ASTM D7094-23

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Designation: D7094 − 17a D7094 − 23
Standard Test Method for
Flash Point by Modified Continuously Closed Cup
(MCCCFP) Tester
This standard is issued under the fixed designation D7094; 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.
1. Scope*
1.1 This test method covers the determination of the flash point of fuels including diesel/biodiesel blends, lube oils, solvents, and
other liquids by a continuously closed cup tester utilizing a specimen size of 2 mL, cup size of 7 mL, with a heating rate of 2.5 °C
per minute.
1.1.1 Apparatus requiring a specimen size of 1 mL, cup size of 4 mL, and a heating rate of 5.5 °C per minute must be run
according to Test Method D6450.
1.2 This flash point test method is a dynamic method and depends on definite rates of temperature increase. It is one of the many
flash point test methods available and every flash point test method, including this one, is an empirical method.
NOTE 1—Flash point values are not a constant physical chemical property of materials tested. They 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 where different test apparatus is specified.
1.3 This test method utilizes a closed but unsealed cup with air injected into the test chamber.
1.4 This The precision of this test method is suitableapplicable for testing samples with a flash point from 35 °C to 225 °C.22.5 °C
to 235.5 °C. Determinations below and above this range may be performed; however, the precision has not been established.
NOTE 2—Flash point determinations below 35 °C and above 225 °C may be performed; however, the precision has not been determined below and above
these temperatures.
1.5 If the user’s specification requires a defined flash point method other than this method, neither this method nor any other test
method should be substituted for the prescribed test method without obtaining comparative data and an agreement from the
specifier.
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
Temperatures are in degrees Celsius, pressure in kilo-Pascals.
1.7 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific warning statements, see 7.2, 8.5, and and 10.1.28.5.
This test method is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.08 on Volatility.
Current edition approved Dec. 1, 2017Dec. 1, 2023. Published February 2018January 2024. Originally approved in 2004. Last previous edition approved in 2017 as
D7094 – 17.D7094 – 17a. DOI: 10.1520/D7094-17A.10.1520/D7094-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7094 − 23
1.8 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D4057 Practice for Manual Sampling of Petroleum and Petroleum Products
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4177 Practice for Automatic Sampling of Petroleum and Petroleum Products
D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measure-
ment System Performance
D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and
Lubricants
D6450 Test Method for Flash Point by Continuously Closed Cup (CCCFP) Tester
D6708 Practice for Statistical Assessment and Improvement of Expected Agreement Between Two Test Methods that Purport
to Measure the Same Property of a Material
E300 Practice for Sampling Industrial Chemicals
2.2 ISO Standards:
ISO Guide 3417034 Quality Systems Guidelines General requirements for the Production of Reference Materialscompetence of
reference material producers
ISO Guide 35 Certification of Reference Materials—General and Statistical PrinciplesReference materials—Guidance for
characterization and assessment of homogeneity and stability
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology D4175.
3.2 Definitions:Definitions of Terms Specific to This Standard:
3.2.1 dynamic, adj—the condition where the vapor above the test specimen and the test specimen are not in temperature
equilibrium at the time at which the ignition source is applied.
3.2.2 flash point, n—in flash point test methods, the lowest temperature of the test specimen, adjusted to account for variations in
atmospheric pressure from 101.3 kPa, at which application of an ignition source causes the vapors of the test specimen to ignite
under specified conditions of test.
3.2.2.1 Discussion—
For the purpose of this test method, the test specimen is deemed to have flashed when the hot flame of the ignited vapor causes
an instantaneous pressure increase of at least 20 kPa inside the closed measuring chamber.
4. Summary of Test Method
4.1 The lid of the test chamber is regulated to a temperature at least 18 °C below the expected flash point. A 2 mL 6 0.2 mL test
specimen of a sample is introduced into the sample cup. Both specimen and cup are at a temperature at least 18 °C below the
expected flash point; cooled if necessary. The cup is then raised and pressed onto the lid of specified dimensions to form the
continuously closed but unsealed test chamber with an overall volume of 7.0 mL 6 0.3 mL.
4.2 After closing the test chamber, the temperatures of the test specimen and the regulated lid are allowed to equilibrate to within
1 °C. Then the lid is heated at a prescribed, constant rate. For the flash tests, a high voltage arc of defined energy is discharged
inside the test chamber at regular intervals. After each ignition, a variable amount of air (see Table 1) is introduced into the test
chamber to provide the necessary oxygen for the next flash test. The pressure inside the continuously closed but unsealed test
chamber remains at ambient barometric pressure except for the short time during the air introduction and at a flash point.
