The properties that are included on Certificate of Analysis data sheets can fall short of meeting the needs of smelters and downstream customers when there is not a strong understanding of what is required along the value stream. Some requirements are direct. The content of ZnO in SGA can be almost directly translated into metal customer specifications. Other requirements are not so direct such as with conductivity of transmission cable. The combined content of SiO2, Fe2O3, Cr2O3, MnO, ZrO2, TiO2 and V2O5 may rule out some SGA sources at certain smelters that are acceptable at others. The author presents observations upon these and other properties of SGA and what they imply with regard to downstream customer requirements.