1.1 This classification covers commercial fusion-cast refractory blocks and shapes. Its purpose is to set forth the various types and classes of these materials according to their mineralogical compositions. These compositions are important to determining their suitability for use in specified applications. This standard is not intended to cover commercial fused grains or beads.

1.2 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 requirements prior to use.