 Bismuth compounds account for about half the production of bismuth . They are used in cosmetics , pigments , and a few pharmaceuticals , notably bismuth subsalicylate , used to treat diarrhea . Bismuth 's unusual propensity to expand upon freezing is responsible for some of its uses , such as in casting of printing type . Bismuth has unusually low toxicity for a heavy metal . As the toxicity of lead has become more apparent in recent years , there is an increasing use of bismuth alloys ( presently about a third of bismuth production ) as a replacement for lead . 
