Urethane-(ethyl-d5) is primarily used as a labeled internal standard in analytical chemistry, particularly in mass spectrometry and nuclear magnetic resonance (NMR) studies. Its deuterated form allows for precise quantification and identification of urethane and related compounds in complex biological or chemical matrices. This compound is especially valuable in pharmacokinetic and metabolic studies, where tracing the distribution and breakdown of urethane in organisms is essential. Additionally, it aids in research focused on understanding the mechanisms of urethane-induced carcinogenicity, providing insights into its metabolic pathways and interactions at the molecular level.