ASTM D7236-06

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An American National Standard
Designation:D7236–06
Standard Test Method for
Flash Point by Small Scale Closed Cup Tester (Ramp
,
1 2
Method)
This standard is issued under the fixed designation D 7236; 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.
INTRODUCTION
This flash point test method is a dynamic test method and depends on a definite rate of temperature
increase to control the precision of the test method. The rate of heating may not in all cases give the
precision quoted in the test method because of the low thermal conductivity of certain materials. The
use of an equilibrium method such as Test Methods D 3828, Method B improves the prediction of
flammabilityforsuchmaterials,asthevaporsabovethetestspecimenandthetestspecimenarecloser
to thermal equilibrium.
Flash point values are a function of the apparatus design, the condition of the apparatus used, and
the operational procedure carried out. Flash point can therefore only be defined in terms of a standard
test method, and no general valid correlation can be guaranteed between results obtained by different
test methods or with test apparatus different than that specified.
1. Scope responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
1.1 This test method covers the determination of the flash
bility of regulatory limitations prior to use. For specific hazard
point of aviation turbine fuel, diesel fuel, kerosine and related
statements, see Section 7 and the Material Safety Data Sheet
products in the temperature range of 40 to 135°C by a small
for the product being tested.
scale closed cup apparatus.
1.2 This test method is only applicable to homogeneous
2. Referenced Documents
materials that are liquid at or near ambient temperature and at
2.1 ASTM Standards:
temperatures required to perform the test.
D 3828 TestMethodsforFlashPointbySmallScaleClosed
1.3 This test method is not applicable to liquids contami-
Cup Tester
nated by traces of highly volatile materials.
D 4057 Practice for Manual Sampling of Petroleum and
1.4 This test method is a dynamic method and depends on a
Petroleum Products
definite rate of temperature increase. It is one of many flash
D 4177 Practice for Automatic Sampling of Petroleum and
point methods available, and every flash point test method,
Petroleum Products
including this one, is an empirical one.
D 6299 Practice for Applying Statistical Quality Assurance
1.5 If the user’s specification requires a defined flash point
Techniques to Evaluate Analytical Measurement System
method, neither this test nor any other method should be
Performance
substituted for the prescribed method without obtaining com-
D 6300 Practice for Determination of Precision and Bias
parative data and an agreement from the specifier.
Data for Use in Test Methods for Petroleum Products and
1.6 The values stated in SI units are to be regarded as
Lubricants
standard. No other units of measurement are included in this
E 300 Practice for Sampling Industrial Chemicals
standard.
2.2 ISO Standards:
1.7 This standard does not purport to address all of the
ISO Guide 34 Quality Systems Guidelines for the Produc-
safety concerns, if any, associated with its use. It is the
tion of Reference Materials
1 3
This test method is under the jurisdiction of ASTM Committee D02 on For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
D02.08 on Volatility. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Jan. 1, 2006. Published March 2006. the ASTM website.
2 4
This test method is being jointly developed and harmonized with the Energy Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
Institute. 4th Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D7236–06
ISO Guide 35 Certification of Reference Material—General below the expected flash point. If a freezer is used, it shall be
and Statistical Principles of explosion-protected design.
6.5 Draft Shield, a shield fitted at the back and on two sides
3. Terminology
of the instrument, for use in circumstances where natural
protection from drafts does not exist.
3.1 Definitions:
3.1.1 flash point, n—lowest temperature corrected to a
NOTE 2—A shield 350-mm high, 480-mm wide, and 240-mm deep, is
pressure of 101.3 kPa, at which application of a test flame
suitable.
causes the vapors of a test specimen of the sample to ignite
7. Reagents and Materials
momentarily under the specified conditions of the test.
3.2 Definitions of Terms Specific to This Standard:
7.1 Cleaning Solvent—Use only noncorrosive solvents ca-
3.2.1 dynamic, adj—the condition where the vapor above
pableofcleaningthetestcupandlidassembly.Twocommonly
the test specimen, and the test cup, are not in temperature
used solvents are toluene and acetone. (Warning—Toluene,
equilibrium at the time the test flame is applied.
acetone and many solvents are flammable and a health hazard.
Dispose of solvents and waste material in accordance with
4. Summary of Test Method
local regulations.)
