1、Designation: E 502 07Standard Test Method forSelection and Use of ASTM Standards for the Determinationof Flash Point of Chemicals by Closed Cup Methods1This standard is issued under the fixed designation E 502; the number immediately following the designation indicates the year oforiginal adoption o
2、r, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the flashpoint of liquid and sol
3、id chemical compounds flashing frombelow 10 to 370C (16 to 700F). The procedures andapparatus in Test Methods D 56, D 93, D 3278, D 3828, andD 3941 are to be used. Modification to these procedures arespecified for tests on solids and viscous liquids. The signifi-cance of the results obtained is disc
4、ussed along with possiblesources of error and factors that might cause interference.1.2 Suggestions for adapting this procedure to mixtures ofchemicals are included (see Appendix X2).1.3 This test method should be used to measure and describethe properties of materials, products, or assemblies in re
5、sponseto heat and flame under controlled laboratory conditions andshould not be used to describe or appraise the fire hazard or firerisk of materials or assemblies under actual fire conditions.However, results of this test method may be used as elementsof a fire risk assessment that take into accoun
6、t all of the factorsthat are pertinent to an assessment of the fire hazard of aparticular end use.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health
7、 practices and determine the applica-bility of regulatory limitations prior to use. See also Section 8.2. Referenced Documents2.1 ASTM Standards:2D56 Test Method for Flash Point by Tag Closed Cup TesterD92 Test Method for Flash and Fire Points by ClevelandOpen Cup TesterD93 Test Methods for Flash Po
8、int by Pensky-MartensClosed Cup TesterD 270 Method of Sampling Petroleum and Petroleum Prod-ucts3D 1310 Test Method for Flash Point and Fire Point ofLiquids by Tag Open-Cup ApparatusD 3278 Test Methods for Flash Point of Liquids by SmallScale Closed-Cup ApparatusD 3827 Test Method for Estimation of
9、Solubility of Gasesin Petroleum and Other Organic LiquidsD 3828 Test Methods for Flash Point by Small Scale ClosedCup TesterD 3934 Test Method for Flash/No Flash TestEquilibriumMethod by a Closed-Cup ApparatusD 3941 Test Method for Flash Point by the EquilibriumMethod With a Closed-Cup ApparatusE 68
10、1 Test Method for Concentration Limits of Flammabil-ity of Chemicals (Vapors and Gases)E 1232 Test Method for Temperature Limit of Flammabilityof Chemicals3. Terminology3.1 Definition:3.1.1 flash pointthe lowest temperature, corrected to apressure of 760 mm Hg (101.3 kPa) (1013 mbar) at whichapplica
11、tion of an ignition source causes the vapors of aspecimen to ignite under specified conditions of test.4. Summary of Test Method4.1 The specimen is placed in a closed cup and in the smallscale method equilibrated at a test temperature, in the Pensky-Martens Method heated at a controlled rate with st
12、irring, and inthe Tag Method also heated at a controlled rate but withoutstirring. A small flame is directed into the vapor space of eachcup at specified intervals, with simultaneous interruption ofstirring in the Pensky-Martens Method, to determine whether aflash occurs or not. In Test Method D 394
13、1, the specimen is1This test method is under jurisdiction of ASTM Committee E27 on HazardPotential of Chemicals and is the direct responsibility of Subcommittee E27.04 onFlammability and Ignitability of Chemicals.Current edition approved Jan. 15, 2007. Published March 2007. Originallyapproved in 198
14、4. Last previous edition approved in 2006 as E 50206a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdr
15、awn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.heated at a slower rate than in the other controlled heatingmethods, maintaining a small temperature differential betweenbath and specimen.5. Significance and Use5.1 The flash point
16、 measures the response of the sample toheat and flame under controlled laboratory conditions. It isonly one of a number of properties that must be considered inassessing the overall flammability hazard of a material.5.2 As a result of physical factors inherent in the apparatusand procedure, the clos
17、ed cup flash point does not necessarilyrepresent the minimum temperature at which a material canevolve flammable vapors, and the absence of a flash point doesnot guarantee nonflammability (see Appendix X1 and Appen-dix X2).5.3 Flash point is used in shipping and safety regulations todefine flammable
18、 and combustible materials. Test MethodsD 56, D 93, and D 3278 are specified as test methods fordetermining the flash point of these materials.5.4 If the process or handling conditions dictate the usage ofa flammable material at temperatures ranging upward from 5 to10C below the closed-cup flash poi
