Under conditions simulating the gastrointestinal tract, C102, HOC1, and NH2C1 caused covalent organification of iodide to nutrient biochemicals. The extent of binding seemed to be proportional to the EMF and stoichiometry of the redox couple between iodide and the oxidant. Almost half of seventy-one nutrients examined were found to bind reactive iodine. Iodide was found to inhibit the quinoidal chromogen formation from tyrosine and C102, demonstrating the preferential generation of reactive iodine in complex organic mixtures. These findings indicate that ingestion of residual disinfectants via drinking water may pose a health risk in terms of in vivo generation of iodinated organics. Structure, formation, and biological activity of these compounds are under study.