The origin and safety of food has come under the spotlight recently with the discovery of the banned chemical melamine in imported feed for US livestock.

The call, made to Congress, comes from Ranchers-Cattlemen Action Legal Fund (F-Calf). They claim that concerns raised over the safety of imports have increased, while inspections have fallen.

In a letter to Rep. Rosa DeLauro and Sen. Herb Kohl, who both chair Agriculture subcommittees at the Food and Drug Administration (FDA), the group claims that while imports have doubled since 2000, inspections have fallen by 40 per cent.

The letter stated that food safety and integrity are in serious jeopardy because of uncertainties about the origin of imports.

"The pet food poisoning scandal has revealed how out-of-control the situation has become," the letter stated. "Rice, wheat and corn gluten have been systematically spiked with melamine to falsely increase lab tests for protein, without providing nutrition, and to gain higher market prices for the ingredients."

The chemical that was originally discovered in contaminated pet food has led to the deaths of hundreds of dogs and cats as a result. The scare widened in the US after it was found to have entered the human food chain after pet food scrap was used as a feed supplement at a number of hog and chicken farms.

Melamine is an industrial chemical found in plastics. The US found that the chemical had been fraudulently added to wheat gluten and rice protein from China. The country has now banned its exporters from using the chemical as an additive to boost protein levels in feeds.

Following the outbreak, the United States Department of Agriculture estimates it has detained 46 Chinese shipments of vegetable proteins. With no testing certification yet received to confirm melamine is present, all restricted shipments continue to remain in USDA detention.

According to a recent report by the Washington Post, the USDA last month seized over 1,000 shipments of tainted Chinese dietary supplements, toxic cosmetics and counterfeit medicines.

Although more shipments are being scrutinized by authorities following the melamine scare, F-Calf claims the current inspection framework is not working and consumers should be given the choice of determining the origin of the food they eat.

"Consumers do not want to, and cannot, rely entirely on the government," the letter stated. "A meaningful first step is to immediately implement mandatory country of origin labeling for meat and produce. Consumer choice is irrevocably connected with consumer safety."

Mandatory country-of-origin labeling was approved by Congress in 2002 and has been implemented successfully for seafood, while its application to other food groups has been delayed.