In this preliminary study, the accessibility of Hexachlorobenzene (HCB) and Hexachlorobuta-1,3-dien (HCBD) was determined for a grassland soil sample from Carinthia. Using a contaminant trap with an adsorption sink, only low desorption resistant fractions were observed for HCB (7%) and HCBD (22%). A similar low desorption resistant fraction was found for arable soil spiked with HCB. In contrast, a significant higher retention of HCB was measured for soil rich in carbonaceous organic matter. This preliminary study reveals that a fraction of HCB as present in common grassland and arable soils may be accessible and as a consequence enter the food chain. However, the retention of HCB in soils can be increased by the addition of carbonaceous sorbents such as biochar eventually resulting in a decrease of HCB uptake in biota.