Antimicrobial copper-alloy touch surfaces follows: The following claims are now legally permitted when marketing EPA-registered antimicrobial copper alloys in the U.S.: The registrations state that “antimicrobial copper alloys may be used in hospitals, other healthcare facilities, and various public, commercial and residential buildings.” The EPA copper alloy registrations were granted “with public health claims,” meaning that they permit manufacturers of copper-based products sold in the U.S. to claim on their labels the ability of copper, brass, and bronze to kill harmful, potentially deadly bacteria. As a condition of registration established by EPA, the Copper Development Association (CDA) in the U.S. is responsible for the
Chinese sun and moon mirrors most (1 part tin per 1 part copper) for "metallic mirrors", namely, the "jiànsuì" 鑒燧 "mirror-igniter" alloy (Hirth 1907: 217-218). However, these ratios are based on Chinese numerology instead of practical metallurgy. Beyond about 32% the alloy becomes excessively brittle, and increasing tin content brings no further advantages of any kind; this the Han metallurgists evidently knew. Indeed they knew much more, for they almost always added up to 9% of lead, a constituent which greatly improved the casting properties. Han specular metal is truly white, reflects without tinning or silvering, resists scratching and corrosion well, and was admirably adapted