Some forms of sushi, notably those containing pufferfish fugu and some kinds of shellfish, can cause severe poisoning if not prepared properly. Particularly, fugu consumption can be fatal. Fugu fish has a lethal dose of tetrodotoxin in its internal organs and, by law in many countries, must be prepared by a licensed fugu chef who has passed the prefectural examination in Japan. The licensing examination process consists of a written test, a fish-identification test, and a practical test that involves preparing the fugu and separating out the poisonous organs. Only about 35 percent of the applicants pass.