specification, but can be refer-
2009)
enced in purchase contracts to ensure that minimum perfor-
D1388 Test Method for Stiffness of Fabrics
mance requirements are met.
D3393 Specification for Coated Fabrics—Waterproofness
D3776/D3776M Test Methods for Mass Per Unit Area
1.4 Controlled laboratory tests used to determine compli-
(Weight) of Fabric
ance with the performance requirements of this specification
D3786/D3786M Test Method for Bursting Strength of Tex-
shall not be deemed as establishing performance levels for all
tile Fabrics—Diaphragm Bursting StrengthTester Method
situations to which wearers of this protective clothing are
D4391 Terminology Relating to The Burning Behavior of
potentially exposed.
Textiles
1.5 This specification does not attempt to establish in-
D6413/D6413M Test Method for Flame Resistance of Tex-
service care and use of this flame-resistant rainwear.
tiles (Vertical Test)
1.6 The values stated in SI units are to be regarded as
E96/E96M Test Methods for Water Vapor Transmission of
standard. The values given in parentheses are mathematical
Materials
conversions to inch-pound or other units that are commonly
F1494 Terminology Relating to Protective Clothing
used for thermal testing.
F1891 Specification for Arc and Flame Resistant Rainwear
F1930 Test Method for Evaluation of Flame-Resistant
1.7 The following safety hazards caveat pertains to Sections
Clothing for ProtectionAgainst Fire Simulations Using an
7 and 9 of this specification. This standard does not purport to
1 2
This specification is under the jurisdiction of ASTM Committee F23 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Personal Protective Clothing and Equipment and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee F23.80 on Flame and Thermal. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Feb. 1, 2021. Published February 2021. Originally the ASTM website.
approved in 2009. Last previous edition approved in 2017 as F2733 – 17. DOI: The last approved version of this historical standard is referenced on
10.1520/F2733-21. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2733−21
Instrumented Manikin 3.1.6 charring, n—the formation of carbonaceous residue as
the result of pyrolysis or incomplete combustion.
2.2 Federal Specifications:
FTMS 191A, Method 5516
3.1.7 design test, n—for flame-resistant rainwear, one made
FTMS CCC-T-191b, Method 5204
on a sample as representative of a commercial product; these
tests will not generally be repeated in quantity production.
2.3 AATCC Standards:
AATCC 135 Dimensional Changes Automatic Home Laun- 3.1.7.1 Discussion—Perform the design test only when a
dering of Woven and Knitted Fabrics new or modified rainwear material, substrate, coating, or
AATCC 127 Water Resistance: Hydrostatic Pressure Test adhesiveisusedtomanufacturerainwear.Achangeinrainwear
material includes, but is not limited to, any of the following:
2.4 NFPA Standard:
the material composition, weight, coating, laminate, adhesive,
NFPA 2112 Standard on Flame-Resistant Garments for Pro-
or the supplier of the material, substrate, coating, laminate, or
tection of Industrial Personnel Against Flash Fire, 2007
adhesive.
Edition
3.1.8 dripping, n—in testing thermal protective material, a
3. Terminology
response evidenced by flowing of the fiber polymer.
3.1.8.1 Discussion—In testing thermal protective materials,
3.1 Definitions:
coated fabrics, or laminates, dripping is a response evidenced
3.1.1 afterflame,n—persistentflamingofamaterialafterthe
byflowingofthefiberpolymer,thefabriccoating,orthefabric
ignition source has been removed.
laminates, and the evidence of droplets from the flowing
3.1.2 afterflame time, n—the length of time for which a
material.
material continues to flame after the ignition source has been
removed.
3.1.9 embrittlement, n—the formation of a brittle residue as
3.1.2.1 Discussion—Duringsimulatedlaboratoryfiretesting a result of pyrolysis or incomplete combustion.
of clothing, the length of time for which a specimen continues
3.1.10 fire exposure, n—in laboratory-simulated fire testing
to exhibit a visible flaming as determined by a time display
of clothing, a fuel-rich fire generated with non-stoichiometric
video recording or visual observation of the specimen during
amounts of propane and oxygen in air leading to incomplete
testing.
combustion of the propane. The fire exposure is a propane-air
3.1.3 breakopen, n—in testing thermal protective materials,
diffusion flame with a controlled heat flux engulfing the
a material response evidenced by the formation of a hole in the
manikin for a controlled duration.
test specimen during the thermal exposure that can result in
3.1.11 flame resistance, n—the property of a material
direct exposure to heat/flame.
whereby flaming combustion is prevented, terminated, or
3.1.3.1 Discussion—The specimen is considered to exhibit
inhibited following application of a flaming or nonflaming
breakopen when a hole is produced as a result of the thermal
source of ignition, with or without subsequent removal of the
2 2
exposure that is at least 3.2 cm (0.5 in. ) in area or at least
ignition source.