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TABLE 1 Volume of Introduced Air as a Function of
Sample Temperature
Sample Temperature Introduced Volume
Range (°C) of Air (mL)
below 80 0
80 to below 150 0.5 ± 0.15
150 to below 200 1 ± 0.2
200 to below 300 1.5 ± 0.3
300 and above 2 ± 0.4
4.3 After each arc application, the instantaneous pressure increase above the ambient barometric pressure inside the test chamber
is monitored. When the pressure increase exceeds 20 kPa, the temperature at that point is recorded as the uncorrected flash point,
which is then corrected to barometric pressure.
5. Significance and Use
5.1 The flash point temperature is one measure of the tendency of the test specimen to form a flammable mixture with air under
controlled laboratory conditions. It is only one of a number of properties which must be considered in assessing the overall
flammability hazard of a material.
5.2 Flash point is used in shipping and safety regulations to define flammable and combustible materials and for classification
purposes. This definition may vary from regulation to regulation. Consult the particular regulation involved for precise definitions
of these classifications.
5.3 This test method can be used to measure and describe the properties of materials in response to heat and an ignition source
under controlled laboratory conditions and shall not be used to describe or appraise the fire hazard or fire risk of materials 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.
5.4 Flash point can also indicate the possible presence of highly volatile and flammable materials in a relatively nonvolatile or
nonflammable material, such as the contamination of lubricating oils by small amounts of diesel fuel or gasoline. This test method
was designed to be more sensitive to potential contamination than Test Method D6450.
6. Apparatus
6.1 Flash Point Apparatus, Continuously Closed Cup Operation—The type of apparatus suitable for use in this test method
employs a lid of solid brass, the temperature of which is controlled electrically. Two temperature sensors for the specimen and the
lid temperatures, respectively, two arc pins for a high voltage arc, and a connecting tube for the pressure monitoring and the air
introduction are incorporated in the lid. Associated equipment for electrically controlling the chamber temperature is used, and a
digital readout of the specimen temperature is provided. The apparatus and its critical elements are shown in Figs. A1.1 and A1.2.
6.1.1 Test Chamber—The test chamber is formed by the sample cup and the temperature-controlled lid, and shall have an overall
volume of 7 mL 6 0.3 mL. A metal-to-metal contact between the lid and the sample cup shall provide good heat contact but allow
ambient barometric pressure to be maintained inside the test chamber during the test. Critical dimensions are shown in Fig. A1.2.
The pressure inside the measuring chamber during the temperature increase is monitored. A seal that is too tight results in a
pressure increase above ambient due to the temperature and the vapor pressure of the sample. A poor heat contact results in a bigger
temperature difference between the sample and the heated lid.
6.1.2 Sample Cup—The sample cup shall be made of nickel-plated aluminum or other material with similar heat conductivity. It
shall have an overall volume of 7 mL 6 0.3 mL and shall be capable of containing 2 mL 6 0.2 mL of sample. The critical
dimensions and requirements are shown in Fig. A1.2.
6.1.3 Specimen Temperature Sensor—The specimen temperature sensor (Fig. A1.1) shall be a thermocouple (NiCr-Ni or similar)
in stainless steel of 1 mm diameter with a response time of t(90) = 3 s. It shall be immersed to a depth of at least 2 mm into the
specimen. It shall have a resolution of 0.1 °C and a minimum accuracy of 60.2 °C, preferably with a digital readout.
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6.1.4 Magnetic Stirring—The apparatus shall have provisions for stirring of the sample. A rotating magnet outside the sample cup
shall drive a small stirring magnet which is inserted into the sample cup after sample introduction. The stirring magnet shall have
a diameter of 3 mm 6 0.2 mm and a length of 12 mm 6 1 mm. The rotation speed of the driving magnet shall be between
250 r ⁄min and 270 r ⁄min.
6.1.5 Air Introduction—The apparatus shall have provisions for introduction of air immediately after each flash test. The air shall
be introduced by a short air pulse from a small membrane compressor by means of a T-inlet in the connecting tube to the pressure
transducer. The volume of the introduced air, from 0.5 mL to 2 mL, is dependent on the sample temperature (see Table 1).
6.1.6 Electrical heating and thermoelectric cooling of the lid (see the Peltier element shown in Fig. A1.1) shall be used to regulate
the temperature of the test chamber for the duration of the test. The temperature regulation shall have a minimum accuracy of
60.2 °C.
6.1.7 A high voltage electric arc shall be used for the ignition of the flammable vapor. The energy of the arc shall be 1.3 J 6 0.3 J
(1.3 Ws 6 0.3 Ws) per arc and the energy shall be applied within 19 m ⁄s 6 2 m ⁄s. ((BecauseWarning—Because samples
containing low flash material or having a flash point below the preset initial temperature can oversaturate the vapor inside the
chamber and hence prohibit the detection of a flash point in the chosen range, a precautionary arc set at 5 °C intervals is required
while the lid and sample cup temperatures are equalizing.) samples containing low flash material or having a flash point below the
preset initial temperature can oversaturate the vapor inside the chamber and hence prohibit the detection of a flash point in the
chosen range, a precautionary arc set at 5 °C intervals is required while the lid and sample cup temperatures are equalizing.)
