Regulation (EU) 2019/1021 on persistent organic pollutants (POP:s-regulation) amended through regulation (EU) 2022/2400, stipulates that the member states are requested to collect data on the levels of dioxins (PCDD/Fs) and PCBs from biomass combustion units. In the present report, results from a screening study on PCDD/Fs and PCBs in ash and soot from Swedish household small-scale biomass combustion units, are presented. An assessment of toxic equivalents (TEQs) in bottom ash and fly ash from biomass heat and power plants was performed based on existing data. The result shows low levels TEQs, below 0.5 μg TEQ WHO2005/kg in bottom ash and fly ash from larger biomass combustion units, as well as low levels of in wood ash from small-scale units. Soot samples from household small-scale biomass combustion show more variable concentrations with the highest TEQ-levels detected in the range 1-2 μg TEQ/kg soot. The data is in line with results reported from other EU states. The investigated small-scale units were typical and representative for Swedish conditions. Thus, the monitored TEQs from the present study is deemed to be representative for ash and soot from small-scale wood heating units in Sweden. The results indicate that ash and soot should not be classified as POPs-waste since TEQ-levels are significantly lower than the limit value of 5 μg TEQ WHO2005/kg set out in annex IV to the POP:s regulation.