2.5 cm (1.0 in.) in any dimension. Single threads across the
3.1.12 garment ignition, n—in laboratory-simulated fire
opening or hole do not reduce the size of the hole for the
testing of clothing, the initiation of combustion of a garment
purposes of this test method.
specimen that does not self extinguish for at least 10 s.
3.1.4 burn injury, n—burn damage which occurs within
human skin at various depths as a function of temperature and 3.1.13 heat energy exposure, n—in laboratory-simulated
time and which can be described mathematically in a burn
fire testing of clothing, the total heat energy received at a
injury model.
surface as a direct result of a laboratory-simulated fire.
3.1.4.1 Discussion—Burn injury in human tissue occurs
3.1.13.1 Discussion—As related to heat energy exposure,
2 2
when the tissue is heated above a critical temperature. The
the energy in J/cm (cal/cm ), that is transferred to the material
degree of burn injury—first, second, or third degree—depends
surface is determined by multiplying the heat flux of the
upon the level above the critical temperature, the duration
laboratory-simulated flash fire by the duration of the
above the critical temperature, and the depth in the skin layers.
laboratory-simulated flash fire.
3.1.5 char length, n—in measuring flame resistance of
3.1.14 melting, n—a material response evidenced by soften-
textiles, the distance from the fabric edge which was directly
ing of the polymer.
exposed to the flame to the furthest point of visible fabric
3.1.14.1 Discussion—In testing flame-resistant rainwear,
damage after a specified tearing force has been applied.
melting is additionally defined as the liquefaction of material
under the influence of heat.
3.1.15 rainwear, n—a garment which provides protection
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
from precipitation for the head, limbs, and body of the user.
Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
www.dodssp.daps.mil.
5 3.1.16 shrinkage, n—a decrease in one or more dimensions
Available from American Association of Textile Chemists and Colorists
(AATCC), P.O. Box 12215, Research Triangle Park, NC 27709, http:// of an object or material.
www.aatcc.org.
3.1.17 thermal exposure, n—the intensity of heat energy to
Available from National Fire Protection Association (NFPA), 1 Batterymarch
Park, Quincy, MA 02169-7471, http://www.nfpa.org. which a fabric is exposed.
F2733−21
3.1.18 thermal material response, n—in laboratory- 5.1.10 Jacket length, trouser length (if applicable), trouser/
simulated fire testing of clothing, the effects that are observed jacket overlap (if applicable), and
concurrent and subsequent to thermal exposure, which can 5.1.11 Notation of conformance to this specification.
include phenomena such as breakopen, charring,
6. Materials and Manufacture
embrittlement, melting, shrinkage, etc.
6.1 The rainwear shall be designed and manufactured using
3.1.18.1 Discussion—The thermal material response is a
materials and seam constructions that meet the requirements
result of exposure to the radiant and convective energy of the
for leak resistance in 7.3.
laboratory-simulated fire.
6.2 Mechanical fastener closures, such as buttons or snaps,
3.1.19 thermalprotection,n—thepropertythatcharacterizes
shall be designed and constructed so that they are covered by
the overall performance of a garment or protective clothing
the rainwear outer layer material.
ensemble relative to how it retards thermal energy that is
6.2.1 This will result in the garment having a multiple layer
sufficient to cause a predicted second-degree or predicted
construction in the area of the closure. This will also prevent
third-degree burn injury.
the closure hardware from being directly exposed to the
3.1.19.1 Discussion—Thermal protection of a garment or
thermal hazard.
ensemble and the consequential predicted burn injury (second-
degree, third-degree, or both), are quantified from the response
NOTE 1—In limited testing, it has been found some uncovered closures
of manikin test thermal energy sensors. In addition to the melt and fuse. Constructing the closures so that they are covered as
described above is designed to mitigate the melting and fusing observed
calculated results, the physical response and degradation of the
with uncovered closures.
garment or protective ensemble are observable phenomena
useful in understanding garment or protective clothing en- 7. Physical Performance Testing Procedures
semble thermal protection.
7.1 Test rainwear material for physical performance charac-
3.1.20 thermal resistance, n—the reciprocal of thermal
teristics initially as manufactured or as received from the
transmittance.
manufacturer and after five cleaning and drying cycles unless
otherwise indicated.
3.1.21 thermal transmittance, n—unidirectional heat trans-
7.1.1 Clean and dry in accordance with care instructions
fer per unit area, in the steady state, between parallel planes,
from the rainwear manufacturer.
per unit difference of temperature of the planes.
7.1.1.1 If no cleaning instructions are provided by the
3.2 For definitions of other textile terms used in this
rainwear manufacturer, clean and dry in accordance with
specification, refer toTerminologies D123, D4391, and F1494.
