Zyklon B is was used to kill people during the holocaust and is no longer used. When Zyklon B was being used doctors never had a patients coming to them with Zyklon B poisoning because those who were poisoned were locking inside a gas chamber and did not survive longer than 15 minutes. Prussic acid passes through the mucous membranes and the skin, but principally through the lungs, into the blood. It blocks the process by which oxygen is released from red blood corpuscles and the result is a sort of internal asphyxiation. This is accompanied by symptoms of injury to the respiratory system, combined with a feeling of fear, dizziness and vomiting. Once the gas chambers were opened all that was left of was corpse, dentists then removed fingers and golden teeth.