1. Scope 1.1 This test method covers determining the activity of equilibrium or laboratory-deactivated fluid catalytic cracking (FCC) catalysts, or both. This is evaluated on the basis of weight percent conversion of gas oil in a microactivity unit. The selectivity of FCC catalysts can be determined using Test Method D5154. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only. 1.3 This standard does not purport to address all of the safety problems, 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.