Beijing's health authorities have banned all schools in the city from providing snap beans to students, in order to prevent food poisoning, the Beijing Morning Post reports. Cafeterias at all schools, including universities, high schools and primary schools, are forbidden to cook snap beans, in an effort to make sure that no bean-related cases of food poisoning take place, the Beijing Municipal Bureau of Heath said on Tuesday at a meeting with more than 100 headmasters. Many cases of food poisoning have occurred in Beijing schools as a result of snap beans which have not been cooked sufficiently. In certain cases, hundreds of students have been left injured as a result of food poisoning. According to the Bureau of Health, the headmasters will be "the first persons responsible" for food safety issues. Students and their guardians will be invited to supervise and inspect the school cafeteria. Snack counters within schools will also come under food safety supervision. Experts say snap beans contain erythrocyte condensation and saponins. These are poisonous chemicals and cannot be removed until the beans are heated above 100 degrees centigrade for more than 10 minutes. School cafeterias usually use large pots to cook food, which makes it difficult to heat the beans evenly.