19、nt, then a flammable vapormight be present above the liquid. In such cases, it may bemore appropriate to use the temperature limit of flammability(as determined by Test Method E 1232) instead of flash point.5.5 Small scale methods involving equilibrium proceduresand only one flame pass per specimen
20、are preferred.6. Interferences6.1 Incorrect flash points can be obtained when testingchemicals corrosive to the materials of construction of the cup.(For example, certain amines and acid chlorides react with thestandard aluminum small scale cup causing erroneously lowflash points, perhaps due to hyd
21、rogen formation.) Cups em-ploying alternative materials of construction, electroplating orplastic coating can provide corrosion resistance. Results innon-standard cups, particularly in non-equilibrium tests, maydiffer slightly from those obtained in this test method.7. Apparatus7.1 Tag Closed-Cup Te
22、ster, including thermometers, shallbe as shown in Test Methods D 56 and D 3941.7.2 Penksy-Martens Closed-Cup Tester, including ther-mometers, shall be as shown in Test Methods D93.7.3 Small scale Closed Tester, including thermometers, shallbe as shown in Test Methods D 3278 or D 3828.NOTE 1Some auto
23、matic flash point testers may save testing time andpermit the use of small samples. If automatic testers are used, the usermust be certain that all instructions for calibration and operation arefollowed to ensure that the results are equivalent to those obtained on theASTM standard equipment. For re
24、gulation purposes or in cases of dispute,the flash point as determined on the manual tester shall be the acceptedvalue.NOTE 2ASTM thermometers 33C or 33F may be used in the TagTester instead of those specified in Test Method D56when conductingtests at temperatures below 10C (14F). Slight stem correc
25、tions may benecessary and care should be taken to avoid freezing the mercury in thethermometer by cooling below 40C (40F).7.4 Shield, as described in Test Method D 3941 or Test Method D 1310.8. Hazards8.1 Toxicity of Chemical and Combustion Products:8.1.1 Isolate or control operations on toxic or co
26、rrosivematerials to prevent exposure to any personnel.8.1.2 Since flash point tests are conducted in still air, the useof forced circulation for removal of toxic or nuisance fumes orcombustion products is restricted. However, a laboratory fumehood equipped with an exhaust damper that can be complete
27、lyclosed provides an ideal location for maintaining draft-freeconditions and provides the ability to readily exhaust danger-ous vapors and combustion products when necessary.8.1.3 Use respiratory and splash protective devices as ap-propriate with toxic or corrosive materials. In most cases,approved
28、cartridge respirators are adequate respiratory protec-tion for the concentrations normally encountered in flash-pointtesting. Certain toxic or unusual materials, however, mayrequire an air-supplied respirator and extreme cases mayrequire complete protective coverage such as an air-suppliedplastic su
29、it. (Two examples of the latter type of material aredimethyl sulfate and pure mercaptans.) Tests on these highlytoxic or obnoxious materials may also be conducted in com-pletely isolated, closed systems, such as glove boxes. In thiscase, procedures should ensure an uncontaminated air systemin the bo
30、x, and should prevent a buildup of vapors from thematerial under test.8.2 Dry Ice Use:8.2.1 Exercise care in the use of dry ice for sample andapparatus cooling. Avoid contact with dry ice to preventfrostbite. Glass bottles or vials of chemicals should not beplaced directly in dry ice or dry ice bath
31、s because of thepossibility of breakage due to thermal shock.8.3 Tests of Explosives and Propellants:8.3.1 Flash tests should not be conducted on potential orknown explosive or propellant materials without completeprior knowledge that burning will not result in propagation toan explosive decompositi
32、on. Properly barricaded or remotelyoperated automatic testers should be used if precise flash pointsare needed.8.4 Pyrophoric Materials:8.4.1 Flash point apparatus is not applicable for the evalu-ation of pyrophoric materials and should not be used for thispurpose.9. Preparation of Sample9.1 Obtain
33、samples representative of the batch under test.Test Method D 270 can be used as a reference on samplingtechniques. With mixtures and with samples containing impu-rities, take care to avoid the loss of volatile components duringsampling and handling for testing. When heating viscous orsolid materials
34、 for ease of pouring, samples must be held attemperatures below, or as close as possible to, those specifiedin the various test methods. Discard samples from leaking orcontaminated containers. Samples that are hygroscopic shouldnot be exposed to moisture or moist air.9.2 Samples should not be stored
