Sodium Dithionite, Rongalite and Thiurea Oxides provides an in depth overview of historical and newly developed fields of application for important sulfur-containing reductants. It begins with an introduction into the structure and general properties of sodium dithionite, sodium hydroxymethanesulfinate (rongalite) and thiourea oxides. Following this there is analysis of their stability in different types of solutions, and reactions with both organic and inorganic compounds. Finally, there is description of the application of the reductants in industry, using examples of the textile, printing and paper industries, as well as in polymerization processes.Despite widespread practical application, the mechanism behind these compounds is not fully understood, due to their unusual structure and complex decomposition within solutions. This comprehensive review presents up-to-date findings to both academics and industrial chemists, aiming to increase knowledge and provide both fundamental and technical data dedicated to these relatively simple chemicals which have wide practical applications.