[Cannabis poisoning after eating salad]

We describe 4 patients who suffered gastrointestinal disorders and psychological effects after eating salad prepared with hemp seed oil. The concentration of tetrahydrocannabinol (THC) in this oil far exceeded the recommended tolerance dose. Our observations prompted the Swiss Federal Office of Public Health to publish warnings in the press concerning consumption of this oil. We describe the symptoms of orally ingested THC and point out unresolved problems connected with food containing hemp.