5.1 This test method, using a slow rate of heating, provides a uniform temperature throughout the specimen. The slow rate of heating is necessary because of the low thermal conductivity of some liquids such as paints, resins, and related products, and also because of the poor heat transfer by convection in high-viscosity products. Since the specimen is being heated at a reduced rate, the longer time interval between each determination is necessary to reestablish after each flash test the saturation concentration of vapor in the air space above the specimen.

Note 1: ISO 1523 is used in United Nations Recommendations for Transportation of Dangerous Goods and in the International Civil Aviation Organization (ICAO) regulations and for similar regulations in the International Maritime Dangerous Goods (IMDG) code. Test Method D3941, which is similar to ISO 1523, is used in the United States Department of Transportation (USDOT) regulations. The ICAO and IMDG codes are used for transshipment of hazardous materials through the United States to other countries.

1.1 This test method covers the determination of the flash point of liquids in which the specimen and the air/vapor mixture above it are approximately in temperature equilibrium.

1.2 This test method is limited to a temperature range from 0 to 110°C (32 to 230°F).

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

1.4 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 used to measure and describe the properties of material, 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, 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.

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 and health practices and determine the applicability of regulatory limitations prior to use.