Melamine contamination has triggered another recall — this one involving several varieties of imported biscuits. Interfood Shareholding Company of Vietnam is recalling four varieties ofWonderfarm biscuits because of possible melamine contamination.

The Food and Drug Administration (FDA) said the recalled biscuits are sold in red metal cans. The specific products involved in this action are:

• Wonderfarm "Successful" Assorted Biscuits (UPC:8935001262091);

• Wonderfarm "Royal Flavour" Assorted Biscuits (UPC:8935001263098);

• Wonderfarm "Lovely Melody" Assorted Biscuits (UPC: 8935001263296);

• Wonderfarm "Daily Life" Assorted Biscuits (UPC: 8935001264200)

Interfood recalled the products after learning that samples of Wonderfarm's "Successful" Assorted biscuits — collected by the Minnesota Department of Agriculture — tested positive for melamine. The company expanded its recall after the "Royal Flavour," "Lovely Melody," and "Daily Life" biscuits also tested positive for melamine.

Interfood said it distributed the biscuits to several states. Wholesale distributors then sold the products to retail stores.

No reports of illnesses are linked to the tainted biscuits, the company said.

Consumers who purchased these products can return them to the store for a full refund.

For more information about this recall, customers can contact the company at Anthony.ma@jaimporters.com, or call 323-780-3998

Melamine is a chemical used to make plastics and fertilizers. It is not approved for use in human or animal foods marketed in the United States — and manufacturers are not allowed to deliberately add it to any food for U.S. consumers.

Concerns about melamine — and its intentionally adulteration in imported foods — have repeatedly surfaced in the past year.

Just a few months ago, Chinese officials discovered melamine in powered infant formula made in that country. Officials learned some dairy plants purposely added the chemical to milk products to make them appear to have higher protein levels.

That contamination is blamed for the deaths of at least six babies in China and the illnesses of thousands of other infants.

Doctors say melamine can cause kidney stones and lead to kidney failure.

China's melamine-tainted milk scandal has since spread from infant formula to dozens of other food products sold around the world, including candy, coffee, and pretzels.

Melamine is also blamed for the deaths and illnesses of thousands of dogs and cats in the United States in 2007.

FDA officials discovered the chemical in imported wheat gluten from China used to make dog and cat food. Those findings triggered the largest pet food recall in U.S. history.

Although melamine is not supposed to be in animal or human food, the FDA recently concluded that levels below 2.5 parts per million (ppm) do not raise health concerns. The only exception is infant formula.

The FDA now says melamine levels of 1 ppm in infant formula are safe. That is a reversal of the zero tolerance policy for melamine the agency adopted in October.

At that time, the FDA said it was "unable to establish any level of melamine and melamine-related compounds in infant formula that does not raise public health concerns."