NSF International offers tips on proper cleaning and care of home appliances and kitchen items

ANN ARBOR, Mich. — NSF International’s Applied Research Center (ARC), which conducts original research and development projects for academia, industry, and regulatory bodies to further public health and safety, has released the 2013 NSF International Household Germ Study, revealing that many common kitchen items harbor unsafe levels of E. coli, Salmonella, Listeria, yeast and mold.

Scientists at NSF International, a global public health and safety organization, point to a number of contributing factors, including improper food storage, handling, preparation and cleaning, which may help explain why more than 20 percent of foodborne illness outbreaks result from food consumed in the home.*

The NSF microbiologists conducting the germ study analyzed 14 common kitchen items for the presence of four different types of microorganisms:  E. coli, Salmonella, yeast and mold, and Listeria. The study found that many of these common kitchen appliances and tools used to prepare food do indeed harbor pathogens that can cause foodborne illness:

  • Refrigerator vegetable compartment: Salmonella, Listeria, yeast and mold
  • Refrigerator meat compartment: Salmonella, E. coli, yeast and mold
  • Blender gasket: Salmonella, E. coli, yeast and mold
  • Can opener: Salmonella, E. coli, yeast and mold
  • Rubber spatula: E. coli, yeast and mold
  • Food storage container with rubber seal: Salmonella, yeast and mold

It is NSF’s hope that the information gained from this study will further underscore the importance of properly maintaining and cleaning these items, especially those that we don’t always think to disassemble and clean such as the blender gasket.

“Consumers are increasingly concerned about the safety and quality of their food but often don’t realize that they may be the cause of foodborne illness in their own homes, due to improper cleaning of kitchenware and appliances. As a NSF microbiologist, I was surprised to learn that most people know what items carry germs, but they still didn’t clean them properly. Products that come in direct contact with food must be designed and maintained properly to prevent germ growth. The performance, quality, material safety and cleanability of home products all are important for food safety,” said Rob Donofrio, Ph.D., Director of NSF International’s Applied Research Center.

"Young children, the elderly and those with weakened immune systems are particularly vulnerable to foodborne illness," said Dr. Donofrio. "Concerned consumers can look for the NSF Home Product Certification mark on products to ensure items can be cleaned correctly when following the manufacturer’s instructions to prevent harboring germs."

Perception vs. Reality:  Are We Unknowingly Making Ourselves and Others Sick?

Importantly, while germ study volunteers correctly identified items that they thought would harbor the most germs, they are not always cleaning them sufficiently to prevent illness. The following is a list of the items that were perceived by volunteers to be the “germiest” versus the actual “germiest” items (ranked from highest to lowest in germ count):

Perceived:

  1. Microwave keypad
  2. Can opener
  3. Refrigerator meat compartment
  4. Refrigerator vegetable compartment
  5. Flatware storage tray
  6. Knife block
  7. Pizza cutter
  8. Rubber spatula
  9. Refrigerator insulating seal
  10. Ice dispenser 

Reality:

  1. Refrigerator water dispenser
  2. Rubber spatula
  3. Blender
  4. 4. Refrigerator vegetable compartment
  5. Refrigerator ice dispenser
  6. Refrigerator meat compartment
  7. Knife block
  8. Food storage container with rubber seal
  9. Can opener
  10. Refrigerator insulating seal

Germs found on these everyday kitchen appliances and tools can easily come in direct contact with food, especially raw produce, meat, poultry, seafood and ready-to-eat food. The study identified where the germs are located in the average home kitchen and, more importantly, how people can better protect against foodborne illness. The key is to be aware of where the ‘hot spots’ are in your home and clean correctly and regularly to help prevent germ accumulation.

"What's important to remember is the science behind the study. Germs exist everywhere and while not all germs are 'bad,' our goal is to educate the public about how they can help keep their families healthy," said Dr. Donofrio.

For more information on NSF International’s Applied Research Center, visit: www.nsf.org/info/ARC.

For tips on how to keep kitchen appliances and tools clean, please visit the NSF's 2013 Germ Study webpage.

Media Contact: To schedule an interview with a NSF expert, contact Greta Houlahan at houlahan@nsf.org or 734-913-5723.

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Household Germ Study Methodology: The NSF International 2013 Household Germ Study was conducted by microbiologists at NSF International’s Applied Research Center in Ann Arbor, Mich., from July to October 2012, with results published in March 2013. Swab kits, which included a swab for each of the 14 kitchen items to be analyzed, were provided to 20 volunteer families throughout the Ann Arbor area. The scientific testing swab was saturated with a sterile medium with a neutralizer that helps pick up germs from surfaces. Volunteers were instructed to wear gloves and rub the wet swab tip in a turning motion across a designated surface area of each of the 14 items. They then placed the swab with the sample back into the swab container without touching the tip to anything else to ensure an accurate sample. These samples were then analyzed by NSF microbiologists for the presence of microorganisms such as E. coli, yeast and mold, Salmonella and Listeria species.

About NSF International: NSF International is a global independent public health and safety organization that helps protect consumers by certifying products and writing standards for food, water, dietary supplements and consumer goods to minimize adverse health effects and protect the environment. NSF International’s Applied Research Center (ARC) provides original research and custom R&D services for the water, food, pharma, consumer products and sustainability industries. ARC establishes strategic partnerships with academia, industry and regulatory bodies for research and development projects geared to furthering public health.

The NSF Consumer Products Division builds on NSF International’s expertise in national standards and protocol development, testing and certification to help ensure the safety, performance and quality of consumer products and appliances used in and around the home. NSF has worked to help ensure the safe design and cleaning of food equipment and appliances used in food preparation since the 1940s, focusing on equipment used in restaurants. NSF’s Home Product Certification Program began in 2012, addressing kitchen appliances and tools used in the home.  In addition to evaluating performance, durability and materials, the program evaluates manufacturers’ cleaning instructions to help prevent equipment from harboring pathogens that can cause foodborne illness.

* Source: Centers for Disease, Control and Prevention: Tracking and Reporting Food Disease Outbreaks, http://www.cdc.gov/features/dsfoodborneoutbreaks/