Designation: C 1166 – 00

Standard Test Method for

Flame Propagation of Dense and Cellular Elastomeric
Gaskets and Accessories1
This standard is issued under the fixed designation C 1166; 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 (e) indicates an editorial change since the last revision or reapproval.

1. Scope 3. Terminology
1.1 This test method covers a laboratory procedure for 3.1 Definitions—For definitions of the terms: cellular mate-
determining flame propagation characteristics of a dense or rial, compound, compression gasket, elastomer, elastomeric,
cellular elastomeric gasket (such as expansion, lock-strip or expansion gasket, gasket, lock-strip gasket, setting block, shim
compression gasket) or an accessory (such as a setting block, spacer, and spacer and for the definitions of other terms used in
spacer or shim) when exposed to heat and flame, with no this standard, see Terminology C 717.
significance being attached to such matters as fuel contribution, 3.2 Definitions of Terms Specific to This Standard:
rate of flame spread, smoke developed, or the nature and 3.2.1 dense material, n—material that is free of porosity, as
temperature of the products of combustion. described in Specification C 864.
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are provided for 4. Summary of Test Method
information purposes only. 4.1 In this test method, a specimen 13 by 25 by 460 mm (1⁄2
1.3 This standard should be used to measure and describe by 1 by 18 in.) mounted in a vertical position within the test
the response of materials, products, or assemblies to heat and chamber, is exposed to a gas flame at the lower end for 15 min
flame under controlled conditions and should not be used to with dense materials or 5 min with cellular materials, and
describe or appraise the fire-hazard or fire-risk of materials, ventilated at no more than 18.3 m/min (60 ft/min). The length
products, or assemblies under actual fire conditions. However, of the flame is measured and provides a numerical value for the
results of the test may be used as elements of a fire-hazard propagation of flame along the specimen.
assessment or a fire-risk assessment which takes into account
all of the factors which are pertinent to an assessment of the 5. Significance and Use
fire hazard or fire risk of a particular end use. 5.1 This test method is designed to differentiate the flame
1.4 This standard does not purport to address all of the propagation characteristics of dense or cellular elastomeric
safety concerns, if any, associated with its use. It is the compounds used in gaskets, setting blocks, shims, or spacers.
responsibility of the user of this standard to establish appro- It is a small scale test which enables the specifier to exercise
priate safety and health practices and determine the applica- engineering judgment in the selection of materials.
bility of regulatory limitations prior to use. 5.2 In this test method, the specimens are subjected to a
specific laboratory fire test exposure condition. If different test
2. Referenced Documents conditions are substituted or the anticipated end-use conditions
2.1 ASTM Standards: are changed, it may not be possible by or from this test method
C 717 Terminology of Building Seals and Sealants2 to predict changes in the performance characteristics. There-
C 864 Specification for Dense Elastomeric Compression fore, the results are valid only for the fire test exposure
Seal Gaskets, Setting Blocks, and Spacers2 condition described in this test method.
D 3182 Practice for Rubber—Materials, Equipment and 5.3 If the results obtained by this test method are to be
Procedures for Mixing Standard Compounds and Prepar- considered in the total assessment of fire risk, then all pertinent
ing Standard Vulcanized Sheets3 established criteria for fire risk assessment developed by
ASTM Committee E-5 must be included in the consideration.

1
6. Comparison to Other Standards
This test method is under the jurisdiction of ASTM Committee C-24 on
Building Seals and Sealants and is the direct responsibility of Subcommittee C24.73 6.1 The ASTM Committee with jurisdiction over this stan-
on Compression Seal and Lock Strip Gaskets. dard1 is not aware of any comparable standards published by
Current edition approved Jan. 10, 2000. Published March 2000. Originally other organizations.
published as C 1166 – 91. Last previous edition C 1166 – 91 (1995).
2
Annual Book of ASTM Standards, Vol 04.07.
3
Annual Book of ASTM Standards, Vol 09.01.

