Used as a reference standard in environmental testing to calibrate analytical instruments for detecting polychlorinated biphenyls (PCBs) in soil, water, and air samples. Commonly employed in gas chromatography and mass spectrometry to identify and quantify PCB contamination. Essential for monitoring industrial emissions, assessing hazardous waste sites, and ensuring regulatory compliance in environmental protection programs. Also used in research studies on persistent organic pollutants and their impact on ecosystems and human health.