AATCC Method 135 (3, IV A iii).
7.1.2 For limited-use or disposable rainwear with care
4. Significance and Use
instructionsindicatingtherainwearisnottobecleaned,testthe
4.1 This specification covers the minimum performance rainwear material sample only as received or as manufactured.
criteria for flame resistance and other requirements for rain-
7.2 Weight and Weight Uniformity – Rainwear Material:
2 2
wear used by workers with the potential to be simultaneously
7.2.1 Determine the average weight in g/m (oz/yd)ofthe
exposed to wet weather conditions and either hydrocarbon or
rainwear material sample submitted for the material testing in
petrochemical industrial fires.
7.3, 7.4, and 7.5 (optional) in accordance with Test Methods
D3776/D3776M, Option B. If a single sample of rainwear
4.2 The purchaser has the option to perform or have
material is used for all of the designated tests, one average
performed any of the tests required by this specification in
weight determination shall be done. If a different rainwear
order to verify the performance of the rainwear.
material sample is used for one or more of the tests, a separate
4.3 This specification for rainwear shall not be construed as
average weight determination shall be done for each rainwear
a requirement for the use of any particular rainwear material.
material sample.
7.2.1.1 Determine the average weight of each rainwear
5. Ordering Information
material sample initially as received and after five cleaning and
5.1 It is useful for the purchaser to consider the following
drying cycles as described in 7.1.
items when buying rainwear under this specification. Include
7.2.2 Determine weight uniformity across the width of the
these items, as necessary, in purchasing documents:
rainwear material sample as received using the same tempera-
5.1.1 Type of material,
tureandhumiditypreconditioningasrequiredforTestMethods
2 2
5.1.2 Fabric weight, g/m (oz/yd ),
D3776/D3776M, Option B.
5.1.3 Type and material of fasteners (buttons, snaps,
7.2.2.1 For each as-received rainwear material sample for
zippers, or hook-and-loop fasteners),
which the average weight was determined in accordance with
5.1.4 Reflective material sections (optional),
7.2.1, take five specimens, each consisting of a circle of
5.1.5 Style and design or catalog number,
rainwearmaterial89mm(3.5in.)indiameteratapproximately
5.1.6 Hood design (attached or detachable),
equal spaced intervals diagonally across the width of the
5.1.7 Sizes, rainwear material sample.
2 2
5.1.8 Color, 7.2.2.2 Determinetheweighting/m (oz/yd )ofeachofthe
5.1.9 Special identification markings (optional), five specimens.
F2733−21
7.3 Leak Resistance – Rainwear Material and Seams: 8.3.1.2 Alternatively, clean and dry the rainwear coverall
specimens in accordance with the procedure required by NFPA
7.3.1 Test the rainwear material in accordance with Speci-
2112.
fication D3393 at a water pressure of 207 kPa (30 psig).
8.3.2 For limited-use or disposable rainwear with care
7.3.2 Test the seams of the rainwear material in accordance
instructionsindicatingtherainwearisnottobecleaned,testthe
with AATCC 127 test method at a water pressure of 20.7 kPa
(3 psig) for 2 min. rainwear material sample only as received or as manufactured.
8.3.3 Dress theTest MethodF1930 instrumented manikin in
7.3.2.1 Use a pump device to achieve 20.7 kPa (3 psig) if
extension of the water column is not practical. 100 % cotton briefs and a 100 % cotton crew neck T-shirt
before the rainwear coverall specimens are positioned on the
7.4 Trapezoidal Tearing Resistance or Burst Strength:
instrumented manikin.
7.4.1 Test the rainwear material for trapezoidal tearing
2 2
8.3.4 Use a heat flux of 84 6 4 kW/m (2.0 6 0.1 cal/cm s)
resistance in accordance with Guide D1117, except that the
and an exposure time of 3 6 0.1 s as test parameters for Test
measured value shall be the average of the five highest peak
Method F1930. It is acceptable to assess additional test
loads. Appendix X3 provides detailed information for the
parameters and report the results on an optional basis.
trapezoidal tearing resistance of rainwear material in accor-
8.3.5 Determine the predicted total area of burn injury, the
dance with Guide D1117.
predicted second-degree burn area, and the predicted third-
7.4.2 When the rainwear substrate fabric is a knit or a
degree burn area in accordance with Test Method F1930,
stretch woven material, it is acceptable to substitute Test
subsections 12.5 and 12.6. Determine the averages of these
Method D3786/D3786M for the trapezoidal tearing resistance
parameters for the three Test Method F1930 tests.
test.
8.3.5.1 If more than three rainwear coverall specimens are
7.5 Water Vapor Transmission:
tested in accordance with 8.3, determine the test results and the
7.5.1 On an optional basis, test the rainwear material for
averages of test results listed in 8.3.5 for the total number of
water vapor transmission (WVT) in accordance with Test
specimens tested.
