Prehistoric technology Ground and polished stone tools continued to be created and used during the Neolithic period. Numeric record keeping evolved from a system of counting using small clay tokens that began in Sumer about 8000 BC. The Stone Age developed into the Bronze Age after the Neolithic Revolution. The Neolithic Revolution involved radical changes in agricultural technology which included development of agriculture, animal domestication, and the adoption of permanent settlements. The Bronze Age is characterised by metal smelting of copper and its alloy bronze, an alloy of tin and copper, to create implements and weapons. Polished stone tools continued to be
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