4.1 A 2 6 0.1 mL test specimen is introduced into the test
7.2 Butane or Natural Gas—For use as the pilot and test
cup that is then heated automatically at a constant rate of 2 6
flame. (Warning—Butane and natural gases are flammable
0.5°C/min. A gas test flame is directed through an opening
and a health hazard.)
shutter, in the test cup lid, at specified temperature intervals
8. Sampling
until a flash is detected by the automatic flash detector. The
flash is reported as defined in 3.1.1.
8.1 Obtain at least a 25 mL sample from a bulk test site in
accordance with Practices D 4057, D 4177, E 300 or other
5. Significance and Use
comparable sampling practices.
5.1 The flash point temperature is one measure of the
8.2 Store samples in clean, tightly sealed containers at
tendency of the test specimen to form a flammable mixture
normal room temperature (20 to 25°C) or colder. Ensure that
with air under controlled laboratory conditions. It is only one
the container is 85 to 95 % full.
of a number of properties that must be considered in assessing
8.3 Do not store samples for an extended period of time in
the overall flammability hazard of a material.
gas permeable containers, such as plastic, because volatile
5.2 Flash point is used in shipping and safety regulations to
material may diffuse through the walls of the container.
define flammable and combustible materials and classify them.
Samples in leaky containers are suspect and not a source of
Consult the particular regulation involved for precise defini-
valid results.
tions of these classifications.
8.4 Erroneously high flash points can be obtained when
5.3 This test method can be used to measure and describe
precautionsarenottakentoavoidlossofvolatilematerials.Do
the properties of materials in response to heat and a test flame
not open containers unnecessarily. Do not make a transfer
under controlled laboratory conditions and shall not be used to
unless the sample temperature is at least 10°C below the
describe or appraise the fire hazard or fire risk of materials
expected flash point.Where possible perform the flash point as
under actual fire conditions. However, results of this test
the first test on the sample.
method may be used as elements of a fire risk assessment, that
8.5 Samples containing dissolved or free water may be
takes into account all of the factors that are pertinent to an
dehydrated with calcium chloride. Warming the sample is
assessment of the fire hazard of a particular end use.
permitted, but do not heat the sample above a temperature of
10°C below its expected flash point. (Warning—If the sample
6. Apparatus
is expected of containing volatile components, the treatment as
6.1 Flash Point Apparatus—The apparatus consists of an
described in 8.5 should be omitted.)
electrically heated test cup that is controlled automatically to
8.6 Cool or adjust the temperature of the sample and its
give a temperature increase of 2.0 6 0.5°C/min, a lid and
containertoatleast10°Cbelowtheexpectedflashpointbefore
shutter assembly, a pilot and test flame, an automatic flash
opening to remove the test specimen. If an aliquot of the
detector and a temperature display that displays and holds the
original sample is to be stored prior to testing, ensure that the
test temperature when a flash is detected. The key parts and
container is filled to between 85 and 95 % of its capacity.
dimensions are described in Annex A1 and illustrated in Fig.
Gently mix the subsample to ensure uniformity while mini-
A1.1.
mizing the possible loss of volatile components and light ends.
6.2 Syringe, 2 mL, adjusted to deliver 2.00 6 0.1 mL.
NOTE 3—Results of flash point tests may be affected if the sample
6.3 Barometer, accurate to 0.5 kPa. Barometers pre-
volume falls below 85 % of the container’s capacity.
corrected to give sea level readings, such as those used at
weather stations and airports, shall not be used.
9. Preparation of Apparatus
9.1 Support the apparatus (AnnexA1) on a level and steady
NOTE 1—Automaticbarometriccorrectioninaccordancewith12.2may
be installed in the apparatus. surface in a draft-free position (see Notes 4 and 5).
6.4 Cooling Bath or Freezer, for cooling the samples, if
NOTE 4—A draft shield (6.5) is recommended to be used when natural
required, and capable of cooling the sample to at least 10°C protection from drafts does not exist.
D7236–06
NOTE 5—When testing materials that may produce toxic vapors, the
closed overa2to3-s period, at 1°C intervals for temperatures
apparatus may be located in a fume hood with an individual control of air
up to and including 100°C and thereafter every 2°C for
flow, adjusted such that the toxic vapors can be withdrawn without
temperatures over 100°C.
causing air currents around the test cup during the test.
