Local health authorities have closed down a factory canteen in Shenzhen following a mass food poisoning that befell 308 factory workers on Wednesday.

The canteen, run by a Hong Kong-invested company that produced hardware and plastic in the outer Longgang District in the southern Guangdong Province boom city, was suspected to have served undercooked kidney beans at lunch on Wednesday.

Starting that afternoon, workers complained of headache, nausea and vomiting. They were sent to five local hospitals for treatment.

All the patients were allowed to go home by Thursday night, a spokesman with the local health bureau said.

In a hygiene checkup following the accident, investigators found the canteen didn't have a fridge or any shield to keep insects from its food.

The accident triggered a hygiene overhaul at staff canteens in Longgang District, a factory area with more than two million migrant workers.

Experts said kidney beans contained lectin, a toxic agent that could cause diarrhea if they weren't heated thoroughly. School and factory canteens were normally advised not to serve the beans.

Undercooked kidney beans had hospitalized 248 teenage students in the southwest Yunnan Province last month.

(Xinhua News Agency January 11, 2008)