FINAL DRAFT UGANDA 
STANDARD  
  FDUS 2040  
First Edition  
2018-mm-dd  
 
  
This Final Draft Uganda Standard, FDUS 2040:2018, i s based on ASTM  D92  – 18 ,
Standard Test Method for Flash and Fire Points by C leveland Open Cup Tester,
Copyright ASTM International, 100 Barr Harbor Drive , West Conshohocken, PA 
19428, USA, pursuant to license with ASTM Internati onal . Reference number 
FDUS 2040: 201 8
© UNBS 201 8
  
Standard Test Method for Flash and Fire Points by C leveland 
Open Cup Tester  
 D92 – 18          FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     ii  
 Compliance with this standard does not, of itself c onfer immunity from legal obligations 
A Uganda Standard does not purport to include all n ecessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2018 
All rights reserved. Unless otherwise specified, no  part of this publication may be reproduced or util ized in any form 
or by any means, electronic or mechanical, includin g photocopying and microfilm, without prior written  permission 
from UNBS. 
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The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala 
Uganda 
Tel: +256 417 333 250/1/2 
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E-mail: info@unbs.go.ug  
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  D92 – 18         FDUS 2040: 2018  
 
 
© UNBS 2018  – All rights reserved    iii  Foreword 
Uganda National Bureau of Standards (UNBS) is a par astatal under the Ministry of Trade, Industry and 
Cooperatives established under Cap 327, of the Laws  of Uganda, as amended.  UNBS is mandated to co-ord inate 
the elaboration of standards and is  
(a) a member of International Organisation for Stan dardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentar ius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried o ut through Technical Committees. A Technical Commit tee is 
established to deliberate on standards in a given f ield or area and consists of key stakeholders inclu ding 
government, academia, consumer groups, private sect or and other interested parties.  
Draft Uganda Standards adopted by the Technical Com mittee are widely circulated to stakeholders and th e 
general public for comments. The committee reviews the comments before recommending the draft standard s for 
approval and declaration as Uganda Standards by the  National Standards Council. 
The committee responsible for this document is Tech nical Committee UNBS/TC 16/SC 1, Petroleum and 
petrochemical products . 
Wherever the words, “ASTM Standard" appear, they sh ould be replaced by "Uganda Standard." 
 
 FINAL DRAFT UGANDA STANDARD FDUS 2040: 2018  
 
Designation: D92 – 18   
 
This Final Draft Uganda Standard, FDUS 2040:2018, i s based on ASTM  D92– 18, Standard Test Method for Flash and Fire 
Points by Cleveland Open Cup Tester ,    Copyright ASTM International, 100 Barr Harbor Drive , West Conshohocken, PA 19428, 
USA, pursuant to license with ASTM International.  
 
 
 
© UNBS 2018  – All rights reserved     4  
 
 Standard Test Method for  
Flash and Fire Points by Cleveland Open Cup Tester  1 
 
American Association State  
Highway and Transportation Officials Standard  
AASHTO No.: T48 DIN 51 376 
 
This standard is issued under the fixed designation  D92; the number immediately following the designat ion indicates the year of original adoption or, in the 
case of revision, the year of last revision. A numb er in parentheses indicates the year of last reappr oval. A superscript epsilon ( ε) indicates an editorial change 
since the last revision or reapproval.  
 
This standard has been approved for use by agencies  of the U.S. Department of Defense.  
INTRODUCTION  
This flash point and fire point test method is a dy namic method and depends on definite rates of tempe rature increases to 
control the precision of the test method. Its prima ry use is for viscous materials having flash point of 79  °C (175  °F) and 
above. It is also used to determine fire point, whi ch is a temperature above the flash point, at which  the test specimen will 
support combustion for a minimum of 5  s. Do not confuse this test method with Test Method  D4206 , which is a sustained 
burning test, open cup type, at a specific temperat ure of 49  °C (120  °F).  
Flash point values are a function of the apparatus design, the condition of the apparatus used, and th e operational procedure 
carried out. Flash point can therefore only be defi ned in terms of a standard test method, and no gene ral valid correlation can 
be guaranteed between results obtained by different  test methods, or with test apparatus different fro m that specified. 
 
1.  Scope *  
 
1.1  This test method describes the determination o f the flash point and fire point of petroleum produ cts by a manual 
Cleveland open cup apparatus or an automated Clevel and open cup apparatus.  
NOTE 1—The precisions for fire point were not determined  in the current interlaboratory program. Fire point  is a parameter that is not 
commonly specified, although in some cases, knowled ge of this flammability temperature may be desired.  
1.2  This test method is applicable to all petroleu m products with flash points above 79  °C (175  °F) and below 400  °C 
(752  °F) except fuel oils.  
NOTE 2—This test method may occasionally be specified fo r the determination of the fire point of a fuel oil . For the determination of the 
flash points of fuel oils, use Test Method D93 . Test Method D93  should also be used when it is desired to determin e the possible presence of 
small but significant concentrations of lower flash  point substances that may escape detection by Test  Method D92. Test Method D1310  can 
be employed if the flash point is known to be below  79  °C (175  °F). 
1.3  The values stated in SI units are to be regard ed as the standard.   
1.3.1  Exception— The values given in parentheses are for information  only. 
1.4  WARNING —Mercury has been designated by many regulatory age ncies as a hazardous substance that can cause 
serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and cor rosive to materials. Use 
                                                 
