ASTM E1491-97

Standard Test Method for Minimum Autoignition Temperature of Dust Clouds

SCOPE
1.1 This test method determines the minimum temperature at which a given dust cloud will autoignite when exposed to air heated in a furnace at local atmospheric pressure.
1.2 Data obtained from this test method provide a relative measure of dust cloud autoignition temperatures.
1.3 This test method should be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test method may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-Sep-1997
• Technical Committee: E27 - Hazard Potential of Chemicals
• Drafting Committee: E27.05 - Explosibility and Ignitability of Dust Clouds

Relations

• Replaced By: ASTM E1491-97(2002) - Standard Test Method for Minimum Autoignition Temperature of Dust Clouds
• Effective Date: 10-Sep-1997

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E 1491 – 97
Standard Test Method for
1
Minimum Autoignition Temperature of Dust Clouds
This standard is issued under the fixed designation E 1491; 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 (ε) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
This test method covers the determination of the minimum temperature at which a dust cloud will
autoignite.The dust cloud is exposed to air heated to various temperatures in a furnace. Ignition of the
cloud is indicated by visual observation of the flame. The chemical nature of the dust as well as its
concentration, particle size, moisture, and surface area affects the results.
1. Scope E 659 Test Method for Autoignition Temperature of Liquid
3
Chemicals
1.1 This test method covers the minimum temperature at
E 1226 Test Method for Pressure and Rate of Pressure Rise
which a given dust cloud will autoignite when exposed to air
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for Combustible Dusts
heated in a furnace at local atmospheric pressure.
1.2 Data obtained from this test method provide a relative
3. Terminology
measure of dust cloud autoignition temperatures.
3.1 Definitions of Terms Specific to This Standard:
1.3 Thistestmethodshouldbeusedtomeasureanddescribe
3.1.1 dust concentration—the mass of dust divided by the
the properties of materials, products, or assemblies in response
internal volume of the test chamber.
to heat and flame under controlled laboratory conditions and
3.1.2 minimum autoignition temperature (MAIT)—themini-
shouldnotbeusedtodescribeorappraisethefirehazardorfire
mum temperature at which a dust cloud will self ignite under
risk of materials, products, or assemblies under actual fire
the specified conditions of test.
conditions.However,resultsofthistestmethodmaybeusedas
elements of a fire risk assessment which takes into account all
4. Summary of Test Method
of the factors which are pertinent to an assessment of the fire
4.1 The temperature of the furnace or oven is set at a
hazard of a particular end use.
predetermined value.
1.4 This standard does not purport to address all of the
4.2 Dust is blown into the heated furnace, which is at
safety concerns, if any, associated with its use. It is the
ambient pressure.
responsibility of the user of this standard to establish appro-
4.3 Ignitionisdeterminedbyvisualobservationoftheflame
priate safety and health practices and determine the applica-
exiting the furnace.
bility of regulatory limitations prior to use.
5. Significance and Use
2. Referenced Documents
5.1 This test method provides a procedure for performing
2.1 ASTM Standards:
laboratory tests to determine the minimum autoignition tem-
D 3173 Test Method for Moisture in theAnalysis Sample of
perature (MAIT) of a dust cloud.
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Coal and Coke
5.2 The test data developed from this test method can be
D 3175 Test Method for Volatile Matter in the Analysis
used to limit the temperature to which a dust cloud is exposed
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Sample of Coal and Coke
so as to prevent ignition of the cloud. Because of the short
duration of the test, the data obtained are most applicable to
1
This test method is under the jurisdiction ofASTM Committee E-27 on Hazard
industrialequipmentwheredustispresentasacloudforashort
Potential of Chemicalsand is the direct responsibility of Subcommittee E27.05on
time. Because of the small scale of the test and the possible
Explosibility and Ignitability of Dust Clouds.
Current edition approved Sept. 10, 1997. Published November 1997. Originally
published as E 1491 – 91. Last previous editiion E 1491 – 92.
2 3
Annual Book of ASTM Standards, Vol 05.05. 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.
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E 1491
variation of the MAIT value with scale, the data obtained by 9. Sampling
this test method may not be directly applicable to all industrial
9.1 It is not practical to specify a single method of sampling
conditions.
dust for test purposes because the character of the material and
5.3 The MAIT data can also be used in conjunction with
its available form affect selection of the sampling procedure.
minimum spark ignition data to evaluate the hazards of
Generally accepted sampling procedures should be used as
5
grinding and impact sparks in the presence of dust clouds (1
described in STP 447A.
4
and 2).
9.2 Tests may be run on an as-received sample. However,
5.4 The test values obtained are specific to the sample
due to the possible accumulation of fines at some location in a
tested, the method used, and the test equipment utilized. The
processing
...