Used primarily in organic synthesis as a reagent for introducing iodine atoms into molecules. It is also employed in the preparation of iodinated compounds, which are valuable intermediates in pharmaceuticals and agrochemicals. In analytical chemistry, it serves as a heavy liquid for density separations. Additionally, it finds application in the study of radical reactions due to its ability to generate iodine radicals under certain conditions. Its use is limited in industrial applications due to toxicity and environmental concerns.