ASTM E502-84(1994)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: E 502 – 84 (Reapproved 1994)
Standard Test Method for
Selection and Use of ASTM Standards for the Determination
of Flash Point of Chemicals by Closed Cup Methods
This standard is issued under the fixed designation E 502; 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 D 3278 Test Method for Flash Point of Liquids by Setaflash
Closed Tester
1.1 This test method covers the determination of the flash
D 3827 Test Method for Estimation of Solubility of Gases
point of liquid and solid chemical compounds flashing from
in Petroleum and Other Organic Liquid
below − 10 to 370°C (16 to 700°F). The procedures and
D 3828 Test Method for Flash Point by Setaflash Closed
apparatus in Test Methods D 56, D 93, D 3278, D 3828, and
Tester
D 3941 are to be used. Modification to these procedures are
D 3934 Test Method for Flash/No Flash Test Equilibrium
specified for tests on solids and viscous liquids. The signifi-
Method by a Closed-Cup Apparatus
cance of the results obtained is discussed along with possible
D 3941 Test Method for Flash Point by the Equilibrium
sources of error and factors that might cause interference.
Method with a Closed-Cup Apparatus
1.2 Suggestions for adapting this procedure to mixtures of
E 681 Test Method for Limits of Flammability of Chemi-
chemicals are included (see Appendix X2).
cals
1.3 This test method should be used to measure and describe
the properties of materials, products, or assemblies in response
3. Terminology
to heat and flame under controlled laboratory conditions and
3.1 Definition:
should not be used to describe or appraise the fire hazard or fire
3.1.1 flash point—the lowest temperature, corrected to a
risk of materials or assemblies under actual fire conditions.
pressure of 760 mm Hg (101.3 kPa) (1013 mbar) at which
However, results of this test method may be used as elements
application of an ignition source causes the vapors of a
of a fire risk assessment that take into account all of the factors
specimen to ignite under specified conditions of test.
that are pertinent to an assessment of the fire hazard of a
particular end use.
4. Summary of Test Method
1.4 This standard does not purport to address all of the
4.1 The specimen is placed in a closed cup and in the
safety concerns, if any, associated with its use. It is the
Setaflash method equilibrated at a test temperature, in the
responsibility of the user of this standard to establish appro-
Pensky-Martens Method heated at a controlled rate with
priate safety and health practices and determine the applica-
stirring, and in the Tag Method also heated at a controlled rate
bility of regulatory limitations prior to use. See also Section 8.
but without stirring. A small flame is directed into the vapor
2. Referenced Documents space of each cup at specified intervals, with simultaneous
interruption of stirring in the Pensky-Martens Method, to
2.1 ASTM Standards:
2 determine whether a flash occurs or not. In Test Method
D 56 Test Method for Flash Point by Tag Closed Tester
D 3941, the specimen is heated at a slower rate than in the
D 92 Test Method for Flash and Fire Points by Cleveland
2 other controlled heating methods, maintaining a small tempera-
Open Cup
ture differential between bath and specimen.
D 93 Test Methods for Flash Point by Pensky-Martens
Closed Tester
5. Significance and Use
D 270 Method of Sampling Petroleum and Petroleum Prod-
3 5.1 The flash point measures the response of the sample to
ucts
heat and flame under controlled laboratory conditions. It is
D 1310 Test Method for Flash Point and Fire Points of
2 only one of a number of properties that must be considered in
Liquids by Tag Open-Cup Apparatus
assessing the overall flammability hazard of a material.
5.2 As a result of physical factors inherent in the apparatus
and procedure, the closed cup flash point does not necessarily
This test method is under jurisdiction of ASTM Committee E-27 on Hazard
Potential of Chemicals and is the direct responsibility of Subcommittee E27.04 on
Flammability and Ignitability of Chemicals.
Current edition approved July 27, 1984. Published September 1984. Annual Book of ASTM Standards, Vol 06.03.
2 5
Annual Book of ASTM Standards, Vol 05.01. Annual Book of ASTM Standards, Vol 05.03.
3 6
Discontinued, See 1983 Annual Book of ASTM Standards, Vol 05.01. Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
E 502
represent the minimum temperature at which a material can require complete protective coverage such as an air-supplied
evolve flammable vapors, and the absence of a flash point does plastic suit. (Two examples of the latter type of material are
not guarantee nonflammability (see Appendix X1 and Appen- dimethyl sulfate and pure mercaptans.) Tests on these highly
dix X2). toxic or obnoxious materials may also be conducted in com-
5.3 Flash point is used in shipping and safety regulations to pletely isolated, closed systems, such as glove boxes. In this
define flammable and combustible materials. Test Methods case, procedures should ensure an uncontaminated air system
D 56, D 93, and D 3278 are specified as test methods for in the box, and should prevent a buildup of vapors from the
determining the flash point of these materials. material under test.
