Tin allowed for the much more complex shapes cast in closed moulds of the Bronze Age. Arsenical bronze objects appear first in the Near East where arsenic is commonly found in association with copper ore, but the health risks were quickly realized and the quest for sources of the much less hazardous tin ores began early in the Bronze Age. This created the demand for rare tin metal and formed a trade network that linked the distant sources of tin to the markets of Bronze Age cultures. Cassiterite (SnO), the tin oxide form of tin, was most likely the original source
Antimicrobial copper-alloy touch surfaces Copper (Cu) is a logo/mark required by the U.S. E.P.A. in order for bulk metal fabricators and manufacturing companies to make public health claims about antimicrobial copper in the U.S. market. The logo/mark indicates that the products have strong efficacies as sanitizers, residual self-sanitizing efficacies after multiple wet-dry cycles, and continuous reductions of bacterial contaminants. A list of bulk alloy suppliers that offer E.P.A.-registered antimicrobial copper to manufacturers is available. A list of approved manufacturers and retailers offering antimicrobial copper products to the regulated U.S. market is also available. These firms have completed all legal requirements to sell antimicrobial copper