A sudden death related to 1,1-difluoroethane inhalation—A case report and brief review of the literature

Abstract

1,1-difluoroethane (DFE; HFC-152a, Freon® 152a) is used as a propellant in gas dusters, and it is sometimes misused as a recreational “drug” to induce an altered mental state. Herein we describe the forensic autopsy case of a man who may have died due to DFE inhalation. No specific external injuries were detected during the autopsy, and internal examination revealed pulmonary edema and intrapleural effusion. Gas chromatography-mass spectrometry analysis detected DFE in the decedent’s heart blood. The DFE concentrations (μg/mL or g) in blood and tissue samples were 74.8 in heart blood, 137.4 in femoral blood, 58.8 in lung, 108.7 in the liver, and 89.5 in muscle. In brain and adipose the DFE levels exceeded the upper limit of quantification (150 μg/g). The DFE concentrations in the present case did not exceed those in previous cases of poisoning with DFE alone, and they were similar to those of previous cases involving combined factors. Considering the autopsy findings and the DFE concentrations in the blood and tissue samples, we concluded the cause of death was drowning due to loss of consciousness resulting from DFE inhalation. The difference between DFE concentrations in heart blood and femoral blood suggests that he may have died after he stopped inhaling DFE rather than during inhalation. While the number of poisoning deaths due to DFE in Japan cannot be reliably ascertained, the regulation of certain drugs such as nitrite esters (RUSH®) may have inadvertently resulted in some people misusing DFE, which is more accessible than illicit drugs.

Keywords

• 1,1-difluoroethane
• Antemortem pharmacokinetics
• Freon
• Postmortem distribution
• Volatile substance misuse