In the slag ''Kieselrot'' highly chlorinated, aromatic compounds have been detected as main organic components. Thus pure ''Kieselrot'' contains 1,2,3,4,6,7,8-hepta- and octachlorodibenzofuran, 2,2',3,3',4,4',5,5',6-nona- and decachlorobiphenyl, penta- and hexachlorobenzene, pentachlorophenol as well as hexa- and heptachloronaphthalene in low ppm concentrations. Additionally concentrations of higher than 100 ppm for aluminum, lead, copper and manganese are usually found in this material. The concentrations of polychlorinated dibenzofurans and polychlorinated dibenzodioxins found in pure ''Kieselrot'' are much higher than the limit values specified in the German ''Gefahrstoffverordnung'' (Regulations for Dangerous Substances) and ''Gefahrgutverordnung'' (Regulations for Road Transport of Dangerous Goods). The concentrations of arsenic found in this material exceeds value II of the decree ''Metalle auf Kinderspielplatzen'' (Metals in Childrens' Playgrounds) of Northrhine-Westphalia (NRW). For areas covered with ''Kieselrot'', all TE (Toxicity Equivalent)-values which are currently recommended by the German Federal Health Office/Federal Environment Office (BGA/UBA) are exceeded. The identification of ''Kieselrot'' is possible on the basis of certain parameters from so-called ''screening methods''. The best correlation with the TE-value of relatively pure ''Kieselrot'' was found for decachlorobiphenyl, which is used as test parameter in the NRW-screening test. From the concentration of octachlorodibenzofuran determined at the same time by this method, the PCDF/D homologues and congener concentrations can be calculated relatively accurately, based on the fact, that about the same profile is observed for the PCDF/D in the slag ''Kieselrot''.
