ASTM E1995-98

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An American National Standard
Designation: E 1995 – 98
Standard Test Method for
Measurement of Smoke Obscuration Using a Conical
Radiant Source in a Single Closed Chamber, With the Test
Specimen Oriented Horizontally
This standard is issued under the fixed designation E 1995; 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 shall be employed in conducting these tests. This test method
may involve hazardous materials, operations, and equipment.
1.1 This is a fire-test-response standard.
See also 6.2.1.2, Section 7, and 11.7.2.
1.2 This test method provides a means of measuring smoke
1.10 This standard does not purport to address all of the
obscuration resulting from subjecting essentially flat materials,
safety concerns, if any, associated with its use. It is the
products, or assemblies (including surface finishes), not ex-
responsibility of the user of this standard to establish appro-
ceeding 25 mm (1 in.) in thickness, in a horizontal orientation,
priate safety and health practices and determine the applica-
exposed to specified levels of thermal irradiance, from a
bility of regulatory limitations prior to use.
conical heater, in the presence of a pilot flame, in a single
closed chamber. Optional testing modes exclude the pilot
2. Referenced Documents
flame.
2.1 ASTM Standards:
1.3 The principal fire-test-response characteristic obtained
D 2843 Test Method for Density of Smoke from the Burn-
from this test method is the specific optical density of smoke
ing or Decomposition of Plastics
from the specimens tested, which is obtained as a function of
D 4100 Test Method for Gravimetric Determination of
time, for a period of 10 min.
Smoke Particulates from Combustion of Plastic Materials
1.4 An optional fire-test-response characteristic measurable
D 5424 Test Method for Smoke Obscuration of Insulating
with this test method is the mass optical density (see Annex
Materials Contained in Electrical or Optical Fiber Cables
A1), which is the specific optical density of smoke divided by
When Burning in a Vertical Cable Tray Configuration
the mass lost by the specimens during the test.
E 84 Test Method for Surface Burning Characteristics of
1.5 The fire-test-response characteristics obtained from this
Building Materials
test are specific to the specimen tested, in the form and
E 176 Terminology of Fire Standards
thickness tested, and are not an inherent property of the
E 380 Practice for Use of the International System of Units
material, product, or assembly.
(SI) (the Modernized Metric System)
1.6 This test method does not provide information on the
E 603 Guide for Room Fire Experiments
fire performance of the test specimens under fire conditions
E 662 Test Method for Specific Optical Density of Smoke
other than those conditions specified in this test method. For
Generated by Solid Materials
limitations of this test method, see 5.5.
E 906 Test Method for Heat and Visible Smoke Release
1.7 Use the SI system of units in referee decisions; see
Rates for Materials and Products
Practice E 380. The inch-pound units given in parentheses are
E 1354 Test Method for Heat and Visible Smoke Release
for information only.
Rates for Materials and Products Using an Oxygen Con-
1.8 This test method is used to measure and describe the
sumption Calorimeter
response of materials, products, or assemblies to heat and
E 1474 Test Method for Determining the Heat Release Rate
flame under controlled conditions, but does not by itself
of Upholstered Furniture and Mattress Components or
incorporate all factors required for fire hazard or fire risk
Composites Using a Bench Scale Oxygen Consumption
assessment of the materials, products, or assemblies under
Calorimeter
actual fire conditions.
E 1537 Test Method for Fire Testing of Upholstered Furni-
1.9 Fire testing of products and materials is inherently
ture Items
hazardous, and adequate safeguards for personnel and property
This test method is under the jurisdiction of ASTM Committee E-5 on Fire 2
Annual Book of ASTM Standards, Vol 08.02.
Standards and is the direct responsibility of Subcommittee E05.21 on Smoke and 3
Annual Book of ASTM Standards, Vol 10.02.
Combustion Products. 4
Annual Book of ASTM Standards, Vol 4.07.
Current edition approved Dec. 10, 1998. Published March 1999. 5
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E1995–98
E 1590 Test Method for Fire Testing of Mattresses 3.2.13 time to ignition, n—time between the start of the test
2.2 ISO Standards: and the presence of a flame on the specimen surface for a
ISO Guide 52—Glossary of Fire Terms and Definitions period of at least 4s.
