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 toxicity the interaction of fruit acid with copper, permitting the use of the metal for its efficient thermal transfer properties. OSHA has set safety standards for grinding and sharpening copper and copper alloy tools, which are often used in nonsparking applications. These standards are recorded in the Code of Federal Regulations 29 CFR 1910.134 and 1910.1000. Note: The most important nonsparking copper alloy is beryllium copper, and can lead to beryllium poisoning. With an of 30 mg/kg in rats, "gram quantities" of copper sulfate are potentially lethal in humans. The suggested safe level of copper in drinking water for humans varies