1 This test method is under the jurisdiction of ASTM  Committee D34  on Waste Management   and is the direct responsibi lity of Subcommittee D34.01.01  on 
Planning for Sampling. 
Current edition approved Nov. 1, 2012. Published De cember 2012. Originally approved in 1998. Last prev ious edition approved in 2003 as D6323  – 98 
(2003), which was withdrawn in June 2012 and reinst ated in August 2012. DOI: 10.1520/D6323-12E01.  D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    5 Caution when handling mercury and mercury-containin g products. See the applicable product Safety Data Sheet (SDS) for 
additional information. The potential exists that s elling mercury or mercury-containing products, or b oth, is prohibited by 
local or national law. Users must determine legalit y of sales in their location. 
1.5  This standard does not purport to address all of th e safety concerns, if any, associated with its use.  It is the 
responsibility of the user of this standard to esta blish appropriate safety, health, and environmental  practices and determine 
the applicability of regulatory limitations prior t o use. For specific warning statements, see 6.4 , 7.1 , 11.1.3 , and 11.2.4 . 
1.6  This international standard was developed in accord ance with internationally recognized principles on standardization 
established in the Decision on Principles for the D evelopment of International Standards, Guides and R ecommendations 
issued by the World Trade Organization Technical Ba rriers to Trade (TBT) Committee.  
 
2.  Referenced Documents  
2.1  ASTM Standards: 2  
D93    
D140    
D1310    
D4057    
D4177    
D4206    
E1    
E300    
2.2  Energy Institute Standard: 3  
Specifications for IP Standard Thermometers    
2.3  ISO Standards: 4  
Guide  34   General requirements for the competence of refere nce material producers 
Guide  35   Reference materials—General and statistical princ iples for certification 
 
3.  Terminology  
 
3.1  Definitions:  
3.1.1  dynamic , adj —in petroleum products , the condition where the vapor above the test spec imen and 
the test specimen are not in temperature equilibriu m at the time that the ignition source is applied. 
3.1.1.1  Discussion —This is primarily caused by the heating of the tes t specimen at the constant 
prescribed rate with the vapor temperature lagging behind the test specimen temperature. 
3.1.2  fire point , n—in flash point test methods , the lowest temperature of the test specimen, adju sted to 
account for variations in atmospheric pressure from  101.3 kPa, at which application of an ignition sou rce 
causes the vapors of the test specimen to ignite an d sustain burning for a minimum of 5 s under specif ied 
conditions of test. 
3.1.3  flash point , n—in flash point test methods , the lowest temperature of the test specimen, adju sted 
to account for variations in atmospheric pressure f rom 101.3 kPa, at which application of an ignition 
source causes the vapors of the test specimen to ig nite under specified conditions of test. 
                                                 
2 For referenced ASTM standards, visit the ASTM webs ite, www.astm.org, or contact ASTM Customer Service  at service@astm.org. For Annual Book of 
ASTM Standards  volume information, refer to the standard's Docume nt Summary page on the ASTM website. 
3 Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR, U.K., http://www.energyinst.o rg. 
4 Available from American National Standards Institu te (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     6  
  
4.  Summary of Test Method  
 
4.1  Approximately 70 mL of test specimen is filled  into a test cup. The temperature of the test 
specimen is increased rapidly at first and then at a slower constant rate as the flash point is approa ched. 
At specified intervals, a test flame is passed acro ss the cup. The flash point is the lowest liquid 
temperature at which application of the test flame causes the vapors of the test specimen of the sampl e to 
ignite. To determine the fire point, the test is co ntinued until the application of the test flame cau ses the 
test specimen to ignite and sustain burning for a m inimum of 5 s. 
 
5.  Significance and Use  
 
5.1  The flash point 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 that should be 
considered in assessing the overall flammability ha zard of a material. 
5.2  Flash point is used in shipping and safety reg ulations to define flammable and combustible 
materials. Consult the particular regulation involv ed for precise definitions of these classifications . 
5.3  Flash point can indicate the possible presence  of highly volatile and flammable materials in a 
relatively nonvolatile or nonflammable material. Fo r example, an abnormally low flash point on a test 
specimen of engine oil can indicate gasoline contam ination. 
5.4  This test method shall be used to measure and describe the properties of materials, products, or 
assemblies in response to heat and a test flame und er controlled laboratory conditions and shall not b e 
used to describe or appraise the fire hazard or fir e risk of materials, products, or assemblies under actual 
fire conditions. However, results of this test meth od may be used as elements of a fire risk assessmen t 
that takes into account all of the factors that are  pertinent to an assessment of the fire hazard of a  
particular end use. 
5.5  The fire point is one measure of the tendency of the test specimen to support combustion. 
 
