Document Dd8yL6Dgpg6awzz41edy01gX4

TO G. Roush, Jr. As you veil know, two things will be necessary to set specifications for limits of dioxins in products. The first is an analytical method capable of detecting dioxins at very low (ppb) limits. Following that, it will be necessary to determine the specific levels of dioxins in the product, and to develop procedures for ensuring that they are not exceeded. The other requirement is that we have some biological indicator to estimate the "safety factor" that will be provided if the specification is observed. I suggest that we perform (1) a rabbit ear chloracne test and (2) a chick edema bioassay on the specific dioxins involved. These two tests are of relatively short duration and they give a decided response to dioxins. We should be able to determine levels at which these effects are not produced, and we could compare those "no-effect" levels against the product levels of dioxins to estimate a "safety factor". Needless to say, we will need specific dioxin isomers for these biological tests. . IN 1CM ' R E V 2 / ; 3 l 236Ste