ii. Dioxins (sum of polychlorinated dibenzo-para-dioxins ( PCDDs) and polychlorinated dibenzofurans ( PCDFs), expressed as World Health Organisation ( WHO) toxic equivalent using the WHO-toxic equivalency factors ( WHO- TEFs).
iii. Of the 209 PCB congeners, the most toxic are the so-called 'dioxin-like' PCBs ( DL-PCBs). The DL- PCBs are the four non- ortho ( CB77, 81, 126, and 169) and eight mono- ortho ( CB105, 114, 118, 123, 156, 157, 167, and 189) congeners. DL-PCBs are stereo-chemically similar to 2,3,7,8-tetrachlorodibenzo- p-dioxin ( TCDD) and, therefore, have similar toxic and biological responses to those of dioxins.
iv. The seven ICES (International Council for the Exploration of the Sea) PCBs ( CB28, 52, 101, 118, 153, 138, and 180) were recommended for monitoring by the European Union Community Bureau of Reference; these congeners were selected as indicators of wider PCB contamination due to their relatively high concentrations in technical mixtures and their wide chlorination range (3-7 chlorine atoms per molecule). The ICES 7 PCBs have been part of the OSPAR Co-ordinated Environmental Monitoring Programme ( CEMP) since 1998. MPCs have been set for the ICES 6 (excludes CB118 which is classed as a DL-PCB).
v. Metals (cadmium, mercury and lead) in sediment and biota ; PAHs (anthracene, benz[ a]anthracene, benzo[ ghi]perylene, benzo[ a]pyrene, chrysene, fluoranthene, indeno[1,2,3- cd]pyrene, pyrene and phenanthrene) in biota and sediment; PCBs ( ICES7- CB28, 52, 101, 118, 138, 153 and 180) in biota and sediment; brominated flame retardants (hexabromocyclododecane ( HCBD) and BDE28, 47, 66, 85, 99, 100, 153, 154 and 183 in biota and sediment, and BDE 209 in sediment).
vi. This is the MPC from 1881/2006, this was amended to 6.5 pg g -1 TEQ wet weight in 1259/2011