ASTM D3934-20

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D3934 − 14 D3934 − 20
Standard Test Method for
Flash/No Flash Test—Equilibrium Method by a Closed-Cup
Apparatus
This standard is issued under the fixed designation D3934; 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.
INTRODUCTION
ASTM Flash Point Test Methods D56, D93, D3278, and D3941 are specified by government
departments and agencies for determining whether liquids are flammable or combustible. These
classifications are used as the basis for regulating the handling and shipping of liquids.
ISO/TC 35, Paints and Varnishes, and ISO/TC 28, Petroleum and Related Products, have issued ISO
1516 as a common standard, applicable to paints, varnishes, petroleum, and related products. This
method is similar to ISO 1516 but uses standard ASTM cups and style and format. Test Methods
D3278 and D3828 operate on the equilibrium principle by using the Setaflash tester that has a
temperature-control device.
This test method does not determine the finite flash point but whether or not flashing occurs at a
single specified temperature. The latter determination is made more accurate by ensuring that the test
is carried out only when the material under test and the air/vapor mixture above it are in approximate
equilibrium at the specified temperature.
1. Scope*Scope
1.1 This test method covers the determination of whether a liquid complies with the closed-cup flash point requirements in
government regulations, or in specifications, or as agreed between the purchaser and the seller.
1.2 This test method is limited to a temperature range between 0 and 110°C (32 and 230°F).
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.4 Warning—Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious
medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use caution
when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional
information. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or national
law. Users must determine legality of sales in their location.Warning—Mercury has been designated by many regulatory agencies
as a hazardous material that can cause central nervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous
to health and corrosive to materials. Caution should be taken when handling mercury and mercury containing products. See the
applicable product Safety Data Sheet (SDS) for details and EPA’s website, http://www.epa.gov/mercury/faq.htm, for additional
information. Users should be aware that selling mercury and/or mercury containing products into your state or country may be
prohibited by law.
1.5 This standard should be is used to measure and describe the propertiesresponse of materials, products, or assemblies in
response to heat and flame under controlled laboratory conditions and should not be used to describe or appraise theconditions,
but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies
under actual fire conditions. However, results of this test 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.
This test method is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility of ASTM
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
Current edition approved Dec. 15, 2014June 1, 2020. Published January 2015June 2020. Originally approved in 1982. Last previous edition approved in 20072014 as
D3934 – 90 (2007).D3934 – 14. DOI: 10.1520/D3934-14.10.1520/D3934-20.
*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
D3934 − 20
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.7 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:
D56 Test Method for Flash Point by Tag Closed Cup Tester
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D3278 Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus (Withdrawn 2020)
D3828 Test Methods for Flash Point by Small Scale Closed Cup Tester
D3941 Test Method for Flash Point by the Equilibrium Method With a Closed-Cup Apparatus
E1 Specification for ASTM Liquid-in-Glass Thermometers
E1137 Specification for Industrial Platinum Resistance Thermometers
E2251 Specification for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision Liquids
E2877 Guide for Digital Contact Thermometers
2.2 ISO Standard:
ISO 1516 Paints, varnishes, petroleum, and related products—Flash/no-flash test—Closed cup equilibrium method
3. Terminology
3.1 Definitions:
3.1.1 flash point, n—the lowest temperature corrected to a pressure of 760 mm Hg (101.3 kPa) (1013 millibars) at which
application of an ignition source causes the vapor of the specimen to ignite under specified conditions of test.
4. Summary of Test Method
4.1 A specimen in a closed cup of standard design is heated in a suitable liquid bath. After the specimen has been maintained
under equilibrium conditions for at least 10 min at the lowest allowable flash point temperature (within a permitted tolerance) of
the specification or regulation, it is determined whether the specimen does or does not flash.
5. Significance and Use
5.1 This test method ensures that before the flash test is run the air/vapor space above the specimen has attained a saturation
concentration of vapor by using standard closed cups under equilibrium conditions. The saturation concentration of the vapors will
be attained at some temperature between that of the liquid and the cooler apparatus lid. However, this temperature will be close
to the temperature of the specimen after it has been maintained at the specified temperature for at least a 10-min period. This test
method does not provide for the determination of the actual flash point but only whether a specimen does or does not flash at a
specified temperature.
6. Apparatus
6.1 Test Cups, specified in Test Methods D56 (Tag) and D93 (Pensky-Martens). Remove the test cup assembly (including lid
and specimen thermometer) from the Tag and Pensky-Martens apparatus to permit either to be used in a separate water bath.
NOTE 1—If a stirrer is fitted to the test cup, it shall be operated during the heating period but must be stopped during the flashing determination. If
a stirrer originally fitted to the test cup is removed, the aperture in the cover shall be securely plugged before starting the test.
6.2 Liquid Bath, capable of being adjusted to the required specification temperature and of adequate heat capacity to meet the
requirements of the test. A bath fitted with a stirrer and an adjustable thermostat is convenient (see 9.2).
NOTE 2—The bath should be fitted with a cover, especially when the specified temperature is above 160°F. At about this temperature the inerting effect
of the water vapor may prevent or delay the flashing of the liquid under test.
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