Tetrachlorodibenzo-p-dioxin in baby food made from chicken produced before and after the termination of ball clay use in chicken feed in the United States

Polychlorodibenzo-p-dioxin/furans were determined in chicken-containing baby foods collected from an annually conducted total diet survey by the US FDA during the last half of fiscal year (FY) 1997 through the first half of FY 1998. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) was found in 8 of 11 baby food samples. The levels were between 0.025 and 0.28 ng kg−1 wet wt (0.25-5 ng kg−1 lipid). The mean TCDD value for chicken-containing baby food with “nondetects” equal to 0 was 1.2 ng kg−1 lipid, eight times higher than the average level found during a previous survey of chicken lipid TCDD levels in 1996. All other 2,3,7,8-chlorine-substituted dibenzo-p-dioxin congeners were also found with a profile consistent with the use of ball clay in chicken feed. TCDD was not detected in any FY 2000 baby foods made with chicken, with an average limit of detection (LOD) of 0.025 ng kg−1 wet wt. Whole eggs collected in 1997 from producers that never used ball clay in feed revealed TCDD measurements that were nearly all nondetects and none above the median LOD of 0.015 ng kg−1 wet wt. The percentage of chickens fed ball clay in their feed was estimated to be between 2.6% and 3.5% of all chickens produced in the United States in 1997.