Risk of salmonella, norovirus and cyclospora transfer
GUELPH, ON, Oct. 10, 2013 /CNW/ - A new study indicates that Reusable
Plastic Containers (RPCs) used to ship fruit and vegetables in Canada
pose a risk for contamination.
The report, developed by a University of Guelph researcher, calls the
possibility for contamination a significant concern. "The main outcome
of the study is that the RPCs meant to be delivered in a sanitary
condition were not effectively cleaned. From a food safety perspective
this could mean that pathogens such as salmonella, norovirus and
cyclospora could be transferred to produce," explains Keith Warriner,
author of the study.
Warriner, who is the Food Safety and Quality Assurance Program Director
at the University of Guelph adds that, "in addition to human pathogens,
it is also possible that plant pathogens such as Erwinia, Pseudomonas,
Xanthomonas and Ascomycetes could be transferred, thereby resulting in
premature spoilage of produce."
In Canada some retailers demand farmers ship fruit and vegetables, from
the farm to the store, using RPCs. The containers are rented by farmers
to ship their produce and then returned to the United States for
cleaning. In Ontario, for example, RPCs are shipped to Chicago for
Containers at Ontario and Quebec farms were tested for overall sanitary
status (visual inspection and ATP testing), in addition to bacterial
counts (total aerobic counts) that included potential fecal indicators
(enterobacteriaceae and coliforms). Collectively, 64% of all RPCs
failed in terms of sanitary standards and 56% of trays had a higher
aerobic count than expected on a cleaned surface. Trays were sampled as
delivered thereby ruling out contamination at the farm.
"The results provided evidence to make a case of potential hazards,"
said Warriner. "RPCs used to ship food are a recipe for disaster. We
recommend that the decontamination method for RPCs be reviewed to
prevent carriage and transfer of human pathogens."
The results also show a significant variation in the sanitary status of
RPCs, and that many RPCs were damaged and visibly dirty. Visual
inspection of RPCs revealed a proportion that were damaged or had
labels affixed from previous use. While the root of this problem is
unknown, inefficient cleaning systems and travel to-and-fro wash
stations in the USA may explain the sanitary issues.
The study was commissioned following food safety concerns expressed by
the growers who are told to ship fruit and vegetables using RPCs,
rather than the traditional choice, corrugated boxes.
"We have heard anecdotal reports from growers that the RPCs delivered to
their farms sometimes arrive dirty," said André Plante, General
Manager, Quebec Produce Growers Association. "For the safety of
Canadians, we need to ensure all food in Canada is shipped using clean
packaging, regardless of whether it is paper or plastic."
Commenting on the use of RPCs over corrugated by some packers and
retailers, Mike Harwood, president and CEO of the World Containerboard
Organization said he "believes produce retailers like to showcase their
fruits and vegetables in corrugated packaging because boxes are a
natural product, made from renewable wood fibre and are totally
sustainable in our environment. Terrific retailers like Whole Foods,
Publix, and Costco, just to name a few, realize that beautifully
printed corrugated boxes also help them to sell more fresh produce to
About the Study
Keith Warriner, Professor of Food Safety at the University of Guelph,
assessed the microbiological standard of reusable plastic containers
used in different fresh produce packing stations. Locations in Ontario
and Quebec were visited during the course of the study. At each
location ten randomly selected RPCs were sampled.
A combination of ATP (adenosine triphosphate) swabs and microbiological
analysis were chosen to determine the sanitary status of RPCs. ATP
(adenosine triphosphate) readings taken at farms provided an estimate
of viable cells present on the surface of RPCs. The standards set were
those expected of a cleaned surface of a food contact surface within
the food industry with a 20% failure rate being deemed the upper limit
of acceptability. Trays were sampled as delivered thereby ruling out
contamination at the packing facility.
SOURCE: Canadian Corrugated Containerboard Association
For further information: