Tincture of iodine, iodine tincture, or weak iodine solution is an antiseptic. It is usually 2% elemental iodine, along with potassium iodide or sodium iodide, dissolved in a mixture of ethanol and water. Tincture solutions are characterized by the presence of alcohol. It was used from at least 1907 in emergency pre-operative skin preparation by the Italian surgeon Antonio Grossich; three years later, an experimental study at the University of Genoa’s Institute of Hygiene resulted in a mere 3% infection rate in injuries treated by Grossich’s disinfection method, as against 21% in those treated by the prevailing method.