Tests on the feed showed the concentration of melamine — a chemical used to make plastics and fertilizers — was very low and did not pose a significant threat to humans, U.S. government scientists said.

"We literally found that the dilution is so minute, in fact in some cases you can't even test and find melamine any more in that product," Agriculture Secretary Mike Johanns said in Chicago.

Food safety concerns grew after U.S. officials found that some small manufacturing plants had been incorporating pet food into their animal feed before tests showed the pet food was contaminated.

Source: Cbc.ca

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