Hidden danger
In China, the practice of using nitrite to cook meat has a history of over 800 years. In the Southern Song Dynasty (1127-1279), ancient people used saltpeter that mainly contained nitrate to make hams. It was discovered that nitrite functions excellently in preventing meat products from decaying, while also improving their luster and taste.
However, it gradually became clear that nitrite is poisonous if overused, and doctors and scientists have warned of the hidden danger in eating too much preserved food such as pickles and cured meat. Even some cooked food that has been stored can produce nitrite with time, so it is not advised to eat leftovers.
Food poisoning has become a thorny issue in Chinese society. Since 2005, eight nitrite poisoning cases have been reported, claiming the lives of 100 people. The range of poisoned foods has included milk, vinegar, canned meat and bird's nests, all tainted with nitrite.
On November 30, 2010, more than 100 workers suffered from vomiting and diarrhea at a factory in Shanghai, and were diagnosed with acute food poisoning. In April 2011, three children died and 35 others were sickened by milk tainted with nitrite.
Nevertheless, reports last month of high nitrite content in some bird's nest products have done little to dim demand for the delicacy in China.
Supply chain out of control
On September 6, 2011, the Ministry of Health released a notice warning the public of the potential danger caused by nitrite in food. 45 people died from food poisoning, mostly from toxic chemicals, in the first six months of 2011, according to the ministry.
In the case of the poisoned chicken, Zhang Jicun revealed that he had bought the sodium nitrite from a nearby company selling food additives located on the south Fourth Ring Road in Beijing. When Zhang purchased the chemical, he was told by a salesclerk that about one to three grams of sodium nitrite should be put into every 50 kilograms of meat.
However, Zhang did not read the instructions carefully before using the chemical.
Though the national standard for the maximum amount of food additives has been strictly regulated, many food suppliers are negligent and use chemicals carelessly. In 2000, the Beijing local government launched a campaign to crack down on the illegal use of nitrite, but the ban had a short-lived affect – there is no severe punishment for such behavior according to the law.
Experts say the problem of nitrite poisoning mainly lies in the excessive use and abuse of it, since food manufacturers usually add more to entice customers. Because of this, the public should use caution when buying food, and choose products that are healthier, not just tastier.
