5.1 Flash point is one of the properties used to define the flammability of a liquid. It is used to classify liquids according to their flammability by governmental regulatory agencies. It may also be used to determine the presence of impurities or contaminants in a given liquid, such as the presence of residual solvents in solvent-refined drying oils. See Test Methods D56 and D93 for alternate flash point testing.

1.1 These test methods cover procedures for determining whether a material does or does not flash at a specified temperature or for determining the lowest finite temperature at which a material does flash when using a small scale closed-cup apparatus.2 The test methods are applicable to paints, enamels, lacquers, varnishes, and related products having a flash point between 0 and 110°C (32 and 230°F) and viscosity lower than 150 St at 25°C (77°F).

Note 1: Tests at higher or lower temperatures are possible.

Note 2: More viscous materials may be tested in accordance with Annex A4.

Note 3: Organic peroxides may be tested in accordance with Annex A5, which describes the applicable safety precautions.

Note 4: The U.S. Department of Labor (OSHA, Hazard Communications), the U.S. Department of Transportation (RSPA), and the U.S. Environmental Protection Agency (EPA) have specified Test Methods D3278 as one of several acceptable methods for the determination of flash point of liquids in their regulations.

Note 5: These test methods are similar to International Standards ISO 3679 and ISO 3680.

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

1.3 This standard should be used to measure and describe the response of materials, products, or assemblies to heat and flame under controlled conditions and should not be used to describe or appraise the fire-hazard or fire-risk of materials, products, or assemblies under actual fire conditions. However, results of the test may be used as elements of a fire-hazard or a fire-risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard or fire risk of a particular end use.

1.4 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 hazard statements, see 8.1 and 11.2.

1.5 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.