ASTM E1515-14

Standard Test Method for Minimum Explosible Concentration of Combustible Dusts

SIGNIFICANCE AND USE
5.1 This test method provides a procedure for performing laboratory tests to evaluate relative deflagration parameters of dusts.  
5.2 The MEC as measured by this test method provides a relative measure of the concentration of a dust cloud necessary for an explosion.  
5.3 Since the MEC as measured by this test method may vary with the uniformity of the dust dispersion, energy of the ignitor, and propagation criteria, the MEC should be considered a relative rather than absolute measurement.  
5.4 If too weak an ignition source is used, the measured MEC would be higher than the “true” value. This is an ignitability limit rather than a flammability limit, and the test could be described as “underdriven.” Ideally, the ignition energy is increased until the measured MEC is independent of ignition energy. However, at some point the ignition energy may become too strong for the size of the test chamber, and the system becomes “overdriven.” When the ignitor flame becomes too large relative to the chamber volume, a test could appear to result in an explosion, while it is actually just dust burning in the ignitor flame with no real propagation beyond the ignitor.  
5.5 The recommended ignition source for measuring the MEC of dusts in 20-L chambers is a 2500 or 5000 J pyrotechnic ignitor.4 Measuring the MEC at both ignition energies will provide information on the possible overdriving of the system.5 To evaluate the effect of possible overdriving in a 20-L chamber, comparison tests may also be made in a larger chamber, such as a 1 m3-chamber.  
5.6 If a dust ignites with a 5000 J ignitor but not with a 2500 J ignitor in a 20-L chamber, this may be an overdriven system.5 In this case, it is recommended that the dust be tested with a 10 000 J ignitor in a larger chamber, such as a 1 m3-chamber, to determine if it is actually explosible.  
5.7 The values obtained by this test method are specific to the sample tested (particularly the particle size distribution) and the met...
SCOPE
1.1 This test method covers the determination of the minimum concentration of a dust-air mixture that will propagate a deflagration in a near-spherical closed vessel of 20 L or greater volume.
Note 1: The minimum explosible concentration (MEC) is also referred to as the lower explosibility limit (LEL) or lean flammability limit (LFL).  
1.2 Data obtained from this test method provide a relative measure of the deflagration characteristics of dust clouds.  
1.3 This test method should be used to measure and describe the properties of materials 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 may be used as elements of a fire risk assessment that takes into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 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.  Specific precautionary statements are given in Section 8.

General Information

• Status: Historical
• Publication Date: 30-Nov-2014
• ICS: 13.230 - Explosion protection
• Technical Committee: E27 - Hazard Potential of Chemicals
• Drafting Committee: E27.05 - Explosibility and Ignitability of Dust Clouds

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:E1515 −14
Standard Test Method for
1
Minimum Explosible Concentration of Combustible Dusts
This standard is issued under the fixed designation E1515; 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.
INTRODUCTION
This test method describes procedures for measuring the minimum concentration of a combustible
dust (dispersed in air) that is capable of propagating a deflagration. The tests are made in laboratory
chambers that have volumes of 20 L or larger.
1. Scope 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the determination of the mini-
D3173 Test Method for Moisture in the Analysis Sample of
mum concentration of a dust-air mixture that will propagate a
Coal and Coke
deflagration in a near-spherical closed vessel of 20 Lor greater
D3175 Test Method for Volatile Matter in the Analysis
volume.
Sample of Coal and Coke
NOTE 1—The minimum explosible concentration (MEC) is also re-
E681 Test Method for Concentration Limits of Flammability
ferred to as the lower explosibility limit (LEL) or lean flammability limit
of Chemicals (Vapors and Gases)
(LFL).
E1226 Test Method for Explosibility of Dust Clouds
1.2 Data obtained from this test method provide a relative 3
2.2 CEN/CENELEC Publications:
measure of the deflagration characteristics of dust clouds.
EN 14034–3 Determination of Explosion Characteristics of
Dust Clouds – Part 3: Determination of the Lower
1.3 Thistestmethodshouldbeusedtomeasureanddescribe
Explosion Limit LEL of Dust Clouds
the properties of materials in response to heat and flame under
controlled laboratory conditions and should not be used to
3. Terminology
describe or appraise the fire hazard or fire risk of materials,
products, or assemblies under actual fire conditions. However,
3.1 Definitions of Terms Specific to This Standard:
results of this test may be used as elements of a fire risk
3.1.1 dust concentration, n—the mass of dust divided by the
assessment that takes into account all of the factors that are internal volume of the test chamber.
pertinent to an assessment of the fire hazard of a particular end
3.1.2 (dP/dt) ,n—themaximumrateofpressureriseduring
ex
use.
the course of a single deflagration test.
1.4 The values stated in SI units are to be regarded as 3.1.3 minimum explosible concentration (MEC), n—the
standard. No other units of measurement are included in this minimum concentration of a combustible dust cloud that is
standard. capable of propagating a deflagration through a well dispersed
mixture of the dust and air under the specified conditions of
1.5 This standard does not purport to address all of the
test.
safety concerns, if any, associated with its use. It is the
3.1.4 P ,n—the absolute pressure at the time the
ignition
responsibility of the user of this standard to establish appro-
ignitor is activated, see Fig. 1.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. Specific precau- 3.1.5 ∆P ,n—thepressureriseinthechamberduetothe
ignitor
tionary statements are given in Section 8.
ignitor by itself in air at atmospheric pressure
1 2
This test method is under the jurisdiction ofASTM Committee E27 on Hazard For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Potential of Chemicals and is the direct responsibility of Subcommittee E27.05 on contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Explosibility and Ignitability of Dust Clouds. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2014. Published January 2015. Originally the ASTM website.
3
approved in 1993. Last previous edition approved in 2007 as E1515 – 07. DOI: Available from European Committee for Standardization (CEN), Avenue
10.1520/E1515-14. Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1515−14
FIG. 1Typical Recorder Tracings for a Weak Dust Deflagration in a 20-L Chamber, using a 2500 J Ignitor
3.1.6 P ,n—the maximum explosion pressure (absolute) 4.2 Ignition of this dust-air mixture is then attempted after a
ex,a
reachedduringthecourseofasingledeflagrationtest(seeFigs. specified delay time by an ignition source located near the
1 and 2). center of the chamber.
3.1.7 P ,n—maximum pressure rise produced during the
m
4.3 The pressure time curve is recorded on a suitable piece
course of a single deflagration test that is corrected for the
of
...