Methods E96/E96M using the inverted cup (BW) procedure.
8.4 ClosureFunctionandStructuralSeamIntegrity—Testat
least two sets of as-sold or finished goods rainwear subject to
8. Thermal Performance Testing Procedures
this standard in size “large” in accordance with Test Method
8.1 Rainwear samples for thermal tests shall be representa-
F1930. This testing shall apply to all models and styles of
tive of the rainwear material or system. If the rainwear is
rainwear from the rainwear manufacturer for which seams and
constructed of a single-layer material, carry out all thermal
closures of the tested as-sold or finished goods rainwear are
tests on a single-layer sample of the rainwear material. If the
representative.
rainwear is constructed of a multi-layer system of materials,
NOTE 3—A set of as-sold or finished goods rainwear can consist of a
test each layer of the multilayer system by the procedure in 8.2
jacket and pants, a jacket and bib overalls, or a coverall as long as the set
and test a multi-layer sample of the rainwear by the procedures
of rainwear is subject to this standard and is a style or model designed and
in 8.3 and 8.4.
manufactured as sold to users.
NOTE 4—Test Method F1930 is a design test.
8.2 Test the rainwear material for flame resistance in accor-
8.4.1 Test the as-sold rainwear by the procedure in 8.4 after
dance with Test Method D6413/D6413M.
one cleaning and drying. Clean and dry as directed by care
8.2.1 Test the rainwear material initially as manufactured or
instructions from the rainwear manufacturer.
as received from the manufacturer and after five cleaning and
drying cycles as described in 7.1. 8.4.1.1 If no cleaning instructions are provided by the
as-sold rainwear manufacturer, clean and dry the rainwear one
8.2.2 For limited-use or disposable rainwear with care
time in accordance with theAATCC Method 135 (3, IVAiii).
instructionsindicatingtherainwearisnottobecleaned,testthe
rainwearcoverallspecimensonlyasreceivedwithoutcleaning. 8.4.1.2 Alternatively, clean and dry the as-sold rainwear in
accordance with the procedure required by NFPA 2112.
8.3 Test at least three rainwear coverall specimens made
8.4.2 For limited-use or disposable as-sold rainwear with
from the rainwear material sample in accordance with Test
care instructions indicating the rainwear is not to be cleaned,
Method F1930. Fabricate the coverall specimens in accordance
test the rainwear only as received without cleaning.
with the standard garment requirements specified in Test
8.4.3 Dress theTest MethodF1930 instrumented manikin in
Method F1930, subsection 8.3.2.
100 % cotton briefs and a 100 % cotton crew neck T-shirt
NOTE 2—Test Method F1930 is a design test.
before the rainwear specimens are positioned on the instru-
mented manikin.
8.3.1 Test the three rainwear coverall specimens by the
2 2
procedure in 8.3 after one cleaning and drying. Clean and dry 8.4.4 Use a heat flux of 84 6 4 kW/m (2.0 6 0.1 cal/cm s)
the rainwear coverall specimens as directed by care instruc- and an exposure time of 3 6 0.1 s as test parameters for Test
tions from the rainwear manufacturer. Method F1930. It is acceptable to assess additional test
parameters and report the results on an optional basis.
8.3.1.1 If no cleaning instructions are provided by the
rainwear manufacturer, clean and dry the rainwear coverall 8.4.5 Determine the predicted total area of burn injury, the
specimens one time in accordance with the AATCC Method predicted second-degree burn area, and the predicted third-
135 (3, IV A iii). degree burn area according to Test Method F1930, subsections
F2733−21
12.5 and 12.6. Determine the averages of these parameters for 9.5.1 When tested by the procedure in 8.2, the average
the two Test Method F1930 tests. afterflame time shall not be more than 2 s after removal of the
ignition source for specimens in both the warp and fill
8.4.5.1 If more than two sets of rainwear are tested in
directions. The average char length shall be less than or equal
accordancewith8.4,determinethetestresultsandtheaverages
to 102 mm (4 in.) for specimens in both the warp and fill
of test results listed in 8.4.5 for the total number of sets of
directions. Specimens shall not melt and drip during testing.
rainwear tested.
Both melting and dripping must occur for a specimen to fail.
8.4.6 Structural Seam Integrity—Inspect structural seams of
An indication of melting by itself shall not be interpreted as
each of the sets of as-sold rainwear after the exposure in 8.4.4
melting and dripping.
and before removal of the rainwear from the manikin and also
before opening the rainwear closures. Determine any structural
9.6 Predicted Burn Injury Using Laboratory-Simulated Fire
seam failure
...