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

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 C 1166
7. Apparatus approximately 38 mm (1.5 in.) high. A metal flame gage is
7.1 The Test Chamber, may be any enclosure that will recommended for a consistent height.
permit circulation of air past the specimen during burning. A 10.4 Place the lighted burner directly below the specimen so
hood or ventilated spray booth is recommended to remove any that the top of the inner cone of the flame just touches the
noxious products of combustion, provided the velocity of air lowest part of the specimen (see Note 3). The burner is to
past the specimen does not exceed 18.3 m/min (60 ft/min). remain in this position for 15 min and 5 min respectively for
dense and cellular material dictates, and then shall be extin-
NOTE 1—Air velocities greater than 18.3 m/min (60 ft/min) will have guished and removed. If the specimen moves through heat
an extinguishing effect upon the flame and will present an unrealistic
deformation, the burner needs to be moved so as to keep it
evaluation of the flame propagation of the compound.
under the lowest point of the specimen for the given test time.
7.2 Bunsen Burner, with a barrel nominally 9.5 mm (0.38
in.) in diameter. NOTE 3—Every flame, no matter how hot, has a kindling height above
which its temperature is too low to kindle the specimen. For the specified
7.3 Natural Gas, used for fuel.
flame, this height is considerably less than 460 mm (18 in.). Therefore, if
7.4 Measuring Device, capable of measuring to 0.1 in. a specimen burns above this kindling height, it does so on its own heat of
combustion and is considered to propagate flame.
8. Sampling and Test Specimens
8.1 Sampling: 10.5 Permit the specimen to continue burning until it no
8.1.1 When the finished product does not lend itself to longer propagates flame.
testing (see Note 2) or to the taking of test specimens because 10.6 After flame has extinguished, quench specimen with
of complicated shape, small size, metal or fabric inserts or water (even though specimen may still be glowing).
other conditions, standard test strips shall be prepared. The 10.7 Remove loose chart with a stiff brush.
standard specimens for testing are described in 8.2. 10.8 Measure the remaining unburned length of the speci-
men. Consider the unburned length to be that remaining after
NOTE 2—A chimney effect caused by lengthwise channels or holes in the removal of loose elastomer char that no longer can perform
finished products makes it impossible to obtain uniform results using for intended use. This may be uneven, and therefore requires
actual manufactured products.
two measurements
8.1.2 When possible, the completed manufactured product,
or a suitable section thereof shall be used for the test. 11. Calculation
Representative samples of the batch extrusions being examined 11.1 Calculate the average flame propagation (FP) for R1
shall be selected at random as required. through R6 according to the following equation:
8.2 Test Specimens: ([R1o − R1f] + [R2o − R2f] + [R3o − R3f]
8.2.1 The test specimen shall be 13 mm (1⁄2 in.) thick, 25
1 @R4o 2 R4f# 1 @R5o 2 R5f# 1 @R6o 2 R6f#!
mm (1 in.) wide and 460 mm (18 in.) long, made in accordance FP 5 6 (1)
with 8.1.
8.2.2 The test specimen shall be free of permanent set where:
producing a curved section within the specimen that will not R1o 5 original R1,
permit it to hang vertically. It shall also be free of abnormally R1f 5 final R1,
porous sections and foreign materials. R2o 5 original R2,
8.2.3 All test specimens shall be made from the same R2f 5 final R2, etc.
compound, same dated batch, and shall have the same apparent
12. Report
density and state of cure as the product they represent.
8.2.4 This test method requires six test specimens that have 12.1 Include the following information:
been cut randomly from the same extrusion labeled R1 through 12.1.1 Identification of each specimen, R1 through R6,
R6. 12.1.2 The original length of each test specimen,
12.1.3 The average of two measurements resulting from an
9. Conditioning uneven burn,
9.1 Condition all test specimens at 23.9 6 1.1°C (75 6 5°F) 12.1.4 A statement as to whether the sample melted, burned,
for at least 24 h prior to testing. propagated fire through burning droplets, or other method of
deterioration, and
10. Procedure 12.1.5 Variation, if any, from the specified test procedure.
10.1 Measure the original length of all test specimens.
10.2 Secure the specimen in a vertical position within the 13. Precision and Bias 4
test chamber using a ring stand with a clamp positioned at the 13.1 Precision:
top of the specimen. Locate the specimen high enough to 13.1.1 Repeatability (within a given laboratory)—The in-
permit the burner to be placed beneath it. Use two wire loops terval for four materials tested by four recognized fire testing
to retain the position of the sample over the flame. Place one laboratories was 0.85 in., 4.7 %. In future use of this test
wire loop 51 mm (2 in.) from the end to be ignited and the method, the difference between two results (defined as the
other 127 mm (5 in.) from the end to be ignited. Fasten the wire
loops to the stand holding the specimen.
10.3 Light and adjust the burner to produce a blue flame 4
Supporting data is available from ASTM Headquarters. Request RR: C24-1029.

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 C 1166
average of six individual results) obtained in the same labora- (defined as the average of six individual results) obtained in
tory on the same material will be expected to exceed 0.85 in., different laboratories on the same material will be expected to
4.7 % of original, only 5 % of the time. exceed 1.3 in. only 5 % of the time.
13.1.2 Reproducibility (between laboratories)—The inter-
val for four materials tested by four recognized fire testing 14. Keywords
laboratories is 1.3 in., 7.2 % of original length. In future use of
this test method, the difference between two test results 14.1 elastomer; flame propagation; flammability; gasket

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