Used primarily as a reference standard in environmental testing laboratories to detect and quantify polychlorinated biphenyl (PCB) contamination in soil, water, and biological samples. Its stable structure allows for reliable calibration in gas chromatography and mass spectrometry analyses. Due to its persistence and toxicity profile, it also serves in research studying the fate, transport, and degradation of chlorinated organic pollutants in ecosystems. Handling requires strict containment due to environmental and health risks.