National Consumers League


NCL Food Issues

Are shipping pallets exposing our food to contamination?

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Could we be better transporting our food supply?Government, health groups, and the food industry are all working together to improve the safety of America's food supply, from laws and regulations at the factory and farm level to promoting good cooking and storage practices at home. But what about the steps in between: could the sanitation of our food transportation be improved?

The government, consumer, public health, and victims groups, and even members of the food industry all recognize the need to improve the safety of the food sold and eaten in the United States, at every step of the way along the path from “farm to fork.” Regulations and inspections help ensure food safety at the farm and factory stage, and restaurant workers and consumers can do their part to reduce cross-contamination and unsafe cooking practices inside and outside the home. But the area in between – the transportation of food from production to purchase point – remains largely overlooked and under-regulated.

The pallets used to ship our food across the country play a crucial role in that food transportation system; however, several different aspects of pallet use and storage present potential food safety concerns. If a pallet is absorptive – i.e., has the capacity to absorb water and harbor bacteria – or difficult or impossible to fully clean, it could contaminate food products like fresh produce or meat. A pallet that carries raw seafood on ice to a given destination, then is used to transport heads of lettuce or apples to the next, could potentially contaminate that produce and lead to foodborne illness.

In late April 2010, NCL conducted exploratory testing of pallets to determine whether they are potential carriers of pathogens, as concerns grow about the link between pallets and contamination of food and pharmaceuticals. We tested pallets for foodborne pathogens, including E. coli and Listeria. The findings were alarming: 10 percent of the wood pallets tested had E. coli present (though not the most virulent strain, E. coli O157:H7). In a letter to the FDA, NCL described the results of its testing of wood and plastic pallets used to transport food in the greater Houston, Texas and Miami/Tampa, Florida, areas. In all, NCL tested 70 wood pallets and 70 plastic pallets. NCL shipped the samples overnight to an independent microbiology lab that provides testing services for a wide array of commercial, industrial, regulatory, and law enforcement clients.

No matter what they’re made from (wood or plastic), any pallet that is not properly cleaned between trips increases the likelihood of cross-contamination. Storing a pallet outside, in unsanitary areas, in places accessible to vermin, or near potential contaminants increases the chances that the pallet could harbor dangerous pathogens. In conducting our testing, we observed that wood pallets – which we found to have a higher incidence of pathogens – are more often stored outside and exposed to weather, rodents, bird droppings, and insects. Among additional considerations is the use of damaged wood pallets; splinters or sharp points can damage the packaging of products, creating an entryway for pathogens from which sealed products would otherwise be protected.

In addition to the presence of E. coli, 2.9 percent of the wood pallets tested positive for Listeria, and half of these, when further tested, contained Listeria monocytogenes, one of the most virulent foodborne pathogens. This strain of Listeria is linked to a 20 to 30 percent rate of clinical infections resulting in death and causes approximately 2,500 illnesses and 500 deaths in the United States every year. Listeriosis is more likely to cause death than any other foodborne bacterial pathogen. Of the 70 plastic pallets tested, 1 – or 1.4 percent – came back positive for E. coli. None of the other plastic pallets tested positive for pathogens. Finally, high aerobic plate counts, which reflect unsanitary conditions of the pallets, were found on approximately one third of the wood pallets and one fifth of the plastic pallets.

In its letter to FDA Commissioner Margaret Hamburg, NCL urged the agency to do its own testing and called on FDA to set standards that will help to ensure that pallets are cleaned and stored properly, thus minimizing the possibility that they will be implicated in the spread of foodborne illness.

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