ISO 3261 Fire Tests–Vocabulary
4. Summary of Test Method
ISO 5659-2 Determination of Specific Optical Density by a
4.1 This test method assesses the reduction of light by
Single-Chamber Test
smoke obscuration from a burning sample. The test method
ISO 5725 Precision of Test Methods—Determination of
employs a conically-shaped, electrically-heated, radiant-energy
Repeatability and Reproducibility for Standard Test
source to produce irradiance levels of 25 and 50 kW/m ,
Method by Interlaboratory Tests
averaged over the center of the exposed surface of an essen-
2.3 British Standards:
tially flat specimen, and mounted horizontally inside a closed
BS 6809 Method of Calibration of Radiometers for Use in
chamber. The equipment is suitable for testing at irradiance
Fire Testing
levels of up to 50 kW/m .
3. Terminology 4.2 The specimen is 75 by 75 mm (3 by 3 in.), at a thickness
not exceeding 25 mm (1 in.) and is mounted horizontally
3.1 Definitions—For definitions of terms used in this test
within a holder.
method, refer to Terminology E 176 and ISO 3261. In case of
4.3 The exposure is conducted in the presence or in the
conflict, the definitions given in Terminology E 176 shall
absence of a pilot flame (see details in 6.3.6). If a pilot flame
prevail.
is used for ignition, the test is deemed to be in the “flaming”
3.2 Definitions of Terms Specific to This Standard:
mode; if a pilot flame is not used, the test is deemed to be in the
3.2.1 assembly, n—a unit or structure composed of a com-
“nonflaming” mode.
bination of materials or products, or both.
4.4 The test specimens are exposed to flaming or nonflam-
3.2.2 composite, n—a combination of materials, which
ing conditions within a closed chamber. A photometric system
generally are recognized as distinct entities, for example coated
with a vertical light path is used to measure the varying light
or laminated materials.
transmission as smoke accumulates. The light transmittance
3.2.3 continuous (as related to data acquisition), adj—
measurements are used to calculate the specific optical density
conducted at data collection intervals of 5s or less.
of the smoke generated during the test.
3.2.4 essentially flat surface, n—surface where the irregu-
4.5 The specimens are exposed to two conditions, out of the
larity from a plane does not exceed 6 1 mm.
four standard exposure conditions, to be chosen by the test
3.2.5 exposed surface, n—that surface of the specimen
requester. The four standard exposure conditions are: flaming
subjected to the incident heat.
mode at an irradiance of 25 kW/m , flaming mode at an
3.2.6 flaming mode, n—the mode of testing that uses a pilot
irradiance of 50 kW/m ; nonflaming mode at an irradiance of
flame.
25 kW/m ; and, nonflaming mode at an irradiance of 50
3.2.7 ignition, n—the initiation of combustion.
kW/m . Unless specified otherwise, conduct testing in the two
3.2.7.1 Discussion—The combustion may be evidenced by
flaming mode exposure conditions (see 8.3, X1.3 and X1.4).
glow, flame, detonation, or explosion. The combustion may be
Exposures to other irradiances also are possible.
sustained or transient.
4.6 Mass optical density is an optional fire-test-response
3.2.8 mass optical density, n—the ratio of the optical
characteristic obtainable from this test method, by using a load
density of smoke and the mass loss of the test specimen,
cell, which continuously monitors the mass of the test speci-
multiplied by the volume of the test chamber and divided by
men (see Annex A1).
the length of the light path.
3.2.8.1 Discussion—The mass optical density as determined
5. Significance and Use
in this test method is not an intrinsic material property; it is a
5.1 This test method provides a means for determining the
function of the test procedure and conditions used.
specific optical density of the smoke generated by specimens of
3.2.9 Nonflaming mode, n—the mode of testing that does
materials, products, or assemblies under the specified exposure
not use a pilot flame.
conditions. Values determined by this test are specific to the
3.2.10 sample, n—an amount of the material, product, or
specimen in the form and thickness tested and are not inherent
assembly, to be tested, which is representative of the item as a
fundamental properties of the material, product, or assembly
whole.
tested.
3.2.11 smoke obscuration, n—the reduction in visibility due
5.2 This test method uses a photometric scale to measure
to smoke (ISO Guide 52).
smoke obscuration, which is similar to the optical density scale
3.2.12 specimen, n—the actual section of material, product,
for human vision. The test method does not measure physi-
or assembly, to be placed in the test apparatus.
ological aspects associated with vision.