5.4 Setaflash methods involving equilibrium procedures and 8.2 Dry Ice Use:
only one flame pass per specimen are preferred. 8.2.1 Exercise care in the use of dry ice for sample and
apparatus cooling. Avoid contact with dry ice to prevent
6. Interferences
frostbite. Glass bottles or vials of chemicals should not be
6.1 Incorrect flash points can be obtained when testing placed directly in dry ice or dry ice baths because of the
chemicals corrosive to the materials of construction of the cup. possibility of breakage due to thermal shock.
(For example, certain amines and acid chlorides react with the 8.3 Tests of Explosives and Propellants:
standard aluminum Setaflash cup causing erroneously low flash 8.3.1 Flash tests should not be conducted on potential or
points, perhaps due to hydrogen formation.) Cups employing known explosive or propellant materials without complete
alternative materials of construction, electroplating or plastic prior knowledge that burning will not result in propagation to
coating can provide corrosion resistance. Results in non- an explosive decomposition. Properly barricaded or remotely
operated automatic testers should be used if precise flash points
standard cups, particularly in non-equilibrium tests, may differ
slightly from those obtained in this test method. are needed.
8.4 Pyrophoric Materials:
7. Apparatus
8.4.1 Flash point apparatus is not applicable for the evalu-
ation of pyrophoric materials and should not be used for this
7.1 Tag Closed-Cup Tester, including thermometers, shall
purpose.
be as shown in Test Methods D 56 and D 3941.
7.2 Penksy-Martens Closed-Cup Tester, including ther-
9. Preparation of Sample
mometers, shall be as shown in Test Methods D 93.
9.1 Obtain samples representative of the batch under test.
7.3 Setaflash Closed Tester, including thermometers, shall
Test Method D 270 can be used as a reference on sampling
be as shown in Test Methods D 3278 or D 3828.
techniques. With mixtures and with samples containing impu-
NOTE 1—Some automatic flash point testers may save testing time and
rities, take care to avoid the loss of volatile components during
permit the use of small samples. If automatic testers are used, the user
sampling and handling for testing. When heating viscous or
must be certain that all instructions for calibration and operation are
solid materials for ease of pouring, samples must be held at
followed to ensure that the results are equivalent to those obtained on the
temperatures below, or as close as possible to, those specified
ASTM standard equipment. For regulation purposes or in cases of dispute,
in the various test methods. Discard samples from leaking or
the flash point as determined on the manual tester shall be the accepted
contaminated containers. Samples that are hygroscopic should
value.
NOTE 2—ASTM thermometers 33C or 33F may be used in the Tag
not be exposed to moisture or moist air.
Tester instead of those specified in Test Method D 56 when conducting
9.2 Samples should not be stored in plastic (polyethylene,
tests at temperatures below − 10°C (14°F). Slight stem corrections may be
polypropylene, etc.) bottles, since volatile materials may dif-
necessary and care should be taken to avoid freezing the mercury in the
fuse through the walls of the bottle.
thermometer by cooling below − 40°C (−40°F).
7.4 Shield, as described in Test Method D 3941 or Test Method D 1310.
10. Preparation of Apparatus
10.1 Support the appropriate flash-point tester on a level,
8. Hazards
steady work surface in a draft-free location. If a draft-free
8.1 Toxicity of Chemical and Combustion Products:
location is not available, use a shield surrounding the tester on
8.1.1 Isolate or control operations on toxic or corrosive
three sides. The shield should be approximately 460 mm (18
materials to prevent exposure to any personnel.
in.) wide and 610 mm (24 in.) high.
8.1.2 Since flash point tests are conducted in still air, the use
NOTE 3—An area capable of being partially darkened is advantageous
of forced circulation for removal of toxic or nuisance fumes or
since it aids in the detection of the relatively nonluminous flames
combustion products is restricted. However, a laboratory fume
sometimes encountered in flash-point testing.
hood equipped with an exhaust damper that can be completely
NOTE 4—Test Method D 1310 gives a design for a draft shield suitable
closed provides an ideal location for maintaining draft-free
for standard flash-point testers.
conditions and provides the ability to readily exhaust danger-
ous vapors and combustion products when necessary.
