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Show Page 3 Tables 2A and 2B: Both of these tables list the data obtai ned from tests of 10 different incinerators on: • The distribution of 2,3,7,8- substituted isomers in each of the five 04-8 homologues as a percentage of the total 04-S. • The distribution of 2,3,7,8- substituted isomers in each of the f i ve F4-8 homologues as a percentage of the total F4-S. Both tables also provide the overall average percentage distribution of 2,3,7,8-substituted isomers in each of homologues. It is generally agreed that the 2,3,7,8- substituted isomers arc more toxic than the other isomers, and it is also generally agreed that the most toxic isomer is the 2,3, 7, 8-tetrachlorinated dioxin (2,3, 7, 8--D4 ) . Many methods have been proposed for estimating the overall toxicity of the total dioxin and furan emissions in terms of an equivalent amount of 2,3,7,8-04. Table 2A uses the toxic equivalent factors proposed by Eadon et al (1982), and Table 2B uses the factors proposed by the California Oepartment of Health Services (1986). Application of those two sets of factors to the 2,3,7,8-substituted isomer distributions in Tables 2A and 28 results in these two estimates of the overall average toxicity of dioxin and furan emissions from refuse incinerators: Table 2A, using the factors proposed by Badon et al: 1 unit of 04 -S emissions is equivalent to 0.02503 units of 2,3,7,8- D4 1 unit of F4-S emissions is equivalent to 0.02761 units of 2, 3, 7 , 8--04 Table 2B, using the factors proposed by the California DOHS: 1 unit of 04-8 emissions is equivalent to 0.02806 units of 2,3,7,8-D4 1 unit of F4-8 emissions is equivalent to 0.08475 units of 2,3,7,8-D4 Table 3: Table 3 presents data on the partitioning of flue gas dioxin and furan emissions between the percentage in the gas phase and the percentage adsorbed onto the particulates in the flue gas. These data are based on test results from 6 different incinerators, using flue gas samples obtained downstream of any particulates control equipment. As seen in Table 3, about 80% of the dioxin and furan emissions appear in the gas phase and about 20% appear in the flue gas particulates. Table 4: Table 4 presents particulate emission size distribution data, based on the reported results from testing 2 incinerators equipped with fabric filter baghouses and 2 incinerators equipped with electrostatic precipitators. Figures 3A and 3D: Figure 3A presents the reported particle size di stribut i on data, which were then normalized to a common set of particle cutoff diameters from which an average distribution was obtained for each of the 2 dat a s ets (see Table 4). Figure 38 presents the 2 normalized distributions. |