Chloroacetic acid-D3 is primarily used in research and development as a deuterated compound in analytical chemistry. It serves as a labeled internal standard in mass spectrometry and NMR spectroscopy, enabling precise quantification and tracking of chemical reactions. This compound is particularly valuable in metabolic studies and environmental analysis, where it helps trace the pathways and degradation of chloroacetic acid derivatives. Its deuterium labeling ensures minimal interference with natural isotopes, providing accurate and reliable data in complex biological and chemical systems.