Used primarily as a reference standard in environmental testing to detect and quantify polychlorinated biphenyl (PCB) contamination in soil, water, and biological samples. Its stable composition makes it suitable for calibration in gas chromatography and mass spectrometry analyses. Due to its persistence and toxicity, it is also studied to understand the fate and behavior of legacy pollutants in ecosystems. Strict handling protocols are followed given its classification as a persistent organic pollutant with potential health and environmental risks.