THRESHOLD OF TOXICOLOGICAL CONCERN (TTC) IN RISK ASSESSMENT Prof. Dr. Robert Kroes Institute for Risk Assessment Sciences (IRAS) Utrecht University The Netherlands Tox. Forum 20 0ctober 2004 1 Acknowledgement Tox. Forum 20 0ctober 2004 2 What this lecture is NOT about 100 90 80 70 % Response 60 50 40 30 20 10 0 0.01 0.1 1 10 100 Control incidence Dose (mg/kg/day) Threshold intake below w