6.  Apparatus  
 
6.1  Cleveland Open Cup Apparatus (manual)— This apparatus consists of the test cup, heating pl ate, 
test flame applicator, heater, and supports describ ed in detail in the Annex A1 . The assembled manual 
apparatus, heating plate, and cup are illustrated i n Figs. 1-3 , respectively. Dimensions are listed with the 
figures. 
  D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    7 
 
 
FIG. 1 Cleveland Open Cup Apparatus  
 
 
 
 
   millimetres inches 
   min max min max 
A 6 7 0.236 0.276 
B 0.5 1.0 0.020 0.039 
C 6 7 0.236 0.276  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     8  
 D—Diameter 55 56 2.165 2.205 
E—Diameter 69.5 70.5 2.736 2.776 
F—Diameter 146 159 5.748 6.260 
FIG. 2 Heating Plate  
 
 
 
FIG. 3  Cleveland Open Cup  
6.2  Cleveland Open Cup Apparatus (automated)— This apparatus is an automated flash point 
instrument that shall perform the test in accordanc e with Section 11  Procedure. The apparatus shall use 
the test cup with the dimensions as described in Annex A1  and the application of the test flame shall be 
as described in Annex A1 . 
6.3  Temperature Measuring Device— A thermometer having the range as shown below and 
conforming to the requirements prescribed in Specif ication E1  or in the Specifications for IP Standard 
Thermometers, or an electronic temperature measurin g device, such as a resistance thermometer or 
thermocouple. The device shall exhibit the same tem perature response as the mercury thermometers. 
 
   Thermometer Number 
Temperature Range ASTM IP 
–6 °C to +400 °C 11C 28C 
20 °F to 760 °F 11F 
6.4  Test Flame— Natural gas (methane) flame and bottled gas (butane , propane) flame have been 
found acceptable for use as the ignition source. Th e gas flame device is described in detail in Annex A1 . 
(Warning— Gas pressure supplied to the apparatus must not be allowed to exceed 3 kPa (12 in.) of water 
pressure.) 
 
7.  Reagents and Materials   D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    9  
7.1  Cleaning Solvents— Use suitable technical grade solvent capable of cle aning out the test specimen 
from the test cup and drying the test cup. Some com monly used solvents are toluene and acetone. 
(Warning— Toluene, acetone, and many solvents are flammable. Health hazard. Dispose of solvents and 
waste material in accordance with local regulations .) 
 
8.  Sampling  
 
8.1  Obtain a sample in accordance with the instruc tions given in Practices D140 , D4057 , D4177  or 
E300 . 
8.2  At least 70 mL of sample is required for each test. Refer to Practice D4057 . 
8.3  Erroneously high flash points may be obtained if precautions are not taken to avoid the loss of 
volatile material. Do not open containers unnecessa rily; this will prevent loss of volatile material a nd 
possible introduction of moisture. Do not make a tr ansfer of the sample unless the sample temperature is 
at least 56 °C (100 °F) below the expected flash po int. When possible, flash point should be the first  test 
performed on a sample and the sample should be stor ed at low temperature. 
NOTE 3—Typical sample storage temperature is normal room  temperature or lower. 
8.4  Do not store samples in gas-permeable containe rs since volatile material may diffuse through the 
walls of the enclosure. Samples in leaky containers  are suspect and not a source of valid results. 
8.5  Light hydrocarbons may be present in the form of gases, such as propane or butane, and may not 
be detected by testing because of losses during sam pling and filling of the test cup. This is especial ly 
evident on heavy residuums or asphalts from solvent  extraction processes. 
8.6  Samples of very viscous materials can be warme d until they are reasonably fluid before they are 
tested. However, no sample shall be heated more tha n is absolutely necessary. It shall never be heated  
above a temperature of 56 °C (100 °F) below its exp ected flash point. When the sample has been heated 
above this temperature, allow the sample to cool un til it is at least 56 °C (100 °F) below the expecte d 
flash point before transferring. 
NOTE 4—Typically, the sample containers for these types of samples will remain closed during the warming pr ocess. 
8.7  Samples containing dissolved or free water can  be dehydrated with calcium chloride or by filterin g 
through a qualitative filter paper or a loose plug of dry absorbent cotton. Samples of very viscous 
materials can be warmed until they are reasonably f luid before they are filtered, but they shall not b e 
heated for prolonged periods or above a temperature  of 56 °C (100 °F) below its expected flash point. 
NOTE 5—If the sample is suspected of containing volatile  contaminants, the treatment described in 8.6  and 8.7  should be omitted. 
 
9.  Preparation of Apparatus  
 
9.1  Support the manual or automated apparatus on a  level steady surface, such as a table. 
9.2  Tests are to be performed in a draft-free room  or compartment. Tests made in a laboratory hood or  
in any location where drafts occur are not to be re lied upon. 
NOTE 6—A draft shield is recommended to prevent drafts f rom disturbing the vapors above the test cup. This shield should cover at least 
three sides of the test cup vicinity. Some apparatu s may already include a built-in draft shield. 
NOTE 7—With some samples whose vapors or products of pyr olysis are objectionable, it is permissible to plac e the apparatus along with 
a shield into a hood, the draft of which is adjuste d so that the vapors may be withdrawn without causi ng air currents over the test cup during 
the final 56 °C (100 °F) rise in temperature prior to the flash point. 
9.3  Wash the test cup with the cleaning solvent to  remove any test specimen or traces of gum or 
residue remaining from a previous test. If any depo sits of carbon are present, they should be removed 
with a material such as a very fine grade of steel wool. Ensure that the test cup is completely clean and  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     10  
 dry before using again. If necessary, flush the tes t cup with cold water and dry for a few minutes ove r an 
open flame or a hot plate to remove the last traces  of solvent and water. Cool the test cup to at leas t 56 °C 
(100 °F) below the expected flash point before usin g. 
9.4  Support the temperature measuring device in a vertical position with the bottom of the device 
located 6.4  mm  ± 0.5  mm ( 1/4  in.  ± 1/50   in.) up from the bottom of the inside of the test  cup and located at 
a point halfway between the center and the side of the test cup on a diameter perpendicular to the arc  (or 
line) of the sweep of the test flame and on the sid e opposite to the test flame applicator mounting 
position. It is permissible for electronic temperat ure measuring devices to be mounted in a non-vertic al 
position provided that performance is in accordance  with the requirements given in 6.3 . 
NOTE 8—The immersion line engraved on the ASTM or IP the rmometer will be 2 mm ± 0.5 mm ( 5/64   in.  ± 1/50   in.) below the level of the 
rim of the cup when the thermometer is properly pos itioned. 
NOTE 9—Some automated apparatus is capable of positionin g the temperature measuring device automatically. R efer to the 
manufacturer's instructions for proper installation  and adjustment. 
9.5  Prepare the manual apparatus or the automated apparatus for operation according to the 
manufacturer's instructions for calibrating, checki ng, and operating the equipment. 
 
