Synonyms: 1,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin;1,2,3,4,6,7,8-Heptachlorodibenzo[1,4]dioxin; 1,2,3,4,6,7,8-Heptachlorodibenzo[b,e][1,4]dioxin;1,2,3,4,6,7,8-Heptachlorodibenzodioxin; 1,2,3,4,6,7,8-HpCDD; D 73;Heptachlorodibenzo-p-dioxin; HpCDD; PCDD 73