In the wake of the recent recall ofE. coli-tainted romaine lettuce, theNational Consumers League(NCL), Washington, D.C., said it is urging theU.S. Food and Drug Administration (FDA) to set minimum sanitary and safety standards for the "unregulated but crucial" pallets that are used to transport food throughout the United States.

NCL said its request follows its own "exploratory tests" on pallets to determine whether they are potential carriers of pathogens, as concerns grow about the link between pallets and contamination of food and pharmaceuticals. NCL said it tested pallets for foodborne pathogens, includingE. coli andListeriaand found that 10 percent of the wood pallets tested hadE. colipresent (though not the most virulent strain,E. coli O157:H7).

In a letter to the FDA, NCL described the results of its exploratory testing of wood and plastic pallets used to transport food in the greater Houston, Texas and Miami/Tampa, Florida, areas. Testing was conducted in late April and included 70 wood pallets and 70 plastic pallets in total. 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.

"We believe it is essential to ensure that pathogens are not introduced at any step along the food transport system, from farm to fork. Our testing of pallets has shown that these relatively unregulated but crucial parts of the food transportation system can and do harbor dangerous pathogens that could potentially contaminate the food supply," said Sally Greenberg, the group's executive director.

In addition to the presence of E. coli, 2.9 percent of the wood pallets tested positive forListeria, and half of these, when further tested, containedListeria monocytogenes, one of the most virulent foodborne pathogens. This strain ofListeriais 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.Listeriosisis 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 forE. 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.

As the recent outbreak of E. coli underscores, the threat of foodborne illness remains a serious concern in the United States.

"Looking at the safety of pallets is crucial. Even if farmers, manufacturers, retailers, and consumers were all to follow food safety plans and practices to the letter, the introduction of dangerous pathogens into the food supply during transport could negate these efforts…With approximately two billion pallets currently in circulation in the United States, the presence of dangerous pathogens on even a small percentage of those pallets presents a potential threat to the safety of the food supply," wrote Greenberg in her letter to the FDA.

NCL said 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 heads of lettuce or apples to the next, could potentially contaminate that produce and lead to foodborne illness. In a just-issued report prepared for the FDA, Eastern Research Group, Inc. highlights the use of "good quality pallets" as a preventive measure. The agency has said it will use the report to inform the development of new rules to increase the safety of food during transport.

Furthermore, regardless of the materials from which it is made, 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.

Said NCL, "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."

NCL said its findings build on the growing concern about the potential dangers of unregulated pallets to consumers. In January of this year, McNeil Consumer Healthcare issued a recall of several of its over-the-counter products reported to have a moldy odor and that, in some individuals, were thought to have caused gastrointestinal distress.

In a press release dated January 15, the company stated: "McNeil Consumer Healthcare has determined that the reported uncharacteristic smell is caused by the presence of trace amounts of a chemical called 2,4,6-tribromoanisole (TBA). This can result from the breakdown of a chemical that is sometimes applied to wood that is used to build wood pallets that transport and store product packaging materials." The FDA issued the same statement on its Web site.

NCL said it is urging the FDA to do its own testing and 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.