Eating a tiny bit of a melamine, the chemical responsible for a global food safety scare, is not harmful except when it is in baby formula, U.S. food safety officials said Friday.

Melamine-tainted formula has sickened more than 54,000 children in China and is being blamed for the deaths of at least four tots. The chemical has also turned up in products sold across Asia, ranging from candies, to chocolates, to coffee drinks, that used dairy ingredients from China.

Authorities in California and Connecticut have found melamine in White Rabbit candies imported from China.

But infant formula made in the U.S. is safe, because manufacturers do not use any ingredients from China.

The Food and Drug Administration said Friday its safety experts have concluded that eating a very tiny amount of melamine — 2.5 parts per million — would not raise health concerns, even if a person ate food that was tainted with the chemical every day.

But officials stressed the scientific assessment does not mean that U.S. authorities will tolerate any melamine that is deliberately added to foods. In China, unscrupulous suppliers appear to have been adding melamine to make watered-down milk seem protein-rich in quality-control tests. That's because melamine is high in nitrogen, as is protein.

"If products are adulterated because they contain melamine, (authorities) will take appropriate actions to prevent the products from entering commerce," the FDA said in a statement. The agency said it was setting the 2.5 parts-per-million standard to address situations in which the chemical accidentally comes into contact with food, such as in cases where it is used for industrial purposes in a factory that makes food products.

Keep chemical out of U.S. formula
Officials also stressed that infant formula sold to U.S. consumers must be completely free of melamine.

"There is too much uncertainty to set a level in infant formula and rule out any public health concern," the FDA said.

Melamine first came to the attention of U.S. consumers last year, when it touched off a massive pet food recall. Chinese suppliers of bulk pet food ingredients were found to have been adding the chemical to artificially boost the protein readings of their products. Thousands of pets here were sickened, and hundreds are believed to have died.

Melamine is harmful to the kidneys. It can cause kidney stones as the body tries to eliminate it, and in extreme cases, life-threatening kidney failure.

美國食品安全局周五說，除非是嬰兒，食用微量的三聚氰銨（現在是全球食品安全機構的大敵）對身體無害。

感染三聚氰銨的配方奶粉致使中國至少54000人生病，并因使至少4名嬰兒死亡而飽受遣責。這種化學物質也在亞洲以外的市場上出現，包括糖果、巧克力、咖啡飲料均使用了中國奶制品。加州和康州當局均從進口中國的大白兔奶糖中檢出了三聚氰銨。

但美國生產的嬰兒配方奶粉是安全的，因為制造商未使用進口自中國的原料。

食品和藥品局周五說安全專家已經得出結論，食用微量的三聚氰銨（每公斤2.5毫克）不會引起健康問題，即使一個人每天的食物中含有這種劑量的話。

但該官員又強調說科學評估并不意味著當局榮忍任何三聚氰銨被故意填加到食品中。在中國，極不道德的供應商似乎一直將三聚氰銨填加到含水的牛奶中以使其在質量檢測中蛋白質含量達標。這是因為三聚氰銨和蛋白質一樣含氮量比較高。

食品和藥品管理局在聲明中說：“如果任何產品摻入三聚氰銨，當局將采取適當措施阻止其進入市場。”發言人說正在設定百萬分之2.5的標準通知各單位，因為這種化學品會偶然進入進入供應環節，例如因工廠的食品裝箱時滲入。

讓三聚氰銨遠離美國配方奶粉官員還強調說美國市場上的嬰兒配方奶粉必須完全不含任何三聚氰銨。

該官員稱：“設置嬰兒配方奶粉級別和消除任何公眾對健康的關心有太多的不確定性。”

美國消費者關注三聚氰銨始于去年，那時大量寵物食品被召回。中國供應的大多數寵物食品中檢測出填加了三聚氰銨，以人為提高產品中的蛋白質含量。數以千計的寵物生病，據說幾百只死亡。

三聚氰銨對腎有害。當身體可能因為試圖消化它而引發腎結石，危險時可能危及生命。