Used primarily in industrial applications as an intermediate in the synthesis of polychlorinated biphenyl (PCB) mixtures, this compound was historically found in electrical equipment such as transformers and capacitors due to its chemical stability and insulating properties. Its presence in such applications has been discontinued in many countries because of environmental persistence, bioaccumulation concerns, and toxicity. It may still be encountered in legacy systems or as a contaminant in environmental samples. Research applications include use as a reference standard in analytical studies monitoring PCB degradation and environmental contamination.