M11 PM Internal Exposure
Monday, 14 November 2005: 1:50 PM - 5:30 PM in 343-344

(SAL-1117-814036) A scheme for using internal exposure in environmental risk assessment: The ECETOC Task Force on Risk Assessment of PBTs and vPvBs.

Salvito, Daniel¹, Thomas, Paul², Malcomber, Ian³, Tolls, Johannes⁴, Holt, Martin⁵, ¹ RIFM, Woodcliff Lake, NJ, USA² Akzo-Nobel Chemicals, Arnhem, The Netherlands³ Unilever, Bedfordshire, United Kingdom⁴ Henkel, Dusseldorf, Germany⁵ ECETOC, Brussels, Belgium

ABSTRACT- As presented at the SETAC European meeting in Lille (2005), ECETOC has established a task force to identify the technical and methodological feasibility of risk assessing PBT and vPvB type chemicals in anticipation of REACH under the pending EU Chemicals Policy. As part of this task force's recommendations for higher tier risk assessments, a scheme was developed to refine and replace the Predicted No Effect Concentration of these chemicals with estimates and measurements of lethal and chronic critical body burdens (CBB). The Task Force believes that this methodology would be applicable to chemicals with mode of action (MOA) I and II (non-polar and polar narcotics) and possibly MOA III (reactive chemicals). However, MOA IV chemicals (unique modes of action) would need to be evaluated on a case-by-case basis. At the lowest tier of this effects assessment, Lethal Body Burdens can be estimated by QSARs or measured from acute toxicity studies. Higher tiers within the effects assessment would estimate chronic CBBs from chronic toxicity studies and bioaccumulation measurements, and ultimately measure body burdens from full life cycle studies. These CBBs would be compared to exposure based body burden residues, either modeled or measured, at various trophic levels to determine if an environmental risk is present.

Key words: critical body burden, risk assessment, PBT and vPvB chemicals, REACH