An autopsy case of acute butane intoxication by using gas cylinder of portable stove.

We report a case of fatal acute butane poisoning in a woman in her 80 s, who was found in a bathtub filled with butane gas. Five artificially punctured liquefied petroleum gas (LPG) cartridges were discovered within the bathtub. Forensic autopsy revealed no significant traumatic injuries or pathological findings sufficient to explain the cause of death. Toxicological analysis identified butane and diphenhydramine (DPH) in the blood, urine, and various organs. The peripheral blood concentrations of butane and DPH were 2.95 μ g/ml and 3.56 μ g/ml, respectively. While the DPH concentration was within the toxic range, it did not reach fatal levels independently. Given that the urinary DPH concentration (0.25 μ g/ml) was approximately 1/14th of the blood concentration, it was concluded that death occurred due to butane toxicity during the absorptive phase of DPH. Based on the toxicological findings and the scene circumstances, the cause of death was determined to be acute butane poisoning.