Used as a reference standard in environmental testing to quantify the presence of 2,4'-DDD, a metabolite of the pesticide DDT, in soil, water, and biological samples. It ensures accurate calibration of analytical instruments like gas chromatographs and mass spectrometers. Commonly applied in monitoring pesticide degradation, assessing contamination levels, and evaluating ecological and human health risks in exposed areas. Also used in research studies focused on persistent organic pollutants and their long-term environmental impact.