ASSESSMENT OF THE EROD INDUCING POTENCY OF 11 2,3,7,8-SUBSTITUTED PCDD/FS AND 3 COPLANAR PCBS IN THE CHICK-EMBRYO

A bioassay for future use for dioxin risk assessment is presented. Dose effect relationships are set up for 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD, 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 1,2,3,7,8,9-HxCDD, 1,2,3,4,6,7,8-HpCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDF, 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 1,2,3,6,7,8-HxCDF, 3,3',4,4'-TCB, 3,3',4,4',5-PeCB and 3,3',4,4',5,5'-HxCB in the chick embryo. Relative EROD inducing potencies are compared to. TEFs used for human risk assessment. Total potency of a test sample is estimated 26% higher with the chick embryo TEFs than with the International accepted TEFs for human risk assessment.