Great strides have been made with time, temperature, and basic food-hand ling practices. It is encouraging to see momentum growing and awareness broadening in the food service industry This improvement is a tribute to the efforts and dedication of environmental health and food safety professionals. Through effective food safety training, methods of cross-contamination are revealed and overcome, one layer at a time. Each new layer will expose the more detailed "back alleys" of commercial kitchens.
Perhaps one of the most overlooked of these back alleys for cross-contamination and general filth is cardboard. Without question, the cardboard crates for produce are traveling interstate roach motels. Cardboard boxes, with diminished light, moisture, and a food source, are an excellent breeding ground for cockroaches--and next best homes for cockroaches are the kitchens to which the boxes are delivered. With a microscope, it has been revealed that cardboard is also an excellent host to nearly all of the pathogens that cause foodborne illnesses. A recent laboratory study (Mann Biologic & Weiss, 1998) confirmed that E. coli, Salmonella, Listeria, and Shigella grow and flourish in cardboard under normal kitchen environment conditions. A separate study (Food Development Centre & McRae, 1997) tested random samples of cardboard film and foil cutter boxes taken directly from use in commercial kitchens. This study revealed up to 27 million colony-forming units per gram (CFU/g). That number is 27 times the amount of general bacteria and filth necessary to start food spoilage.
Examples of daily cardboard usage in most commercial kitchen food preparation areas include
* cutter boxes for plastic film and aluminum foil,
* pop-up dispensers for foil and wax sheets,
* food service food-handling-glove boxes,
* parchment paper boxes, and
* produce and meat boxes.
Most-Overlooked Vehicle for Contamination
Probably one of the most overlooked vehicles for cross-contamination is the cardboard cutter box for plastic film and aluminum foil. The boxes, found in virtually every retail food establishment, are nothing more than shipping containers with a blade attached. The cutter box is used as a piece of equipment on food contact surfaces. In a normal day, the box may be splashed with raw egg; juices from chicken, fish, and other meat; sanitation chemicals; and virtually any moisture found on and around cutting boards and work surfaces. Cardboard is absorbent and cannot be washed. Recognizing these cardboard cutter boxes as a piece of equipment used on food contact surfaces makes them a direct violation of Chapter 4 and Annex 3 of the Food Code (Food and Drug Administration [FDA], 200la, 2001b). Cardboard is a high-carbon medium. When combined with moisture at normal kitchen temperatures, it is a prime breeding ground for bacteria growth. If pathogens are present in raw or undercooked meat juice and so forth, and abs orbed into cardboard, their growth is virtually guaranteed.
In fact, in less than 24 hours, the various bacteria tested underwent a dense and vigorous growth. Any food service employee knows that the plastic film and foil boxes are carried by hand from work table to cutting board to shelf--or wherever--all day long, over and over again.
Method of Cross-Contamination
The following is a realistic scenario for an average day in a food service operation. Lacking an assigned space in any kitchen, the box usually starts its day where it was left the night before, on the prep table. The chef has a bucket with a stack of cardboard egg crates on the table. The cracking of 20 dozen eggs begins. The fast pace of this action inevitably creates splash and running of raw egg onto the table. Next to the chef, the prep cook has just sliced open the breakfast ham for steaks, and its juices are oozing onto the …