11. Calibration
8.1.3 Use respiratory and splash protective devices as ap-
11.1 Check the condition and operation of the Tag, Pensky-
propriate with toxic or corrosive materials. In most cases,
Martens and Setaflash testers as specified in Test Methods
approved cartridge respirators are adequate respiratory protec-
D 56, D 93, D 3278, or D 3828, respectively.
tion for the concentrations normally encountered in flash-point
12. Procedure
testing. Certain toxic or unusual materials, however, may
require an air-supplied respirator and extreme cases may 12.1 Follow the procedures outlined in Test Methods D 56
E 502
specified heating rates are maintained in the temperature range in the
or D 3941 (Tag Closed Cup), D 3278 or D 3827 (Setaflash
vicinity of the flash point. This is permissible provided that, during the fast
Closed Cup), and D 93 (Pensky Martens Closed Cup), as is
heat-up period, the highest temperature of the material (next to the cup
necessary. Certain explanatory notes and procedure modifica-
wall) never exceeds a temperature 11°C (20°F) below the flash point for
tions not contained in the individual methods are given below.
the Pensky-Martens method. Use extreme care when using fast heat-up in
Occasionally, particularly near the temperature of the actual
the Pensky-Martens method since there are no provisions for bath
flash point, the application of the test flame will cause a halo or
temperature measurement.12.5 For liquids with a viscosity equal to or
−3 2
test flame enlargement that should be ignored. In some cases greater than 15 3 10 m /s (150 cSt at 25°C) (77°F) and solid materials
that flash while solid (Note 11), the following procedures apply:
this test flame enlargement will not lead to a flash point on an
increase in temperature.
12.4.2 Use the Setaflash Test Methods D 3278 or Test
−6 2
12.2 For liquids with a viscosity less than 5.8 3 10 m /s
Method D 3828 with the following modification:
−6 2
(5.8 cSt) at 38°C (100°F), or 9.5 3 10 m /s (9.5 cSt) at 25°C
12.4.2.1 Determine the flash point in the Setaflash unit using
(77°F), observe the following:
a holding time of 6 min at the test temperature instead of 1 or
12.2.1 If the flash point is below 93°C (200°F), use the
2 min normally employed.
Setaflash (Test Method D 3278 or D 3828) or Tag (Test Method
12.4.2.2 Methods for loading the sample cup with highly
D 56) apparatus and procedures.
viscous liquids or solids are given in Test Methods D 3278.
12.2.2 If the flash point is 93°C (200°F) or above, use the
Solid materials can be loaded with a spoon.
Setaflash (Test Method D 3828) or Pensky-Martens (Test
12.5 For equilibrium flash point method using the Tag
Methods D 93) apparatus and procedures.
Closed Cup Tester, the following applies:
12.5.1 For liquids with a viscosity equal to or greater than
NOTE 5—The electric heaters on some Tag Testers may be of insuffi-
−6
2 −6 2
5.8 3 10 m /s (5.8 cSt at 38°C (100°F) or 9.5 3 10 m /s
cient capacity to maintain the specified heating rates when operating in the
upper ranges of this practice. Heat input can be increased slightly by using (9.5 cSt) at 25°C (77°F) and a flash point below 93°C (200°F),
a variable transformer to increase the voltage slightly on the heaters.
Test Method D 3941 may be used using the Tag Closed Cup.
Insulation can be applied to the exterior of the bath to reduce heat losses.
12.5.2 Test Method D 3941 may also be used for the high
NOTE 6—With low temperature operation in the Setaflash methods,
viscosity liquids and solids covered in 12.5 (Note 11). Observe
equilibrium may be difficult to maintain due to heating by natural
the temperature differences between bath and sample specified
convection. It, therefore, will be necessary to cool the cup and sample
in Test Method D 3941. (The Tag tester is very inefficient for
below the anticipated flash point before specimen introduction (see Test
testing these materials since large sample quantities and very
Methods D 3278).
long testing times are required.)
NOTE 7—In the Tag Method (Test Method D 56), natural warming rates
sometimes exceed 1°C (2°F)/min. These rates can be reduced by insulat-
NOTE 10—With highly viscous materials it may be advantageous to fill
ing the outside of the bath container. A laboratory refrigerated circulator
the tag closed cup vessel directly to a 50-mL line on the sample cup rather
may be used. One advantage of this system is that circulation of the
than to use the graduated cylinder specified in Test Method D 56.
refrigerant bath with the system gradually warming up can serve as a
Significant quantities of
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