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: E1515 − 07 E1515 − 14
Standard Test Method for
1
Minimum Explosible Concentration of Combustible Dusts
This standard is issued under the fixed designation E1515; 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.
INTRODUCTION
This test method describes procedures for measuring the minimum concentration of a combustible
dust (dispersed in air) that is capable of propagating a deflagration. The tests are made in laboratory
chambers that have volumes of 20 L or larger.
1. Scope
1.1 This test method covers the determination of the minimum concentration of a dust-air mixture that will propagate a
deflagration in a near-spherical closed vessel of 20 L or greater volume.
NOTE 1—The minimum explosible concentration (MEC) is also referred to as the lower explosibility limit (LEL) or lean flammability limit (LFL).
1.2 Data obtained from this test method provide a relative measure of the deflagration characteristics of dust clouds.
1.3 This test method should be used to measure and describe the properties of materials 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 may be used as elements of a fire risk assessment that takes
into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use.
1.4 The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.
1.5 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. Specific precautionary statements are given in Section 8.
2. Referenced Documents
2
2.1 ASTM Standards:
D3173 Test Method for Moisture in the Analysis Sample of Coal and Coke
D3175 Test Method for Volatile Matter in the Analysis Sample of Coal and Coke
E681 Test Method for Concentration Limits of Flammability of Chemicals (Vapors and Gases)
E1226 Test Method for Explosibility of Dust Clouds
3
2.2 CEN/CENELEC Publications:
EN 14034–3 Determination of Explosion Characteristics of Dust Clouds – Part 3: Determination of the Lower Explosion Limit
LEL of Dust Clouds
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 dust concentration, n—the mass of dust divided by the internal volume of the test chamber.
3.1.2 (dP/dt) , n—the maximum rate of pressure rise during the course of a single deflagration test.
ex
1
This test method is under the jurisdiction of ASTM Committee E27 on Hazard Potential of Chemicals and is the direct responsibility of Subcommittee E27.05 on
Explosibility and Ignitability of Dust Clouds.
Current edition approved Oct. 1, 2007Dec. 1, 2014. Published November 2007January 2015. Originally approved in 1993. Last previous edition approved in 20032007
as E1515 – 03a.E1515 – 07. DOI: 10.1520/E1515-07.10.1520/E1515-14.
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.
3
Available from European Committee for Standardization (CEN), Avenue Marnix 17, B-1000, Brussels, Belgium, http://www.cen.eu.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E1515 − 14
3.1.3 minimum explosible concentration (MEC), n—the minimum concentration of a combustible dust cloud that is capable of
propagating a deflagration through a well dispersed mixture of the dust and air under the specified conditions of test.
3.1.4 P , n—the absolute pressure at the time the ignitor is activated, see Fig. 1.
ignition
3.1.5 ΔP , n—the pressure rise in the chamber due to the ignitor by itself in air at atmospheric pressure
ignitor
3.1.6 P , n—the maximum explosion pressure (absolute) reached during the course of a single deflagration test (see Figs. 1
ex,a
and 2).
3.1.7 P , n—maximum pressure rise produced
...