To exclude material impacts, as far as possible several PCDD/F balancing experiments were performed in the bypass of a waste incineration plant using a glass made wet scrubbing system. Within the limits of measurement accuracy, closed PCDD/F balances were obtained. Hence, new PCDD/F formation during scrubbing can be excluded. Shiftings of the homologue profiles by dechlorination reactions were not observed. (C)1998 Elsevier Science Ltd. All rights reserved