DBTC Estimate of Exposure. Estimates of exposure for DBTC were generated by modeling the migration of dibutyltin from plastic food packing into foods based on physicochemical parameters and initial amounts of the chemical in the packaging. Human exposure to foods containing dibutyltin was estimated using food diaries from NHANES. The 1st, 25th, 50th, 75th, and 99th percentiles of exposure were calculated for the total population and for various subgroups. Estimates were computed and plotted separately when considering different uses for DBTC as A) a catalyst or B) a heat stabilizer. C) Exposure values for the total population were plotted for use of DBTC as a catalyst, heat stabilizer, or combined use.