According to a North Carolina State University study based on video cameras placed in commercial kitchens, foodservice workers, on average, commit one act of cross-contamination with the potential of leading to illness per hour.


“Meals prepared outside the home have been implicated in up to 70 percent of food poisoning outbreaks, making them a vital focus area for food safety professionals,” says Ben Chapman, assistant professor and food safety specialist in the department of family and consumer sciences at NC State and lead author of the paper. “We set out to see how closely food handlers were complying with food safety guidance, so that we can determine how effective training efforts are.”


chef-cutting-meat-featured.jpgFor the study, researchers placed small video cameras in unobtrusive spots around 8 foodservice kitchens that volunteered to participate in the study, allowing the researchers to get firsthand data on food safety practices. There were as many as 8 cameras in each kitchen, which recorded directly to computer files and were later reviewed by Chapman and others. What they found demonstrates the need for new food safety-focused messages and methods targeting food handlers.


“We found a lot more risky practices in some areas than we expected,” Chapman said. Most previous studies relied on inspection results and self-reporting by food handlers to estimate instances of “cross-contamination” and found that cross-contamination was relatively infrequent, reported The Medical News.


However, Chapman’s study found approximately one cross-contamination event per food handler per hour, meaning the average kitchen worker committed 8 cross-contamination errors, which have the potential to lead to illness, in the course of the typical 8-hour shift.


Cross-contamination occurs when pathogens, such as Salmonella, are

transferred from a raw or contaminated source to food that is ready to

eat.  The study’s authors suggested the following as examples of cross-contamination:  using a knife to cut raw chicken and then using the same knife to slice a sandwich in half or raw meat dripping onto vegetables that are to be used in a salad.


“Each of these errors would have been deemed a violation under U.S. Food and Drug Administration Food Code inspection guidelines.  But more importantly, cross-contamination has the potential to lead to foodborne illnesses and has in recent outbreaks,” Chapman added. “And it’s important to note that the food-service providers we surveyed in this study reflected the best practices in the industry for training their staff.”


The study, published in this month’s issue of the Journal of Food Protection, confirmed the long-held belief that more food safety errors are made when the kitchen is busier.   Chapman stated that his team found an increase in cross-contamination events and a decrease in workers complying with hand washing guidelines during peak hours. 


Researchers didn’t just identify problems in the paper; they outlined solutions that can be applied to the food service industry.


“This study shows us that each food handler is operating as part of a system,” Chapman said, “and the food safety culture of the overall organization–the kitchen and the management–needs to be addressed in order to effect change. For example, the general manager of a restaurant could take steps to highlight the value his or her business places on food safety.” The researchers suggest that food safety training for kitchen staff needs to address the “team-like” nature of a commercial kitchen, rather than focusing on food handlers as individuals.


They also suggest installing hand sanitizer units in accessible areas of the kitchen to minimize the risk of foodborne illness. Hand sanitizer units may be effective for reducing the likelihood of transfer of some pathogens.


New procedures may include overhauling existing food-preparation schedules so that cooks face less time pressure during peak hours, making them less likely to make food safety mistakes.


The study, “Assessment of Food Safety Practices of Food Service Food Handlers: Testing a Communication Intervention,” was co-authored along with Chapman by Douglas Powell and Katie Filion of Kansas State University, as well as Tiffany Eversley and Tanya MacLaurin of the University of Guelph in Canada.