The Flemish Environment Agency (VMM) measures PCDD/Fs, shortly dioxins, and dioxin-like PCBs (DL-PCBs) in deposition to investigate whether these substances are precipitating from the air and whether there is a potential risk of uptake via the food chain. There is currently no Flemish regulation on dioxins and DL-PCBs in deposition. However, the VMM had derived threshold values in 2007 for the sum of 17 dioxins and 12 DL-PCBs in deposition [1]. The current annual average threshold is 8.2 pg TEQWHO1998/(m².day) and was derived using the Tolerable Weekly Intake (TWI) of 14 pg TEQWHO1998/kg bw/week for the group of PCDD/Fs and DL-PCBs proposed by the EU SCF [2]. EFSA revised the TWI for PCDD/Fs and DL-PCBs in 2018. They lowered the TWI to 2 pg TEQWHO2005/kg bw/week [3], which requires a revision of the current Flemish thresholds. This requires the identification of a suitable transfer and exposure model that allows source-to-dose calculations. In addition, a method should be developed to derive threshold values ...