Suicide by plastic bag suffocation combined with the mixture of citric acid and baking soda in an adolescent

We describe a case of suicidal asphyxiation using a plastic bag combined with carbon dioxide (CO₂) gas. A 20-year-old male, whose head was covered with a plastic bag, was found dead in his room. In the plastic bag, there were two glass-made cups containing liquid-like substance. Through crime scene investigation by police staffs, a bottle of citric acid and a box of baking soda were also discovered in his room. The forensic autopsy revealed that there were neither lesions nor injuries in all of the organs. Moreover, any drugs and poisons could not be detected in blood samples. Based on autopsy findings and crime scene investigation, the cause of death was diagnosed as acute asphyxia due to CO₂ intoxication by the mixture of citric acid with baking soda in the plastic bag. To the best of our knowledge, there are no medical literatures describing plastic bag suffocation combined with CO₂ gas generated from citric acid and baking soda, which has been widely distributed as suicidal means through websites. This case report promotes forensic pathologists and medical coroners to emphasize that the Internet has a crucial role on a source of suicidal information or a promoter of suicide all over the world.