11.5.1 Observethefirsttwodipsoftheflameforcontinuous
9.2 Clean the test cup, cover, and its accessories with an
burning in the orifice. If a continuous luminous flame burns in
appropriate solvent (7.1) to remove traces of gum or residue
the orifice when the slide is opened and the test flame is
from the previous test.
introduced, then the flash point lies considerably below the test
temperature. In such cases, discontinue the test and repeat the
NOTE 6—A stream of clean dry air may be used to remove the last
test with a fresh test specimen using a lower expected flash
traces of solvent used.
NOTE 7—The filler orifice may be cleaned with a pipe cleaner. point.
11.5.2 Applicationofthetestflamemaycauseabluehaloor
10. Verification of Apparatus
an enlarged flame prior to the actual flash point. This is not a
10.1 Verify that the temperature measuring device is in
flash and is ignored by the flash detector.
accordance with A1.7.
11.6 Record the displayed and held temperature of the
10.2 Verify the performance of the apparatus at least once
temperature sensor when the application of the test flame
peryearbydeterminingtheflashpointofaCertifiedReference
causes a flash to be automatically detected.
Material(CRM)thathasacertifiedflashpointreasonablyclose
11.7 Recordtheambientbarometricpressureusingabarom-
to the expected range of the samples to be tested. Examples of
eter (6.3) in the vicinity of the apparatus at the time of the test.
materials that may be used to create CRMs are listed in
NOTE 9—It is not considered necessary to correct the barometric
Appendix X1. The flash point shall be determined using the
pressure reading to 0°C, although some barometers are designed to make
procedures stated in Section 11.Appendix X1 indicates typical
this correction automatically.
limits in Table X1.1 for a typical CRM and shows how to
calculate limits for an unlisted CRM. 11.8 When the temperature at which the flash is observed is
10.3 Once the performance of the apparatus has been
less than 10°C or greater than 30°C from the start temperature
verified using a CRM, the flash point of Secondary Working of the test, the result is not valid. Repeat the test using a fresh
Standards (SWS) can be determined along with their control
test specimen adjusting the temperature of the first application
limits. These SWS can then be utilized for more frequent of the test flame until a valid determination is made.
performance checks. (See Appendix X1.)
10.4 When the flash point obtained is not within the limits
12. Calculation
stated in 10.2 or 10.3 check the condition and operation of the
12.1 Barometric Pressure Conversion—If the barometric
apparatus to ensure conformance to the details listed inAnnex
pressure reading is measured in a unit other than kilopascals,
A1, especially with regard to the action of the shutter, the
convert to kilopascals using one of the following equations:
position and size of the test flame, the heating rate and the
Reading in hPa 3 0.1 5 kPa (1)
temperature sensor readings. After any adjustment, repeat the
Reading in mbar 3 0.1 5 kPa (2)
test in 10.2 or 10.3 using a fresh test specimen, with special
attentiontotheproceduraldetailsprescribedinthetestmethod.
Reading in mmHg 3 0.1333 5 kPa (3)
12.2 Correction of Detected Flash Point to Standard Atmo-
11. Procedure
spheric Pressure—Calculate the flash point corrected to a
11.1 Set the test cup temperature to 15 6 5°C below the
standard atmospheric pressure of 101.3 kPa, T , using the
c
expected flash point temperature.
following equation:
11.2 Whenthetestcupisattherequiredtemperature,charge
T 5 T 1 0.25 ~101.3 – p! (4)
c D
a clean and dry syringe (6.2), adjusted to a temperature at least
10°C below the expected flash point, witha2mL test
where:
specimen. Close the sample container immediately after with-
T = the detected flash point temperature at ambient baro-
D
drawal of the test specimen, to minimize any loss of volatile metric pressure, expressed in degrees Celsius, and
components. p = the ambient barometric pressure, expressed in kilo-
pascals.
11.3 Carefully transfer the syringe to the filler orifice and
dischargethetestspecimenintothetestcupbyfullydepressing
NOTE 10—This equation is strictly correct only within the barometric
the syringe plunger. Remove the syringe.
pressure range from 98.0 to 104.7 kPa.
11.4 Ignite the pilot and test flames.Adjust the test flame to
conform to the size of the 4 mm gauge ring. Reset the fl
...