10.  Calibration and Standardization  
 
10.1  Adjust the automated flash point detection sy stem, when used, according to the manufacturer's 
instructions. 
10.2  Calibrate the temperature measuring device ac cording to the manufacturer's instructions. 
10.3  Verify the performance of the manual apparatu s or the automated apparatus at least once per year  
by determining the flash point of a certified refer ence material (CRM), such as those listed in Annex A2 , 
which is reasonably close to the expected temperatu re range of the samples to be tested. The material 
shall be tested according to the procedure of this test method and the observed flash point obtained i n 
11.1.10  or 11.2.5  shall be corrected for barometric pressure (see Se ction 12 ). The flash point obtained 
shall be within the limits stated in Table A2.1  for the identified CRM or within the limits calcul ated for 
an unlisted CRM (see Annex A2 ). 
10.4  Once the performance of the apparatus has bee n 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 (s ee Annex A2 ). 
NOTE 10—The verification fluid is a material with a pred etermined, interlaboratory tested, flash point temp erature that is used to verify 
proper operation of the apparatus. Calibration is u ndertaken by the operator according to the apparatu s manufacturer’s instructions should 
the result of the verification be outside the state d reproducibility. 
10.5  When the flash point obtained is not within t he limits stated in 10.3  or 10.4 , check the condition 
and operation of the apparatus to ensure conformity  with the details listed in Annex A1 , especially in 
regard to the position of the temperature measuring  device, the application of the test flame, and the  
heating rate. After adjustment of the apparatus, re peat the test with a fresh test specimen (see 10.3 ) with 
special attention to the procedural details prescri bed in Section 11 . 
 
