1.1 These test methods describe techniques to evaluate three types of staining or discoloration that rubber may cause when in contact with or in proximity to another surface that may be light colored. 1.2 The test methods also describe how to qualitatively evaluate the degree of staining or discoloration produced in such situations. 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 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.