4.1 The toluene discoloration value provides an estimate of toluene-soluble discoloring residues present on the carbon black.

1.1 This test method covers the measurement of the degree of toluene discoloration by carbon black extractables and is useful in controlling the reaction processes for production of carbon black. This test method may not be applicable to carbon blacks with high extractables.

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

1.3 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.

1.4 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.