Copper in architecture used in residential and commercial building structures. Variations in color stem primarily from differences in the alloy chemical composition. Some of the more popular copper alloys and their associated Unified Numbering System (UNS) numbers developed by ASTM and SAE are as follows: In practice, the term ‘bronze’ may be used for a variety of copper alloys with little or no tin if they resemble true bronzes in color. Further information on architectural copper alloys is available. The criteria by which copper and copper alloys are selected for architectural projects include color, strength, hardness, resistance to fatigue and corrosion, electrical and
Antimicrobial copper-alloy touch surfaces in April 2011 analyzed the effectiveness of copper-alloy furnishings to lessen the microbial load on various frequently touched surfaces such as door handles, toilet seats, and railings. Of the 14 surfaces tested 8 had statistically significant decreases in the number of microbes found on them while the other 6 had a decrease in the number of microbes as well, but not in a statistically significant amount. Additionally certain microbes in particular were found in far less quantities on the copper-alloy surfaces than on the normal ones, these being Vancomycin-resistant "Enterococcus", "Staphylococcus aureus", and Coliform bacteria. The study concluded that copper