6.1.8 The pressure transducer for the flash point detection shall be connected to the connecting tube in the lid and shall have a
minimum operational range from 80 kPa to 177 kPa with a minimum resolution of 0.1 kPa and a minimum accuracy of 60.5 kPa.
It shall be capable of detecting an instantaneous pressure increase above barometric pressure of a minimum of 20 kPa within
100 m ⁄s.
NOTE 2—The monitoring of the instantaneous pressure increase above barometric pressure is one of several methods to determine a flash inside the test
chamber. A pressure increase of 20 kPa corresponds to a flame volume of approximately 2.5 mL.
NOTE 3—An automatic barometric correction, which is performed according to the procedure described in 12.1, can be installed in the tester. The absolute
pressure reading of the pressure transducer described in 6.1.8 may be used for the correction.
6.1.9 The introduction of a test specimen of 2.0 mL 6 0.2 mL shall be accomplished by the use of a pipette or syringe of the
required accuracy.
7. Reagents and Materials
7.1 Purity of Reagents—Use only chemicals of purity specified in Table X1.1. Unless otherwise indicated, it is intended that all
reagents conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where such
specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficient purity to
permit its use without lessening the accuracy of the determination.
7.1.1 Anisole—(Warning—See 7.2.)
7.1.2 Dodecane—(Warning—See 7.2.)
7.2 Cleaning Solvents—Use only noncorrosive solvents capable of cleaning the sample cup and the lid. Two commonly used
solvents are toluene and acetone. (Warning—Anisole, dodecane, toluene, acetone, and many solvents are flammable and are health
hazards. Dispose of solvents and waste material in accordance with local regulations.)
Reagent Chemicals, American Chemical Society Specifications,ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference
Materials, American Chemical Society, Washington, DC. For Suggestionssuggestions on the testing of reagents not listed by the American Chemical Society, see
AnnualAnalar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial
Convention, Inc. (USPC), Rockville, MD.
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8. Sampling
8.1 Obtain at least a 50 mL sample from a bulk test site in accordance with the instructions given in Practice D4057, D4177, or
E300. Store the sample in a clean, tightly sealed container at a low temperature.
8.2 Do not store samples for an extended period of time in gas-permeable containers such as plastic, because volatile material may
diffuse through the walls of the container. Discard samples in leaky containers and obtain new samples.
8.3 Erroneously high flash points can be obtained when precautions are not taken to avoid loss of volatile material. Do not open
containers unnecessarily. Do not make a transfer unless the sample temperature is at least 18 °C below the expected flash point.
When possible, perform the flash point as the first test.
8.4 Samples of very viscous materials may be warmed until they are reasonably fluid before they are tested. However, do not heat
the unsealed sample above a temperature of 18 °C below its expected flash point.
8.5 Samples containing dissolved or free water may be dehydrated with calcium chloride or by filtering through a qualitative filter
paper or a loose plug of dry absorbent cotton. Warming the sample is permitted, but it should not be heated above a temperature
of 18 °C below its expected flash point. ((BecauseWarning—Because samples containing volatile material will lose volatiles and
then yield incorrectly high flash points, the treatment described in 8.4 and 8.5 is not suitable for such samples.) samples containing
volatile material will lose volatiles and then yield incorrectly high flash points, the treatment described in 8.4 and 8.5 is not suitable
for such samples.)
9. Quality Control Checks
9.1 Verify the performance of the instrument at least once per year by determining the flash point of a certified reference material
(CRM) such as those listed in Appendix X1, which is reasonably close to the expected temperature range of the samples to be
tested. The material shall be tested in accordance with Section 11 of this test method, and the observed flash point obtained in 11.11
shall be corrected for barometric pressure as described in Section 12. The flash point shall be within the limits stated in Table X1.1.
Follow the manufacturer’s instructions regarding acceptable tolerances for CRMs and SWSs, if tighter tolerances are
recommended by the manufacturer.
9.2 Once the performance of the instrument has been verified, the flash point of Secondary Working Standards (SWSs) can be
determined along with their control limits. These secondary materials can then be utilized for more frequent performance checks
(see Appendix X1). A performance check with a SWS shall be performed every day the instrument is in use.
9.3 When the flash point obtained is not within the limits stated in 9.1 or 9.2, follow the manufacturer’s instruction for cleaning
and maintenance, and check the instrument calibration (see Section 10). After any adjustment, repeat the test in 9.1 or 9.2, using
a fresh test specimen, with special attention to the procedural details prescribed in this test method. (Warning—The use of single
component verification materials, such as those listed in Table X1.1, will only prove the calibration of the equipment. It will not
check the accuracy of the entire test method which includes sample handling. Losses due to evaporation of a single component
material will not affect the flash point as is th
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