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.

美国食品安全局周五说，除非是婴儿，食用微量的三聚氰铵（现在是全球食品安全机构的大敌）对身体无害。

感染三聚氰铵的配方奶粉致使中国至少54000人生病，并因使至少4名婴儿死亡而饱受遣责。这种化学物质也在亚洲以外的市场上出现，包括糖果、巧克力、咖啡饮料均使用了中国奶制品。加州和康州当局均从进口中国的大白兔奶糖中检出了三聚氰铵。

但美国生产的婴儿配方奶粉是安全的，因为制造商未使用进口自中国的原料。

食品和药品局周五说安全专家已经得出结论，食用微量的三聚氰铵（每公斤2.5毫克）不会引起健康问题，即使一个人每天的食物中含有这种剂量的话。

但该官员又强调说科学评估并不意味着当局荣忍任何三聚氰铵被故意填加到食品中。在中国，极不道德的供应商似乎一直将三聚氰铵填加到含水的牛奶中以使其在质量检测中蛋白质含量达标。这是因为三聚氰铵和蛋白质一样含氮量比较高。

食品和药品管理局在声明中说：“如果任何产品掺入三聚氰铵，当局将采取适当措施阻止其进入市场。”发言人说正在设定百万分之2.5的标准通知各单位，因为这种化学品会偶然进入进入供应环节，例如因工厂的食品装箱时渗入。

让三聚氰铵远离美国配方奶粉官员还强调说美国市场上的婴儿配方奶粉必须完全不含任何三聚氰铵。

该官员称：“设置婴儿配方奶粉级别和消除任何公众对健康的关心有太多的不确定性。”

美国消费者关注三聚氰铵始于去年，那时大量宠物食品被召回。中国供应的大多数宠物食品中检测出填加了三聚氰铵，以人为提高产品中的蛋白质含量。数以千计的宠物生病，据说几百只死亡。

三聚氰铵对肾有害。当身体可能因为试图消化它而引发肾结石，危险时可能危及生命。