If you are an ASTM Compass Subscriber and this document is part of your subscription, you can access it for free at ASTM Compass
    ASTM D56 - 21

    Standard Test Method for Flash Point by Tag Closed Cup Tester

    Active Standard ASTM D56 | Developed by Subcommittee: D02.08

    Book of Standards Volume: 05.01


      Format Pages Price  
    PDF 13 $58.00   ADD TO CART
    Hardcopy (shipping and handling) 13 $58.00   ADD TO CART
    Standard + Redline PDF Bundle 26 $69.00   ADD TO CART
    Online TrainingTraining  



    Significance and Use

    5.1 Flash point measures the tendency of the specimen to form a flammable mixture with air under controlled laboratory conditions. It is only one of a number of properties that shall 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. One should consult the particular regulation involved for precise definitions of these classes.

    5.3 Flash point can indicate the possible presence of highly volatile and flammable materials in a relatively nonvolatile or nonflammable material. For example, an abnormally low flash point on a sample of kerosene can indicate gasoline contamination.

    1. Scope

    1.1 This test method covers the determination of the flash point, by Tag manual and automated closed testers, of liquids with a viscosity below 5.5 mm2/s (cSt) at 40 °C (104 °F), or below 9.5 mm2/s (cSt) at 25 °C (77 °F), and a flash point below 93 °C (200 °F).

    1.1.1 Two sets of test conditions are used within this test method: low temperature (LT) test conditions for expected flash points < 60 °C, and high temperature (HT) test conditions for expected flash points of  60 °C.

    1.1.2 For the closed-cup flash point of liquids with the following properties: a viscosity of 5.5 mm2/s (cSt) or more at 40 °C (104 °F); a viscosity of 9.5 mm2/s (cSt) or more at 25 °C (77 °F); a flash point of 93 °C (200 °F) or higher; a tendency to form a surface film under test conditions; or containing suspended solids, Test Method D93 can be used.

    1.1.3 For cut-back asphalts refer to Test Methods D1310 and D3143.

    Note 1: The U.S. Department of Transportation (RSTA)2 and U.S. Department of Labor (OSHA) have established that liquids with a flash point under 37.8 °C (100 °F) are flammable as determined by this test method for those liquids that have a viscosity less than 5.5 mm2/s (cSt) at 40 °C (104 °F) or 9.5 mm2/s (cSt) or less at 25 °C (77 °F), or do not contain suspended solids or do not have a tendency to form a surface film while under test. Other flash point classifications have been established by these departments for liquids using this test method.

    1.2 This test method can be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and cannot be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test method can be used as elements of fire risk assessment that takes into account all of the factors that are pertinent to an assessment of the fire hazard of a particular end use.

    1.3 Related standards are Test Methods D93, D1310, D3828, D3278, and D3941.

    1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

    1.5 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.

    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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific warning statements see 6.5, 7.1, 9.3, 11.1.4, and refer to Safety Data Sheets.

    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 (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

    Federal Test Method Standards

    Method1101, Federal Test Method Standard No. 791b

    Method4291, Federal Test Method Standard No. 141A

    ASTM Standards

    D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester

    D1310 Test Method for Flash Point and Fire Point of Liquids by Tag Open-Cup Apparatus

    D3143 Test Method for Flash Point of Cutback Asphalt with Tag Open-Cup Apparatus

    D3278 Test Methods for Flash Point of Liquids by Small Scale Closed-Cup Apparatus

    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

    D4057 Practice for Manual Sampling of Petroleum and Petroleum Products

    D6299 Practice for Applying Statistical Quality Assurance and Control Charting Techniques to Evaluate Analytical Measurement System Performance

    D6300 Practice for Determination of Precision and Bias Data for Use in Test Methods for Petroleum Products, Liquid Fuels, and Lubricants

    E1 Specification for ASTMLiquid-in-Glass Thermometers

    E502 Test Method for Selection and Use of ASTM Standards for the Determination of Flash Point of Chemicals by Closed Cup Methods

    ISO Standards

    ISO 17034


    ICS Code

    ICS Number Code 75.080 (Petroleum products in general); 87.040 (Paints and varnishes)

    Referencing This Standard
    Link Here
    Link to Active (This link will always route to the current Active version of the standard.)

    DOI: 10.1520/D0056-21

    Citation Format

    ASTM D56-21, Standard Test Method for Flash Point by Tag Closed Cup Tester, ASTM International, West Conshohocken, PA, 2021, www.astm.org

    Back to Top