The flash point temperature 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 which must be considered in assessing the overall flammability hazard of a material.

Flash point is used in shipping and safety regulations to define flammable and combustible materials and for classification purposes. This definition may vary from regulation to regulation. Consult the particular regulation involved for precise definitions of these classifications.

This test method can be used to measure and describe the properties of materials in response to heat and an ignition source under controlled laboratory conditions and shall not be used to describe or appraise the fire hazard or fire risk of materials under actual fire conditions. However, results of this test method 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.

Flash point can also indicate the possible presence of highly volatile and flammable materials in a relatively nonvolatile or nonflammable material, such as the contamination of lubricating oils by small amounts of diesel fuel or gasoline. This test method was designed to be more sensitive to potential contamination than Test Method D6450.

1.1 This test method covers the determination of the flash point of fuels, lube oils, solvents and other liquids by a continuously closed cup tester utilizing a specimen size of 2 mL, cup size of 7 mL, with a heating rate of 2.5°C per minute.

1.1.1 Apparatus requiring a specimen size of 1 mL, cup size of 4 mL, and a heating rate of 5.5°C per minute must be run according to Test Method D6450.

1.2 This flash point test method is a dynamic method and depends on definite rates of temperature increase. It is one of the many flash point test methods available and every flash point test method, including this one, is an empirical method.

Note 1—Flash point values are not a constant physical chemical property of materials tested. They are a function of the apparatus design, the condition of the apparatus used, and the operational procedure carried out. Flash point can, therefore, only be defined in terms of a standard test method and no general valid correlation can be guaranteed between results obtained by different test methods or where different test apparatus is specified.

1.3 This test method utilizes a closed but unsealed cup with air injected into the test chamber.

1.4 This test method is suitable for testing samples with a flash point from 35 to 225°C.

Note 2—Flash point determinations below 35°C and above 225°C may be performed; however, the precision has not been determined below and above these temperatures.

1.5 If the user’s specification requires a defined flash point method other than this method, neither this method nor any other test method should be substituted for the prescribed test method without obtaining comparative data and an agreement from the specifier.

1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6.1 Temperatures are in degrees Celsius, pressure in kilo-Pascals.

1.7 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 and health practices and determine the applicability of regulatory limitations prior to use. For specific warning statements, see 7.2, 8.5, and 10.1.2.