11.  Procedure  
 
11.1  Manual Apparatus:  
11.1.1  Fill the test cup with the sample so that t he top of the meniscus of the test specimen is leve l 
with the filling mark, and position the test cup on  the center of the heating plate. The temperature o f the 
test cup and the sample shall not exceed 56  °C (100 °F) below the expected flash point. If too much test  D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    11  specimen has been added to the cup, remove the exce ss using a syringe or similar device for withdrawal  
of fluid. However, if there is test specimen on the  outside of the test cup, empty, clean, and refill it. 
Destroy any air bubbles or foam on the surface of t he test specimen with a sharp knife or other suitab le 
device and maintain the required level of test spec imen. If a foam persists during the final stages of  the 
test, terminate the test and disregard any results.  
NOTE 11—Initially the test cup may be filled below the f illing mark to allow for thermal expansion of the s ample. 
11.1.2  Solid material shall not be added to the te st cup. Solid or viscous samples shall be heated un til 
they are fluid before being poured into the test cu p; however, the temperature of the sample during 
heating shall not exceed 56 °C (100 °F) below the e xpected flash point. 
11.1.3  Light the test flame and adjust it to a dia meter of 3.2  mm to 4.8 mm ( 1/8  in. to 3/16    in.) or to the 
size of the comparison bead, if one is mounted on t he apparatus (see Annex A1 ). ( Warning— Gas 
pressure supplied to the apparatus must not be allo wed to exceed 3 kPa (12 in.) of water pressure.) 
(Warning— Exercise care when using a gas test flame. If it sh ould be extinguished it will not ignite the 
vapors in the test cup, and the gas for the test fl ame that then enters the vapor space can influence the 
result.) ( Warning— The operator shall exercise care and take appropria te safety precautions during the 
initial application of the test flame since test sp ecimens containing low-flash material can give an 
abnormally strong flash when the test flame is firs t applied.) ( Warning— As a safety practice, it is 
strongly advised, when using automated or manual ap paratus, before heating the test cup and specimen, 
to pass the test flame across the specimen in the t est cup to check for the presence of unexpected vol atile 
material.) ( Warning— The operator shall exercise care and take appropria te safety precautions during the 
performance of this test method. The temperatures a ttained during this test, up to 400 °C (752 °F), ar e 
considered hazardous.) 
NOTE 12—Some further preliminary test flame applications  during the initial heating phase may be useful in detecting whether 
unexpected volatile material is present in the samp le. A typical interval is at the beginning of the i nitial heating phase and then every 10 °C 
up to the standard test flame application temperatu re. See 11.1.5 . 
11.1.4  Apply heat initially at such a rate that th e temperature as indicated by the temperature 
measuring device increases 5  °C to 17 °C (9 °F to 30 °F)/min. When the test spec imen temperature is 
approximately 56 °C (100 °F) below the expected fla sh point, decrease the heat so that the rate of 
temperature rise during the last 28 °C (50 °F) befo re the flash point is 5 °C to 6 °C (9 °F to 11 °F)/ min. 
NOTE 13—With low flash point material or with highly vis cous material, it is advised to use the 5 °C/min to  6 °C/min heating rate from 
the start of the test to the end. 
11.1.5  Apply the test flame when the temperature o f the test specimen is approximately 28 °C below 
the expected flash point and each time thereafter a t a temperature reading that is a multiple of 2 °C.  Pass 
the test flame across the center of the test cup at  right angles to the diameter, which passes through  the 
temperature measuring device. With a smooth, contin uous motion, apply the test flame either in a strai ght 
line or along the circumference of a circle having a radius of at least 150 mm   ± 1 mm (6.00 in.  ± 0.039 
in.). The center of the test flame shall move in a horizontal plane not more than 2 mm ( 5/64   in.) above the 
plane of the upper edge of the test cup and passing  in one direction only. At the time of the next tes t 
flame application, pass the test flame in the oppos ite direction of the preceding application. The tim e 
consumed in passing the test flame across the test cup in each case shall be approximately 1 s ± 0.1 s . 
NOTE 14—Some automated apparatus pass the test flame in one single direction. Apparatus that operate in thi s manner will typically shut 
off the test flame gas after each application, retu rn to the starting position without creating a draf t near and over the test cup, and the test 
flame will be relighted in such a manner that no fu el gas enters the cup vapor space before the next t est application. 
NOTE 15—When determining the flash point of asphalt, it is recommended to carefully move fully to one side,  such as with a spatula, any 
surface film formed before each application of the ignition source. Available data indicate that highe r flash point is observed for asphalt 
samples when surface film formed is not moved aside , compared to the flash point observed when the sur face film is moved aside prior to 
the application of the ignition source. 
NOTE 16—An alternative to the moving aside of the formed  surface film can be found in Appendix X1 .  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     12  
 11.1.6  During the last 28 °C (50 °F) rise in tempe rature prior to the expected flash point, care shal l be 
taken to avoid disturbing the vapors in the test cu p with rapid movements or drafts near the test cup.  
11.1.7  When a foam persists on top of the test spe cimen during the last 28 °C (50 °F) rise in 
temperature prior to the expected flash point, term inate the test and disregard any results. 
11.1.8  Meticulous attention to all details relatin g to the test flame, size of the test flame, rate o f 
temperature increase, and rate of passing the test flame over the test specimen is required for proper  
results. 
11.1.9  When testing a sample whose expected flash point temperature is not known, bring the test 
specimen in the test cup to a temperature no greate r than 50 °C (122 °F), or if the sample required 
heating to be transferred into the test cup, bring the test specimen in the test cup to that temperatu re. 
Apply the test flame, in the manner described in 11.1.5 , beginning at least 5 °C (9 °F) above the starting  
temperature. Continue heating the test specimen at 5 °C to 6 °C (9 °F to 11  °F)/min and testing the test 
specimen every 2 °C (5 °F) as described in 11.1.5  until the flash point is obtained. 
NOTE 17—Flash point results determined in an unknown exp ected flash point mode should be considered approxi mate. This value can be 
used as the expected flash point when a fresh speci men is tested in the standard mode of operation. 
11.1.10  Record, as the observed flash point, the r eading on the temperature measuring device at the 
time the test flame causes a distinct flash in the interior of the test cup. 
11.1.10.1  The sample is deemed to have flashed whe n a large flame appears at any point on the 
surface of the test specimen and instantaneously pr opagates itself over the surface of the test specim en. 
11.1.11  The application of the test flame can caus e a blue halo or an enlarged flame prior to the act ual 
flash point. This is not a flash point and shall be  ignored. 
11.1.12  When a flash point or fire point is detect ed during any preliminary test flame application, o r 
on the first application of the test flame, see 11.1.5 , the test shall be discontinued, the result discar ded, 
and the test repeated with a fresh test specimen. T he first application of the test flame with the fre sh test 
specimen shall be at least 28 °C (50 °F) below the temperature found when the flash point was detected  
under the conditions in 11.1.12 . 
11.1.13  When the apparatus has cooled down to a sa fe handling temperature, less than 60 °C (140 °F), 
remove the test cup and clean the test cup and the apparatus as recommended by the manufacturer. 
NOTE 18—Exercise care when cleaning the apparatus so as not to damage or dislocate the automated flash dete ction system, when used, 
or temperature measuring device. See the manufactur er's instructions for proper care and maintenance. 
11.1.14  To determine the fire point, continue heat ing the test specimen after recording the flash poi nt 
such that the test specimen temperature increases a t a rate of 5 °C to 6 °C (9 °F to 11 °F)/min. Conti nue 
the application of the test flame at 2 °C (5 °F) in tervals until the test specimen ignites and sustain s 
burning for a minimum of 5 s. Record the temperatur e of the test specimen when the test flame, which 
caused the test specimen to ignite was applied. Sus tain burning as the observed fire point of the test  
specimen. 
11.1.15  When the apparatus has cooled down to a sa fe handling temperature, less than 60 °C (140 °F), 
remove the test cup and clean the test cup and the apparatus as recommended by the manufacturer. 
11.2  Automated Apparatus:  
11.2.1  The automated apparatus shall be capable of  performing the procedure as described in 11.1 , 
including control of the heating rate, application of the test flame, detection of the flash point, or  fire 
point, or both, and recording the flash point or fi re point, or both. 
11.2.2  Fill the test cup with the sample so that t he top of the meniscus of the test specimen is leve l 
with the filling mark, and position the test cup on  the center of the heating plate. The temperature o f the 
test cup and the sample shall not exceed 56  °C (100 °F) below the expected flash point. If too much test 
specimen has been added to the cup, remove the exce ss using a syringe or similar device for withdrawal   D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    13  of fluid; however, if there is test specimen on the  outside of the test cup, empty, clean, and refill it. 
Destroy any air bubbles or foam on the surface of t he test specimen with a sharp knife or other suitab le 
device, and maintain the required level of test spe cimen. If a foam persists during the final stages o f the 
test, terminate the test, and disregard any results . 
NOTE 19—Initially the test cup may be filled below the f illing mark to allow for thermal expansion of the s ample. 
11.2.3  Solid material shall not be added to the te st cup. Solid or viscous samples shall be heated un til 
they are fluid before being poured into the test cu p; however, the temperature of the sample during 
heating shall not exceed 56 °C (100 °F) below the e xpected flash point. 
11.2.4  Light the test flame, when necessary, and a djust it to a diameter of 3.2 mm to 4.8 mm ( 1/8  in. to 
3/16   in.) or to the size of the comparison bead, if on e is mounted on the apparatus. ( Warning— Gas 
pressure supplied to the apparatus must not be allo wed to exceed 3 kPa (12 in.) of water pressure.) 
(Warning— Exercise care when using a gas test flame. If it sh ould be extinguished it will not ignite the 
vapors in the test cup, and the gas for the test fl ame that then enters the vapor space can influence the 
result.) ( Warning— The operator shall exercise care and take appropria te safety precautions during the 
initial application of the test flame since test sp ecimens containing low-flash material can give an 
abnormally strong flash when the test flame is firs t applied.) ( Warning— The operator shall exercise care 
and take appropriate safety precautions during the performance of this test method. The temperatures 
attained during this test, up to 400 °C (752 °F), a re considered hazardous.) 
NOTE 20—Some automated apparatus can perform preliminary  test flame applications during the initial heating  phase. 
NOTE 21—Some automated apparatus can light the test flam e automatically and the size of the flame is preset . 
NOTE 22—Test samples containing >1 % silicones can creat e an insulating deposit on ionization ring flash de tectors, as used on most 
automated apparatus, that can lead to erroneous res ults. If test samples are known to contain silicone s, the use of the manual test is 
recommended. Ionization ring flash detectors suspec ted of giving erroneous results can be cleaned usin g a suitable solvent. 
11.2.5  Start the automated apparatus according to the manufacturer's instructions. The apparatus shal l 
follow the procedural details described in 11.1.4  through 11.1.15 . 
 