5.3 At the present time no basis exists for predicting the
smoke obscuration to be generated by the specimens upon
Available from International Standardization Organization, P.O. Box 56,
exposure to heat or flame under any fire conditions other than
CH-1211; Geneva 20, Switzerland, or from American National Standards Institute,
those specified. Moreover, as with many smoke obscuration
11 West 42nd, Street, New York, NY, 10046.
test methods, the correlation with measurements by other test
Available from British Standards Institution, P.O. Box 4033, Linford Wood,
Milton Keynes, MK14 6LE, United Kingdom. methods has not been established.
E1995–98
5.4 The current smoke density chamber test, Test Method test conditions are substituted or the end-use conditions are
E 662, is used by specifiers of floor coverings and in the rail changed, it is not necessarily possible by or from this test
transportation industries. The measurement of smoke obscura- method to predict changes in the fire-test-response character-
tion is important to the researcher and the product development istics measured; therefore, the results are valid only for the fire
scientist. This test method, which incorporates improvements test exposure conditions described in this procedure.
over Test Method E 662, also will increase the usefulness of 5.5.8 This test method solves some limitations associated
smoke obscuration measurements to the specifier and to with other closed chamber test methods, such as Test Method
product manufacturers. E 662 [2-5] (see 5.4.1). The test method retains some limita-
5.4.1 The following are improvements offered by this test tions related to closed chamber tests, as detailed in 5.5.8.1-
method over Test Method E 662: the horizontal specimen 5.5.8.5.
orientation solves the problem of melting and flaming drips 5.5.8.1 Information relating the specific optical density
from vertically oriented specimens; the conical heat source obtained by this test method to the mass lost by the specimen
provides a more uniform heat input; the heat input can be during the test is possible only by using the (optional) load cell,
varied over a range of up to 50 kW/m , rather than having a to determine the mass optical density (see Annex A1).
fixed value of 25 kW/m ; and, the (optional) load cell permits 5.5.8.2 All specimens consume oxygen when combusted.
calculations to be made of mass optical density, which associ- The smoke generation of some specimens (especially those
ates the smoke obscuration fire-test-response characteristic undergoing rapid combustion and those which are heavy and
measured with the mass loss. multilayered) is influenced by the oxygen concentration in the
5.5 Limitations : chamber. Thus, if the atmosphere inside the chamber becomes
5.5.1 The following behavior during a test renders that test oxygen-deficient before the end of the experiment, combustion
invalid: a specimen being displaced from the zone of controlled may ceases for some specimens; therefore, it is possible that
irradiance so as to touch the pilot burner or the pilot flame; those layers furthest away from the radiant source will not
extinction of the pilot flame (even for a short period of time) in undergo combustion.
the flaming mode; molten material overflowing the specimen 5.5.8.3 The presence of walls causes losses through depo-
holder; or, self-ignition in the nonflaming mode. sition of combustion particulates.
5.5.2 As is usual in small-scale test methods, results ob- 5.5.8.4 Soot and other solid or liquid combustion products
tained from this test method have proven to be affected by settle on the optical surfaces during a test, resulting in
variations in specimen geometry, surface orientation, thickness potentially higher smoke density measurements than those due
(either overall or individual layer), mass, and composition. to the smoke in suspension.
5.5.3 The results of the test apply only to the thickness of 5.5.8.5 This test method does not carry out dynamic mea-
the specimen as tested. No simple mathematical formula exists surements as smoke simply continues filling a closed chamber;
to calculate the specific optical density of a specimen at a therefore, the smoke obscuration values obtained do not
specimen thickness different from the thickness at which it was represent conditions of open fires.
tested. The literature contains some information on a relation-
9 6. Apparatus and Ancillary Equipment
ship between optical density and specimen thickness [1].
5.5.4 Results obtained from this test method are affected by 6.1 General—The apparatus (Fig. 1) consists of an air-tight
variations in the position of the specimen and radiometer test chamber with provision for containing a sample holder,
relative to the radiant heat source, since the relative positioning radiation cone, pilot burner, a light transmission and measuring
affects the radiant heat flux (see also Appendix X2). system and other ancillary facilities for controlling the condi-
5.5.5 The test result
...