Deaths involving 1,1-difluoroethane at the San Diego County Medical Examiner's Office.

Intentional abuse of 1,1-difluoroethane has been reported to cause transient symptoms such as confusion, tremors, pulmonary irritation, loss of consciousness and, rarely, coma. In the last five years, 17 cases from the San Diego County Medical Examiner's Office showed the presence of 1,1-difluoroethane in postmortem tissues, and the gas was cited in the cause of death in 13 of those cases. Detected during routine ethanol screening, 1,1-difluoroethane was evaluated for concentrations in peripheral blood, central blood and vitreous humor by a slightly modified method published by Avella et al. In many cases, death from abuse of 1,1-difluoroethane seemed to occur within minutes of intentional abuse; large concentrations (>100 mg/L) of the gas were still in the blood. It is important that forensic toxicology laboratories have routine screening procedures to detect 1,1-difluoroethane because cases exist in which evidence of use from cans may not be present in proximity to the decedent, or may be undiscovered in the debris of a motor vehicle accident. It is also important to quantify concentrations of 1,1-difluoroethane in both peripheral blood and central blood, whose ratio may be useful in interpreting how recently the use of the 1,1-difluoroethane occurred.