Milk products purchased between 1985 and 1988 and packaged in plastic-coated bleached paperboard cartons were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Whole and 2% milk samples showed concentrations of 2,3,7, 8-tetrachlorodibenzofuran (2,3,7,8-TCDF) on a whole weight basis of about 1.0 pg/g and, in some cases, of 2,3,7,8-tetrachlorodibenzo-p-dioxin 2,3,7,8-TCDD) about 20-fold less. On a TCDD equivalent (TEQ) basis, cream samples (0.3 pg of TEQ/g) contained about twice as much as whole and 2% fat milk samples, which in turn were about double that of skim milk. A number of bleached paper containers from contaminated food samples analyzed positive for TCDF and TCDD at higher concentrations and in similar proportions. This paper is the first to show a difference in the levels of 2,3,7,8-TCDF and 2,3,7,8-TCDD between milk samples from bleached paperboard containers and those from paper or glass containers. Pharmacokinetic considerations of half-lives and known human adipose tissue levels indicate that the consumption of cows' milk products containing TCDF and TCDD at the above levels could significantly contribute to our body burden of these toxic compounds.