Solar-cell manufacture is a precise, exacting process that can tolerate no inefficiencies or errors in production. While precise, though, the manufacture of solar cells is also a very harsh process. After solar cells are cut into wafers they must be cleaned and polished, resulting in hard and sharp waste pieces of silicon particles that must be disposed of. In addition, some of the liquids used to polish the solar-cell wafers are quite abrasive and after their use they are usually cleaned of any impurities, filtered and re-used.