4.1 This test method measures the tendency for oil components to separate spontaneously from asphalt. The separation of oil components can cause staining in asphalt roofing products and adjacent materials in storage and use.

4.2 The stain index is related to the thermal stability of the asphalt. Higher stain index values indicate lower stability and greater tendency for staining.

4.3 Use this procedure to determine the staining tendency of asphalt and to compare the results against a material for which the staining tendency is known.

1.1 This test method covers the determination of the staining tendency of asphalt and the assignment of a stain index proportional to the extent of staining observed.

1.2 This test method is applicable to asphalts having ring-and-ball softening points of 85 °C [185 °F] or greater.

Note 1: This test method may be modified for use with other bituminous materials with softening points less than 85 °C [185 °F] by using a different temperature than specified in Section 7 by agreement of the interested parties. The report of results from such a test may cite this method but must clearly state the temperature employed in the exception and acknowledge that the interpretation of results in Section 9 and the precision and bias stated in Section 10 may not apply.

1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

1.4 This standard does not purport to address 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.

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.