A fatal intoxication from ingestion of 2-methyl-4-chlorophenoxyacetic acid (MCPA)

We report a fatal intoxication case by the ingestion of an herbicide, 2-methyl-4-chlorophenoxyacetic acid (MCPA). A 23-year-old male was found dead in his car. The forensic autopsy revealed no remarkable morphological changes. However, in a toxicological screening test, MCPA was qualitatively detected from the extracts of stomach contents. Then MCPA in the extract of each body fluid and organ tissue was determined by gas chromatography-mass spectrometry with trimethylsilyl-derivatization as follows (microg/g): 888.3 in the heart blood, 578.1 in the peripheral blood, 52.2 in the urine, 770.9 in the brain, 1362 in the right lung, 1135 in the liver, 755.5 in the right kidney, and 10,200 in the stomach contents. These data strongly suggested that the male orally ingested MCPA. Moreover, p-chloro-o-cresol (4-chloro-2-methylphenol) was also determined in the body fluids and organ tissues, suggesting a metabolite of MCPA. From these toxicological data, together with autopsy findings, the cause of his death was diagnosed as acute MCPA poisoning.