12.  Calculations  
 
12.1  Observe and record the ambient barometric pre ssure (see Note 23 ) at the time of the test. When 
the pressure differs from 101.3 kPa (760 mm Hg), co rrect the flash point or fire point, or both, as fo llows:   
 
 
 
 
 
 
 
where:  
C  = observed flash point, °C,  
F  = observed flash point, °F,  
P  = ambient barometric pressure, mm Hg, and  
K  = ambient barometric pressure, kPa.  
 
NOTE 23—The barometric pressure used in this calculation  is the ambient pressure for the laboratory at the time of test. Many aneroid 
barometers, such as those used at weather stations and airports, are precorrected to give sea level re adings and would not give the correct 
reading for this test.  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     14  
 12.2  Using the corrected flash point or fire point , or both, as determined in 12.1 , round the values to 
the nearest 1 °C (2 °F) and record. 
 
13.  Report  
 
13.1  Report the corrected flash point or fire poin t value, or both, as the Test Method D92 Cleveland 
open cup flash point or fire point, or both, of the  test specimen. 
 
14.  Precision and Bias  
 
14.1  Precision— The precision of this test method as determined by the statistical examination of the 
interlaboratory test results is as follows:  
14.1.1  Repeatability— The difference between successive results, obtained  by the same operator with 
the same apparatus under constant operating conditi ons on identical test material, would in the long r un, 
in the normal and correct operation of the test met hod, exceed the following values in 1 case in 20. 
 
Flash point 8  °C (15  °F) 
Fire point 8  °C (15  °F) 
14.1.2  Reproducibility— The difference between two single and independent r esults, obtained by 
different operators working in different laboratori es on identical material, would in the long run, in  the 
normal and correct operation of the test method, ex ceed the following values only in 1 case in 20. 
 