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: F2733 − 17 F2733 − 21
Standard Specification for
Flame-Resistant Rainwear for Protection Against Flame
Hazards
This standard is issued under the fixed designation F2733; 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 specification establishes applicable test methods, minimum physical and thermal performance criteria, a suggested sizing
guide, and suggested purchasing information for rainwear for use by workers who are potentially exposed to industrial hydrocarbon
fires or other petrochemical fire hazards.
1.1.1 This specification does not apply to rainwear used for thermal electric arc flash hazards. Specification of rainwear for these
electric arc flash hazards areis addressed in Specification F1891.
1.2 The objective of this specification is to prescribe function and performance criteria for rainwear that meets a minimum level
of thermal and physical performance when exposed to a laboratory-simulated fire exposure.
1.3 This specification is not intended to serve as a detailed manufacturing or purchasing specification, but can be referenced in
purchase contracts to ensure that minimum performance requirements are met.
1.4 Controlled laboratory tests used to determine compliance with the performance requirements of this specification shall not be
deemed as establishing performance levels for all situations to which wearers of this protective clothing are potentially exposed.
1.5 This specification does not attempt to establish in-service care and use of this flame-resistant rainwear.
1.6 The values stated in SI units are to be regarded as standard. The values given in bracketsparentheses are mathematical
conversions to inch-pound or other units that are commonly used for thermal testing.
1.7 The following safety hazards caveat pertains to Sections 7 and 9 of this specification. 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.
1.8 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.
This specification 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 Sept. 1, 2017Feb. 1, 2021. Published September 2017February 2021. Originally approved in 2009. Last previous edition approved in 20092017
as F2733 – 09.F2733 – 17. DOI: 10.1520/F2733-17.10.1520/F2733-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2733 − 21
2. Referenced Documents
2.1 ASTM Standards:
D123 Terminology Relating to Textiles
D751 Test Methods for Coated Fabrics
D1117 Guide for Evaluating Nonwoven Fabrics (Withdrawn 2009)
D1388 Test Method for Stiffness of Fabrics
D3393 Specification for Coated Fabrics—Waterproofness
D3776/D3776M Test Methods for Mass Per Unit Area (Weight) of Fabric
D3786/D3786M Test Method for Bursting Strength of Textile Fabrics—Diaphragm Bursting Strength Tester Method
D4391 Terminology Relating to The Burning Behavior of Textiles
D6413/D6413M Test Method for Flame Resistance of Textiles (Vertical Test)
E96/E96M Test Methods for Water Vapor Transmission of Materials
F1494 Terminology Relating to Protective Clothing
F1891 Specification for Arc and Flame Resistant Rainwear
F1930 Test Method for Evaluation of Flame-Resistant Clothing for Protection Against Fire Simulations Using an Instrumented
Manikin
2.2 Federal Specifications:
FTMS 191A, Method 5516
FTMS CCC-T-191b, Method 5204
2.3 AATCC Standards:
AATCC 135 Dimensional Changes Automatic Home Laundering of Woven and Knitted Fabrics
AATCC 127 Water Resistance: Hydrostatic Pressure Test
2.4 NFPA Standard:
NFPA 2112 Standard on Flame-Resistant Garments for Protection of Industrial Personnel Against Flash Fire, 2007 Edition
3. Terminology
3.1 Definitions:
3.1.1 afterflame, n—persistent flaming of a material after the ignition source has been removed.
3.1.2 afterflame time, n—the length of time for which a material continues to flame after the ignition source has been removed.
3.1.2.1 Discussion—
During simulated laboratory fire testing of clothing, the length of time for which a specimen continues to exhibit a visible flaming
as determined by a time display video recording or visual observation of the specimen during testing.
3.1.3 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 can result in direct exposure to heat/flame.
3.1.3.1 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 (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.
3.1.4 burn injury, n—burn damage which occurs within human skin at various depths as a function of temperature and time and
which can be described mathematically in a burn injury model.
3.1.4.1 Discussion—
Burn injury in human tissue occurs when the tissue is heated above a critical temperature. The degree of burn injury—first, second,
or third degree—depends upon the level above the critical temperature, the duration above the critical temperature, and the depth
in the skin layers.
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.
The last approved version of this historical standard is referenced on www.astm.org.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://www.dodssp.daps.mil.
Available from American Association of Textile Chemists and Colorists (AATCC), P.O. Box 12215, Research Triangle Park, NC 27709, http://www.aatcc.org.
Available from National Fire Protection Association (NFPA), 1 Batterymarch Park, Quincy, MA 02169-7471, http://www.nfpa.org.
F2733 − 21
3.1.5 char length, n—in measuring flame resistance of textiles, the distance from the fabric edge which was directly exposed to
the flame to the furthest point of visible fabric damage after a specified tearing force has been applied.
