1,2,3-Trichloro-5-(3,4-dichlorophenoxy)benzene is an intermediate in synthesizing 2,3,4,7,8-Pentachlorodibenzofuran (P237975), a toxic polychlorinated dibenzofurans (PCDD/F), detected in domestic meat and poultry. It can be used as purified standards for analytical, toxic, and biological studies of these environmental contaminants.