5.1 The flash point measures the response of the sample to heat and flame under controlled laboratory conditions. It is only one of a number of properties that must be considered in assessing the overall flammability hazard of a material.

5.2 As a result of physical factors inherent in the apparatus and procedure, the closed cup flash point does not necessarily represent the minimum temperature at which a material can evolve flammable vapors, and the absence of a flash point does not guarantee nonflammability (see Appendix X1 and Appendix X2).

5.3 Flash point is used in shipping and safety regulations to define flammable and combustible materials. Test Methods D56, D93, and D3278 are specified as test methods for determining the flash point of these materials.

5.4 If the process or handling conditions dictate the usage of a flammable material at temperatures ranging upward from 5 to 10°C below the closed-cup flash point, then a flammable vapor might be present above the liquid. In such cases, it may be more appropriate to use the temperature limit of flammability (as determined by Test Method E1232) instead of flash point.

5.5 For single component samples, small-scale methods involving equilibrium procedures and only one flame pass per specimen are preferred.

5.6 For mixtures containing small concentrations of volatile components, special procedures are needed to minimize the loss of volatiles, with consequent elevation of the flash point, while the sample is being heated. (See X2.5.)

5.7 In cases where errors caused by loss of volatiles, downwards flame direction and quenching are unacceptable, the “lower temperature limit of flammability” can be determined instead using Test Method E1232. The temperature limit of flammability test chamber is sufficiently large to overcome flame quenching effects in most cases of practical importance, thus, usually indicating the presence of vapor-phase flammability if it does exist.

1.1 This test method covers the determination of the flash point of liquid and solid chemical compounds flashing from below −10 to 370°C (16 to 700°F). The procedures and apparatus in Test Methods D56, D93, D3278, D3828, and D3941 are to be used. Modification to these procedures are specified for tests on solids and viscous liquids. The significance of the results obtained is discussed along with possible sources of error and factors that might cause interference.

1.2 Suggestions for adapting this procedure to mixtures of chemicals are included (see Appendix X2).

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

1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.5 Warning—Mercury has been designated by the United States Environmental Protection Agency (EPA) and many state 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 Material Safety Data Sheet (MSDS) for details and EPA’s website — http://www.epa.gov/mercury/faq.htm — for additional information. Users should be aware that selling mercury or mercury-containing products, or both, into your state may be prohibited by state law.

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. See also Section 8.

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.