Flash point 18  °C (32  °F) 
Fire point 14  °C (25  °F) 
14.2  The precision data for fire point is not know n to have been developed in accordance with 
Precision Manual RR:D02-1007. 
NOTE 24—The precisions for fire point were not determine d in the current interlaboratory program. Fire poin t is a parameter that is not 
commonly specified, although in some cases, this te mperature may be desired. 
NOTE 25—The precision for asphalt type samples which hav e had any formed surface film removed has not been determined. 
NOTE 26—The precision for asphalt type samples which hav e utilized the procedure in Appendix X1  have not been determined. 
14.3  Bias— The procedure of this test method has no bias becau se flash point and fire point can be 
defined only in terms of this test method. 
14.4  Relative Bias— Statistical evaluation of the data did not detect a ny significant difference between 
the reproducibility variances of manual and automat ed Cleveland flash point results for the samples 
studied with the exception of multi-viscosity lubri cating oil and white mineral oil. Evaluation of the  data 
did not detect any significant difference between a verages of manual and automated Cleveland flash 
point for the samples studied with the exception of  multi-viscosity lubricating oil, which showed some  
bias. In any case of dispute, the flash point as de termined by the manual procedure shall be considere d 
the referee test. 
14.5  The precision data for flash point were devel oped in a 1991 cooperative test program using seven  
samples of base oils, asphalt, and lubricating oils . Five laboratories participated with the manual 
apparatus and eight laboratories participated with the automated equipment. Information on the type of  
samples and their average flash point are in the re search report available at ASTM Headquarters. 5  
                                                 
5 Supporting data have been filed at ASTM Internatio nal Headquarters and may be obtained by requesting Research Report RR:S15-1009. Contact ASTM 
Customer Service at service@astm.org.  D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    15   
15.  Keywords  
 
15.1  automated Cleveland open cup; Cleveland open cup; fire point open cup for flash point; 
flammability; flash point; petroleum products 
 ANNEXES  
(Mandatory Information)  
A1.  CLEVELAND OPEN CUP TESTER  
A1.1  Test Cup , conforming to Fig. 3  with dimensions as shown with the figure. The cup shall be made 
of brass or other non-rusting metal of equivalent h eat conductivity. The cup may be equipped with a 
handle. 
A1.2  Heating Plate , shall be of sufficient dimension and materials to  ensure that thermal heat to the test 
cup is only applied to the bottom of the test cup a nd that extraneous heat to the test cup other than to the 
bottom is minimized. An example for manual apparatu s that utilize Bunsen burners or exposed electric 
heating elements is shown in Fig. 2 . 
A1.3  Ignition Source Applicator —The device for applying the test flame may be of a ny suitable type. 
When using a test flame, it is suggested that the t ip be 1.6 mm ± 0.05 mm ( 1/16   in.) in diameter at the 
end, and that the orifice be approximately 0.8 mm ±  0.05 mm ( 1/32   in.) in diameter. The device for 
operating the test flame applicator may be mounted in such a manner as to permit automated duplication  
of the sweep of the test flame, the radius of swing  being not less than 150 mm (6  in.). The center of the 
test flame should be supported so that it swings in  a plane not greater than 2 mm ( 5/64   in.) above the 
plane of the rim of the cup. It is desired that a b ead, having a diameter of 3.2 mm to 4.8 mm ( 1/8  in. to 
3/16   in.), be mounted in a convenient position on the apparatus so that the size of the test flame can be  
compared to it. 
NOTE A1.1—A test flame relighting device, such as a pilo t flame, is sometimes used to automatically relight  the test flame in the event 
that it is extinguished during the test. This devic e should be designed such that the unburned gas wil l not spread out over the test cup during 
the relighting. 
A1.4  Heater —Heat may be supplied from any convenient source. T he use of a gas burner or alcohol 
lamp is permitted, but under no circumstances are p roducts of combustion or free flame to be allowed t o 
come up around the cup. An electric heater which ca n be controlled automatically or controlled by the 
user is preferred. The source of heat shall be cent ered under the opening of the heating plate with no  local 
superheating. Flame-type heaters may be protected f rom drafts or excessive radiation by any suitable 
type of shield that does not project above the leve l of the upper surface of the heating plate. 
A1.5  Temperature Measuring Device Support —Any convenient device that will hold the temperatu re 
measuring device in the specified position during a  test and that will permit easy removal of the 
temperature measuring device from the test cup upon  completion of a test may be used. 
A1.6  Heating Plate Support —Any convenient support that will hold the heating plate level and steady 
may be employed. 
A2.  VERIFICATION OF APPARATUS PERFORMANCE  
A2.1  Certified Reference Material (CRM) —CRM is a stable, pure (99  + mole % purity) hydrocarbon or 
other stable petroleum product with a method-specif ic flash point established by a method-specific 
interlaboratory study following RR:D02-1007 6 guidelines or ISO Guide  34 and 35.  
                                                 
6 Supporting data have been filed at ASTM Internatio nal Headquarters and may be obtained by requesting Research Report RR:D02-1007. Contact ASTM  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     16  
 A2.1.1  Typical values of the flash point corrected  for barometric pressure for some reference materia ls 
and their typical limits are given in Table A2.1  (see Note A2.2 ). Suppliers of CRM's will provide 
certificates stating the method-specific flash poin t for each material of the current production batch . 
Calculation of the limits for these other CRM's can  be determined from the reproducibility values of t his 
test method multiplied by 0.7. This value provides a nominal coverage of at least 90  % with 95  % 
confidence. 
 