35、 in plastic (polyethylene,polypropylene, etc.) bottles, since volatile materials may dif-fuse through the walls of the bottle.E50207210. Preparation of Apparatus10.1 Support the appropriate flash-point tester on a level,steady work surface in a draft-free location. If a draft-freelocation is not ava
36、ilable, use a shield surrounding the tester onthree sides. The shield should be approximately 460 mm (18in.) wide and 610 mm (24 in.) high.NOTE 3An area capable of being partially darkened is advantageoussince it aids in the detection of the relatively nonluminous flamessometimes encountered in flas
37、h-point testing.NOTE 4Test Method D 1310 gives a design for a draft shield suitablefor standard flash-point testers.11. Calibration11.1 Check the condition and operation of the Tag, Pensky-Martens and small scale testers as specified in Test MethodsD 56, D 93, D 3278, or D 3828, respectively.12. Pro
38、cedure12.1 Follow the procedures outlined in Test Methods D56or D 3941 (Tag Closed Cup), D 3278 or D 3827 (Small scaleClosed Cup), and D93(Pensky Martens Closed Cup), as isnecessary. Certain explanatory notes and procedure modifica-tions not contained in the individual methods are given below.Occasi
39、onally, particularly near the temperature of the actualflash point, the application of the test flame will cause a halo ortest flame enlargement that should be ignored. In some casesthis test flame enlargement will not lead to a flash point on anincrease in temperature.12.2 For liquids with a viscos
40、ity less than 5.8 3 106m2/s(5.8 cSt) at 38C (100F), or 9.5 3 106m2/s (9.5 cSt) at 25C(77F), observe the following:NOTE 5The first viscosity threshold point is stated either as“5.8 3 106m2/s (5.8 cSt) at 100F (38C)”, or as “5.5 3 106m2/s (5.5cSt) at 40C (104F), in different flash point test standards
41、. The choice isindicative of only the unit system preferred by individual test standards. Inpractice the two forms are considered equivalent.12.2.1 If the flash point is below 93C (200F), use thesmall scale (Test Method D 3278 or D 3828) or Tag (TestMethod D56) apparatus and procedures.12.2.2 If the
42、 flash point is 93C (200F) or above, use thesmall scale (Test Method D 3828) or Pensky-Martens (TestMethods D93) apparatus and procedures.NOTE 6The electric heaters on some Tag Testers may be of insuffi-cient capacity to maintain the specified heating rates when operating in theupper ranges of this
43、practice. Heat input can be increased slightly by usinga variable transformer to increase the voltage slightly on the heaters.Insulation can be applied to the exterior of the bath to reduce heat losses.NOTE 7With low temperature operation in the small scale methods,equilibrium may be difficult to ma
44、intain due to heating by naturalconvection. It, therefore, will be necessary to cool the cup and samplebelow the anticipated flash point before specimen introduction (see TestMethods D 3278).NOTE 8In the Tag Method (Test Method D56), natural warming ratessometimes exceed 1C (2F)/min. These rates can
45、 be reduced by insulat-ing the outside of the bath container. A laboratory refrigerated circulatormay be used. One advantage of this system is that circulation of therefrigerant bath with the system gradually warming up can serve as acontrol on heating rate.NOTE 9With low-temperature operation in th
46、e Tag and Small scaleMethods, difficulties can be created by the formation of frost on thesurface of the tester. If precise flash points are needed in the temperaturerange where frost conditions are encountered, tests can be conducted in adry box or a room of very low humidity.When ice formation on
47、the lid andcover parts cannot be avoided, the results will be unreliable. Sticking ofthe slide due to ice formation can be minimized by carefully lubricatingthe slide with a high vacuum silicone lubricant. Portions of the cover andslide in the vicinity of the pilot flame and openings should be wiped
48、 freeof frost just prior to the initial flame insertion at 5C (10F) below theflash point.12.3 For liquids with a viscosity equal to or greater than5.8 3 106m2/s (5.8 cSt) at 38C (100F), or 9.5 3 106m2/s(9.5 cSt) at 25C (77F) and less than 15 3 103m2/s (150 St)at 25C (77F), and a flash point below 11
49、0C (230F), thefollowing procedure applies:12.3.1 Use of Pensky-Martens Method (Test Methods D93)or the small scale (Test Method D 3278 or D 3828) apparatusand procedure.12.4 For liquids with a viscosity equal to or greater than5.8 3 106m2/s (5.8 cSt) at 38C (100F) or 9.5 3 106m2/s(9.5 cSt) at 25C (77F) and a flash point of 93C (200F) orabove, the following procedure applies:12.4.1 Use the Pensky-Martens (Test Methods D93) andthe small scale (Test Method D 3828) apparatus and procedure.NOTE 10Testing time may be reduced by
