Dioxin-like PCBs,WHO + ISO/DIS 17858 Chiron No. Compound PCB No. 2006.12 3,3´4,4´-Tetrachlorobiphenyl PCB-77 2007.12 3,4,4´,5-Tetrachlorobiphenyl PCB-81 2008.12 2,3,3´,4,4´-Pentachlorobiphenyl PCB-105 2009.12 2,3,4,4´,