3.1.6 charring, n—the formation of carbonaceous residue as the result of pyrolysis or incomplete combustion.
3.1.7 design test, n—for flame-resistant rainwear, one made on a sample as representative of a commercial product; these tests will
not generally be repeated in quantity production.
3.1.7.1 Discussion—
Perform the design test only when a new or modified rainwear material, substrate, coating, or adhesive is used to manufacture
rainwear. A change in rainwear material includes, but is not limited to, any of the following: Thethe material composition, weight,
coating, laminate, adhesive, or the supplier of the material, substrate, coating, laminate, or adhesive.
3.1.8 dripping, n—in testing thermal protective material, a response evidenced by flowing of the fiber polymer.
3.1.8.1 Discussion—
In testing thermal protective materials, coated fabrics, or laminates, dripping is a response evidenced by flowing of the fiber
polymer, the fabric coating, or the fabric laminates, and the evidence of droplets from the flowing material.
3.1.9 embrittlement, n—the formation of a brittle residue as a result of pyrolysis or incomplete combustion.
3.1.10 fire exposure, n—in laboratory-simulated fire testing of clothing, a fuel rich fuel-rich fire generated with non-stoichiometric
amounts of propane and oxygen in air leading to incomplete combustion of the propane. The fire exposure is a propane-air diffusion
flame with a controlled heat flux engulfing the manikin for a controlled duration.
3.1.11 flame resistance, n—the property of a material whereby flaming combustion is prevented, terminated, or inhibited following
application of a flaming or nonflaming source of ignition, with or without subsequent removal of the ignition source.
3.1.12 garment ignition, n—in laboratory-simulated fire testing of clothing, the initiation of combustion of a garment specimen
that does not self extinguish for at least 10 s.
3.1.13 heat energy exposure, n—in laboratory-simulated fire testing of clothing, the total heat energy received at a surface as a
direct result of a laboratory-simulated fire.
3.1.13.1 Discussion—
2 2
As related to heat energy exposure, the energy in J/cm (cal/cm ), that is transferred to the material surface is determined by
multiplying the heat flux of the laboratory-simulated flash fire by the duration of the laboratory-simulated flash fire.
3.1.14 melting, n—a material response evidenced by softening of the polymer.
3.1.14.1 Discussion—
In testing flame-resistant rainwear, melting is additionally defined as the liquefaction of material under the influence of heat.
3.1.15 rainwear, n—a garment which provides protection from precipitation for the head, limbs, and body of the user.
3.1.16 shrinkage, n—a decrease in one or more dimensions of an object or material.
3.1.17 thermal exposure, n—the intensity of heat energy to which a fabric is exposed.
3.1.18 thermal material response, n—in laboratory-simulated fire testing of clothing, the effects that are observed concurrent and
subsequent to thermal exposure, which can include phenomena such as breakopen, charring, embrittlement, melting, shrinkage, etc.
3.1.18.1 Discussion—
The thermal material response is a result of exposure to the radiant and convective energy of the laboratory-simulated fire.
3.1.19 thermal protection, n—the property that characterizes the overall performance of a garment or protective clothing ensemble
relative to its ability to reduce burn injury caused by heat transfer.how it retards thermal energy that is sufficient to cause a predicted
second-degree or predicted third-degree burn injury.
F2733 − 21
3.1.19.1 Discussion—
Thermal protection of a garment or ensemble and the consequential predicted burn injury (second-degree, third-degree, or both),
are quantified from the response of manikin test thermal energy sensors. In addition to the calculated results, the physical response
and degradation of the garment or protective ensemble are observable phenomena useful in understanding garment or protective
clothing ensemble thermal protection.
3.1.20 thermal resistance, n—the reciprocal of thermal transmittance.
3.1.21 thermal transmittance, n—unidirectional heat transfer per unit area, in the steady state, between parallel planes, per unit
difference of temperature of the planes.
3.2 For definitions of other textile terms used in this specification, refer to Terminologies D123, D4391, and F1494.
4. Significance and Use
4.1 This specification covers the minimum performance criteria for flame resistance and other requirements for rainwear used by
workers with the potential to be simultaneously exposed to wet weather conditions and either hydrocarbon or petrochemical
industrial fires.
4.2 The purchaser has the option to perform or have performed any of the tests required by this specification in order to verify
the performance of the rainwear.
4.3 This specification for rainwear shall not be construed as a requirement for the use of any particular rainwear material.
