Used as an internal standard in mass spectrometry for the accurate quantification of thiabendazole residues in food and environmental samples. Its deuterated structure allows for clear differentiation from the non-labeled compound during analytical testing. Commonly applied in pesticide residue analysis, particularly in fruits, vegetables, and soil, ensuring compliance with regulatory limits. Also utilized in metabolic studies to track the fate and degradation of thiabendazole in biological systems, including pharmaceutical research on absorption, distribution, metabolism, and excretion.