Tin be toxic. Tin in combination with other elements forms a wide variety of useful alloys. Tin is most commonly alloyed with copper. Pewter is 85–99% tin; bearing metal has a high percentage of tin as well. Bronze is mostly copper (12% tin), while addition of phosphorus gives phosphor bronze. Bell metal is also a copper–tin alloy, containing 22% tin. Tin has sometimes been used in coinage; for example, it once formed a single-digit percentage (usually five percent or less) of American and Canadian pennies. Because copper is often the major metal in such coins, sometimes including zinc, these could be
Copper alloys in aquaculture other microbes. (For information about the antimicrobial properties of copper and its alloys, see Antimicrobial properties of copper and Antimicrobial copper alloy touch surfaces). In the marine environment, the antimicrobial/algaecidal properties of copper alloys prevent biofouling, which can briefly be described as the undesirable accumulation, adhesion, and growth of microorganisms, plants, algae, tube worms, barnacles, mollusks, and other organisms on man-made marine structures. By inhibiting microbial growth, copper alloy aquaculture pens avoid the need for costly net changes that are necessary with other materials. The resistance of organism growth on copper alloy nets also provides a cleaner and healthier environment