5. Ordering Information
5.1 It is useful for the purchaser to consider the following items when buying rainwear under this specification. Include these
items, as necessary, in purchasing documents:
5.1.1 Type of material,
2 2
5.1.2 Fabric weight, g/m (oz/yd ),
5.1.3 Type and material of fasteners (buttons, snaps, zippers, or hook-and-loop fasteners),
5.1.4 Reflective material sections (optional),
5.1.5 Style and design or catalog number,
5.1.6 Hood design (attached or detachable),
5.1.7 Sizes,
5.1.8 Color,
5.1.9 Special identification markings (optional),
5.1.10 Jacket length, trouser length (if applicable), trouser/jacket overlap (if applicable), and
5.1.11 Notation of conformance to this specification.
6. Materials and Manufacture
6.1 The rainwear shall be designed and manufactured using materials and seam constructions that meet the requirements for leak
resistance in 7.3.
F2733 − 21
6.2 Mechanical fastener closures, such as buttons or snaps, shall be designed and constructed so that they are covered by the
rainwear outer layer material.
6.2.1 This will result in the garment having a multiple layer construction in the area of the closure. This will also prevent the
closure hardware from being directly exposed to the thermal hazard.
NOTE 1—In limited testing, it has been found some uncovered closures melt and fuse. Constructing the closures so that they are covered as described above
is designed to mitigate the melting and fusing observed with uncovered closures.
7. Physical Performance Testing Procedures
7.1 Test rainwear material for physical performance characteristics initially as manufactured or as received from the manufacturer
and after five cleaning and drying cycles unless otherwise indicated.
7.1.1 Clean and dry in accordance with care instructions from the rainwear manufacturer.
7.1.1.1 If no cleaning instructions are provided by the rainwear manufacturer, clean and dry in accordance with AATCC Method
135 (3, IV A iii).
7.1.2 For limited-use or disposable rainwear with care instructions indicating the rainwear is not to be cleaned, test the rainwear
material sample only as received or as manufactured.
7.2 Weight and Weight Uniformity – Rainwear Material:
2 2
7.2.1 Determine the average weight in g/m (oz/yd ) of the rainwear material sample submitted for the material testing in 7.3, 7.4,
and 7.5 (optional) in accordance with Test Methods D3776/D3776M, Option B. If a single sample of rainwear material is used for
all of the designated tests, one average weight determination shall be done. If a different rainwear material sample is used for one
or more of the tests, a separate average weight determination shall be done for each rainwear material sample.
7.2.1.1 Determine the average weight of each rainwear material sample initially as received and after five cleaning and drying
cycles as described in 7.1.
7.2.2 Determine weight uniformity across the width of the rainwear material sample as received using the same temperature and
humidity preconditioning as required for Test Methods D3776/D3776M, Option B.
7.2.2.1 For each as-received rainwear material sample for which the average weight was determined in accordance with 7.2.1, take
five specimens, each consisting of a circle of rainwear material 89 mm (3.5 in.) in diameter at approximately equal spaced intervals
diagonally across the width of the rainwear material sample.
2 2
7.2.2.2 Determine the weight in g/m (oz/yd ) of each of the five specimens.
F2733 − 21
7.3 Leak Resistance – Rainwear Material and Seams:
7.3.1 Test the rainwear material in accordance with Specification D3393 at a water pressure of 207 kPa (30 psig).
7.3.2 Test the seams of the rainwear material in accordance with AATCC 127 test method at a water pressure of 20.7 kPa (3 psig)
for 2 min.
7.3.2.1 Use a pump device to achieve 20.7 kPa (3 psig) if extension of the water column is not practical.
7.4 Trapezoidal Tearing Resistance or Burst Strength:
7.4.1 Test the rainwear material for trapezoidal tearing resistance in accordance with Guide D1117, except that the measured value
shall be the average of the five highest peak loads. Appendix X3 provides detailed information for the trapezoidal tearing resistance
of rainwear material in accordance with Guide D1117.
7.4.2 When the rainwear substrate fabric is a knit or a stretch woven material, it is acceptable to substitute Test Method
D3786/D3786M for the trapezoidal tearing resistance test.
7.5 Water Vapor Transmission:
7.5.1 On an optional basis, test the rainwear material for water vapor transmission (WVT) in accordance with Test Methods
E96/E96M using the inverted cup (BW) procedure.
8. Thermal Performance Testing Procedures
8.1 Rainwear samples for thermal tests shall be representative of the rainwear material or system. If the rainwear is constructed
of a single-layer material, carry out all thermal tests on a single-layer sample of the rainwear material. If the rainwear is constructed
of a multi-layer system of materials, test each layer of the multilayer system by the procedure in 8.2 and test a multi-layer sample
of the rainwear by the procedures in 8.3 and 8.4.
8.2 Test the rainwear material for flame resistance in accordance with Test Method D6413/D6413M.
8.2.1 Test the rainwear material initially as manufactured or as received from the manufacturer and after five cleaning and drying
cycles as described in 7.1.
