Han Ximin

SHENZHEN’S health authorities have identified sodium nitrite as the cause of a mass food poisoning incident that left two people dead and 61 others in hospital Saturday.

The health bureau of Longgang District said yesterday food and water samples taken from the restaurant, in which the victims had eaten, were found to be contaminated with the chemical.

But police have ruled out the possibility that the chemical was mistaken for salt or sugar by the chefs.

Fifty-four had been discharged from hospital by 9:45 p.m. yesterday, leaving 7 — all described as stable — still receiving treatment, according to the two hospitals where they were hospitalized. All 61 survivors are employees of Shenzhen-based carmaker BYD’s factory in Longgang, as were the two deceased.

Local police and health officers have begun questioning the manager of the restaurant, patients and employees of BYD.

The sixty-three victims vomited, felt abdominal pain and showed other symptoms of poisoning at around 11 a.m. Saturday after having breakfast at the restaurant, which is located behind the factory.

One later died at a nearby community clinic while another died at Longgang Central Hospital.

BYD has warned its employees not to dine at nearby restaurants.

“The factory canteen was closed at 8:30 a.m. and I went to the restaurant with five colleagues for breakfast. We ordered eggplants, tomatoes, green peppers, soybean curds and rice noodles,” said a worker surnamed Du, who was receiving treatment at Longgang Central Hospital.

The district authorities have closed nearly 20 unlicensed eateries after the accident. The 20 eateries had earlier been closed one month before the Spring Festival for operating without licenses, but they reopened after the holidays, according to the workers.

Sodium nitrite, similar in appearance to salt, is used as an industrial color fixative, but is also used in small amounts as a meat preservative.

Health experts have warned that 0.2 grams of sodium nitrite can poison an adult and three grams is enough to kill.

In January last year, more than 300 workers of BYD’s Shanghai factory were hospitalized after lunch at the factory canteen. Twenty-two were confirmed to have been poisoned by undercooked beans.

Founded in 1995, the Shenzhen-based BYD, listed in Hong Kong in 2002, is an automobile manufacturer and also China’s largest mobile phone battery maker, with more than 120,000 employees across the country.