TABLE A2.1 D92 Typical Flash Point Values and Typic al Limits for CRM  
Hydrocarbon Purity (mole %) Flash Point (°C) Tolera nce 
Limits  
(0.7R)   
(°C) 
n–tetradecane  99  +  115.5 12.5 
n–hexadecane  99  +  138.8 12.5 
NOTE A2.1—Supporting data for the interlaboratory study to generate the flash point in Table A2.1  can be found in research report 
RR:S15-1010. 7  
NOTE A2.2—Materials, purities, flash point values, and l imits stated in Table A2.1  were developed in an ASTM interlaboratory program 
to determine suitability of use for verification fl uids in flash point test methods. Other materials, purities, flash point values, and limits can 
be suitable when produced according to the practice s of RR:D02-1007 or ISO Guides  34 and  35. Certificates of performance of such 
materials should be consulted before use, as the fl ashpoint value will vary dependent on the compositi on of each CRM batch. 
A2.2  Secondary Working Standard (SWS) —SWS is a stable, pure (99  + mole % purity) hydrocarbon, or 
other petroleum product whose composition is known to remain appreciably stable.   
A2.2.1  Establish the mean flash point and the stat istical control limits (3 σ) for the SWS using standard 
statistical techniques. 8  
APPENDIX  
(Nonmandatory Information)  
X1.  TECHNIQUE TO PREVENT SURFACE SKIN FORMATION WH EN TESTING FLASH 
POINT OF ASPHALTS BY TEST METHOD D92  
X1.1   Introduction  
X1.1.1  This technique to prevent surface skin form ation when testing flash point of asphalts by Test 
Method D92 was developed by Imran Hussami of Fronti er El Dorado Refining Company. 
X1.2   Materials Required  
X1.2.1  Filter Paper,  qualitative, No. 417 (or equivalent), 7.5 cm diame ter. 
X1.2.2  Restraining Tension Ring,  metal wire, circular, but with its 15 mm straight ends folded 
inwards, parallel to each other (see Fig. X1.1 ). Dimensions: wire about 2 mm thick, 62 to 63 outs ide 
diameter with bent ends 15 mm apart along the circu mference of the circle. Total length of wire is abo ut 
210 mm. An ordinary metal coat hanger or similar ma terial can be used to make the tension-ring. 
 
                                                                                                                                                                           
Customer Service at service@astm.org. 
7 Supporting data have been filed at ASTM Internatio nal Headquarters and may be obtained by requesting Research Report RR:S15-1010. Contact ASTM 
Customer Service at service@astm.org. 
8 MNL7, Manual on Presentation of Data and Control Chart An alysis , 6th ed., ASTM International, 1990.  D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    17  
 
 
NOTE 1—Use of this alternate technique may cause bubblin g in some samples. Bubbling could interfere with au tomatic flash detection devices, and it also 
may cause a slower heating rate in some samples. 
FIG. X1.1  Technique to Prevent Surface Skin Format ion When Testing Flash Point of Asphalts by 
Test Method D92  
X1.2.3  Single-Hole Punch,  (or equivalent) capable of making a 6 mm diameter hole in the center of 
the filter paper. 
X1.3   Procedure  
X1.3.1  Determine the center of the filter paper by  means of a ruler. Using the single-hole punch, 
punch a 6  mm diameter hole in the center  of the 7.5 cm diameter qualitative filter paper. 
X1.3.2  Curl up the sides of the filter paper, abou t 6 mm all around, and place it in the base of the 
Cleveland open cup flash point test cup, with the 6  mm skirt facing upward (see Fig. X1.1 ). 
X1.3.3  Place the restraining tension-ring snugly o ver the curved portion of the filter paper in the b ase 
of the cup. (The tension-ring prevents the filter p aper from moving upward during the test.) 
X1.3.4  Fill the cup with the sample 4 mm to 5 mm below the filling mark  (this is to compensate for the 
sample that is absorbed by the filter paper which w ill be released during the test). ( Warning— Filling all 
the way to the filling mark could produce premature  flash point results.) 
X1.3.5  Start the test either using a manual tester  or an automatic unit (following manufacturer's 
instructions) and determine the flash point. 
X1.3.6  Report the flash point corrected for bariom etric pressure to the nearest 1 °C.  D92  – 18         FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved     18  
 SUMMARY OF CHANGES 
Subcommittee D02.08 has identified the location of selected changes to this standard since the last 
issue (D92  – 16b) that may impact the use of this standard. (App roved July 1, 2018.) 
(1)   Correction to dimensions and tolerances. 
 
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646-2600; http://www.copyright.com/   D92 – 18  FDUS 2040: 2018  
 
© UNBS 2018  – All rights reserved    19  Certification marking 
Products that conform to Uganda standards may be ma rked with Uganda National Bureau of Standards (UNBS ) 
Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made ther eunder. 
This mark can be used only by those licensed under the certification mark scheme operated by the Ugand a 
National Bureau of Standards and in conjunction wit h the relevant Uganda Standard. The presence of thi s mark on 
a product or in relation to a product is an assuran ce that the goods comply with the requirements of t hat standard 
under a system of supervision, control and testing in accordance with the certification mark scheme of  the Uganda 
National Bureau of Standards. UNBS marked products are continually checked by UNBS for conformity to t hat 
standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda  National 
Bureau of Standards.  
  D92 – 18         FDUS 2040: 2018  
 
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