1.1 This guide provides general guidance for developing ASTM unit specification for masonry units manufactured with constituent materials, manufacturing methods, and combinations thereof, that are not included in a current ASTM standard. This guide shall not be construed as permitting the use of a product conflicting with requirements of the governing building code.

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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 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.