ඒවා අශුද්ධ දුසිම ලෙස හැඳින්වේ. aldrin, chlordane, ddt, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, polychlorinated biphenyls, polychlorinated dibenzo - p - dioxins, polychlorinated dibenzofurans, හා toxaphene.