 The life @-@ cycle assessment of bismuth will focus on solders , one of the major uses of bismuth , and the one with the most complete information . The average primary energy use for solders is around 200 MJ per kg , with the high @-@ bismuth solder ( 58 % Bi ) only 20 % of that value , and three low @-@ bismuth solders ( 2 % to 5 % Bi ) running very close to the average . The global warming potential averaged 10 to 14 kg carbon dioxide , with the high @-@ bismuth solder about two @-@ thirds of that and the low @-@ bismuth solders about average . The acidification potential for the solders is around 0 @.@ 9 to 1 @.@ 1 kg sulfur dioxide equivalent , with the high @-@ bismuth solder and one low @-@ bismuth solder only one @-@ tenth of the average and the other low @-@ bismuth solders about average . There is very little life @-@ cycle information on other bismuth alloys or compounds . 