8.2.2 For limited-use or disposable rainwear with care instructions indicating the rainwear is not to be cleaned, test the rainwear
coverall specimens only as received without cleaning.
8.3 Test at least three rainwear coverall specimens made from the rainwear material sample in accordance with Test Method
F1930. Fabricate the coverall specimens in accordance with the standard garment requirements specified in Test Method F1930,
subsection 8.3.2.
NOTE 2—Test Method F1930 is a design test.
8.3.1 Test the three rainwear coverall specimens by the procedure in 8.3 after one cleaning and drying. Clean and dry the rainwear
coverall specimens as directed by care instructions from the rainwear manufacturer.
8.3.1.1 If no cleaning instructions are provided by the rainwear manufacturer, clean and dry the rainwear coverall specimens one
time in accordance with the AATCC Method 135 (3, IV A iii).
8.3.1.2 Alternatively, clean and dry the rainwear coverall specimens in accordance with the procedure required by NFPA 2112.
8.3.2 For limited-use or disposable rainwear with care instructions indicating the rainwear is not to be cleaned, test the rainwear
material sample only as received or as manufactured.
F2733 − 21
8.3.3 Dress the Test Method F1930 instrumented manikin in 100 % cotton briefs and a 100 % cotton crew neck T-shirt before the
rainwear coverall specimens are positioned on the instrumented manikin.
2 2
8.3.4 Use a heat flux of 84 6 4 kW/m (2.0 6 0.1 cal/cm s) and an exposure time of 3 6 0.1 s as test parameters for Test Method
F1930. It is acceptable to assess additional test parameters and report the results on an optional basis.
8.3.5 Determine the predicted total area of burn injury, the predicted second-degree burn area, and the predicted third-degree burn
area in accordance with Test Method F1930, subsections 12.5 and 12.6. Determine the averages of these parameters for the three
Test Method F1930 tests.
8.3.5.1 If more than three rainwear coverall specimens are tested in accordance with 8.3, determine the test results and the
averages of test results listed in 8.3.5 for the total number of specimens tested.
8.4 Closure Function and Structural Seam Integrity—Test at least two sets of as-sold or finished goods rainwear subject to this
standard in size “large” in accordance with Test Method F1930. This testing shall apply to all models and styles of rainwear from
the rainwear manufacturer for which seams and closures of the tested as-sold or finished goods rainwear are representative.
NOTE 3—A set of as-sold or finished goods rainwear can consist of a jacket and pants, a jacket and bib overalls, or a coverall as long as the set of rainwear
is subject to this standard and is a style or model designed and manufactured as sold to users.
NOTE 4—Test Method F1930 is a design test.
8.4.1 Test the as-sold rainwear by the procedure in 8.4 after one cleaning and drying. Clean and dry as directed by care instructions
from the rainwear manufacturer.
8.4.1.1 If no cleaning instructions are provided by the as-sold rainwear manufacturer, clean and dry the rainwear one time in
accordance with the AATCC Method 135 (3, IV A iii).
8.4.1.2 Alternatively, clean and dry the as-sold rainwear in accordance with the procedure required by NFPA 2112.
8.4.2 For limited-use or disposable as-sold rainwear with care instructions indicating the rainwear is not to be cleaned, test the
rainwear only as received without cleaning.
8.4.3 Dress the Test Method F1930 instrumented manikin in 100 % cotton briefs and a 100 % cotton crew neck T-shirt before the
rainwear specimens are positioned on the instrumented manikin.
2 2
8.4.4 Use a heat flux of 84 6 4 kW/m (2.0 6 0.1 cal/cm s) and an exposure time of 3 6 0.1 s as test parameters for Test Method
F1930. It is acceptable to assess additional test parameters and report the results on an optional basis.
8.4.5 Determine the predicted total area of burn injury, the predicted second-degree burn area, and the predicted third-degree burn
area according to Test Method F1930, subsections 12.5 and 12.6. Determine the averages of these parameters for the two Test
Method F1930 tests.
8.4.5.1 If more than two sets of rainwear are tested in accordance with 8.4, determine the test results and the averages of test results
listed in 8.4.5 for the total number of sets of rainwear tested.
8.4.6 Structural Seam Integrity—Inspect structural seams of each of the sets of as-sold rainwear after the exposure in 8.4.4 and
before removal of the rainwear from the manikin and also before opening the rainwear closures. Determine any structural seam
failure which results in a structural seam opening that exceeds 51 mm (2 in.).
8.4.7 Closure Function After Thermal Exposure—For each of the sets of as-sold rainwear, after the exposure in 8.4.4 and before
removal of the rainwear specimen from the manikin, determine whether or not all rainwear closures can be fully opened, using
hands only.
9. Performance Requirements
9.1 Material Weight and Weight Uniformity:
F2733 − 21
9.1.1 Report the supplier’
...