By-Side Impurities in Chloronaphthalene Mixtures of the Halowax Series: All 12 Chlorobenzenes

Abstract

Total chlorobenzene content of the Halowax mixtures ranged from 1100 to 9800 ng/g. A lower chlorinated Halowax 1031 and 1000 were a several times more contaminated with chlorobenzenes than higher chlorinated Halowax 1001, 1099, 1013, 1014, or 1051. Depending on the type of the Halowax mixture the most contributing amongst of chlorobenzene homologue groups were di-, tetra-, penta-, and hexa-CBz. A dominance and specific profile of 1,4-DiCBz, PeCBz, and HCBz were characteristic to Halowax 1001, 1099, 1013, 1014, and 1051, while for other formulation the CBzs profile varied, and 1,2,3,4-TeCBz (Halowax 1031) and 1,4-DiCBz (Halowax 1000) predominated. A steric hindrance effect seems to direct a preferential by-side formation of 1,4-DiCBz and further also of PeCBz and HCBz due to relatively elevated temperature as well as duration time of synthesis for five most chlorinated (49-70 Cl%) chloronaphthalene Halowax formulations.

By-Side Chlorobenzenes and Chlorophenols in Technical Chlorobiphenyl Formulations of Aroclor 1268, Chlorofen, Clophen T 64, Kanechlor 600, and Kanechlor 1000

“…The compositional profile of CBz of Aroclor 1268 is somewhat similar to that reported for some highly chlorinated technical chloronaphthalene formulations such as Halowax 1051 and 1099. [2,3] The compositional profile of CBzs of Kanechlor 600 is also different from those of Chlorofen, Clophen T 64, and Kanechlor 1000. The abundance of more chlorinated homologue groups is somewhat larger.…”

“…[2] For the Halowaxes, depending on the degree of the mixture chlorination, 1,4-DiCBz, 1,2,3,4-TeCBz, 1,2,3,4,5-PeCBz and 1,2,3,4,5,6-HxCBz were the most contributing among the CBzs found. By examing the Halowax formulations, it was concluded that after initial by-side formation of monochlorobenzene, and due to a steric hindrance effect further chlorine atom entering the ring is substituted in para position, i.e., 1,4-DiCBz is formed preferentially, and further PeCBz and HxCBz.…”

“…By examing the Halowax formulations, it was concluded that after initial by-side formation of monochlorobenzene, and due to a steric hindrance effect further chlorine atom entering the ring is substituted in para position, i.e., 1,4-DiCBz is formed preferentially, and further PeCBz and HxCBz. [2] The CBz profile of Aroclor 1268 with 1,2,4-TrCBz and 1,2,3,4,5,6-HxCBz as highly contributing constituents varies largely compared to that of Chlorofen and the Halowax formulations. [2] The CBz profile of Kanechlor 600 was quite different from these technical chlorobiphenyl mixtures, but also of technical chloronaphthalene Halowax formulations.…”

“…[2] The CBz profile of Aroclor 1268 with 1,2,4-TrCBz and 1,2,3,4,5,6-HxCBz as highly contributing constituents varies largely compared to that of Chlorofen and the Halowax formulations. [2] The CBz profile of Kanechlor 600 was quite different from these technical chlorobiphenyl mixtures, but also of technical chloronaphthalene Halowax formulations. The most abundant homologue group was TrCBzs, followed by TeCBzs.…”

“…[1] It has been clarified recently that technical chloronaphthalene Halowax formulations, which were precursors to chlorobiphenyl mixtures, are contaminated with numerous by-side chemicals including chlorobenzenes (CBzs), chlorophenols (CPhs), chlorodibenzofurans (CDFs), chlorodibenzo-p-dioxins (CDDs), and CBs. [2][3][4][5][6] Apart from resistance to degradation and highly toxic CDD/Fs or planar CBs also chlorobenzenes and chlorophenols are environmentally relevant pollutants. [2,3,[7][8][9][10][11][12] In this study a full qualitative and quantitative characteristic were elucidated of 12 chlorobenzene and 19 chlorophenol congeners theoretically possible that contaminate relatively highly chlorinated technical CB formulations of Aroclor 1268 (USA), Chlorofen (Poland), and Kanechlor 600 (Japan), as well as Clophen T 64 (Germany) and Kanechlor 1000 (Japan).…”