NSF International has a long history of working to help ensure safe design and cleaning of equipment and appliances used in food preparation. NSF’s Commercial Foodservice Equipment Program began in the 1940s, focusing on equipment used in restaurants. More recently, NSF’s Home Products Certification Program was created, establishing test protocols for many kitchen appliances and tools designed specifically for home use.

Because of NSF’s role in evaluating the cleanability of common kitchen tools and appliances used in the home, the NSF microbiologists conducting the 2013 NSF International 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 common kitchen appliances and tools used to prepare food do indeed harbor pathogens that cause foodborne illness. It’s our hope that the information gained from this study will further underscore the importance of properly maintaining and cleaning these items.

The six “germiest” items contained the following microorganisms that can cause sickness:

  1. Refrigerator vegetable compartment: Salmonella, Listeria, yeast and mold
  2. Refrigerator meat compartment: Salmonella, E.coli, yeast and mold
  3. Blender gasket: Salmonella, E. coli, yeast and mold
  4. Can opener: Salmonella, E. coli, yeast and mold
  5. Rubber spatula: E. coli, yeast and mold
  6. Food storage container with rubber seal: Salmonella, yeast and mold

Highlights from the analysis include:

  • E. coli36 percent of items contained E. coli. Items with E. coli included the refrigerator meat compartment, rubber spatula, blender gasket, can opener and pizza cutter.
  • Salmonella36 percent of items had Salmonella including the refrigerator vegetable and meat compartments, can opener, blender gasket and the rubber seal on a food storage container.
  • Yeast and moldAll 14 items (100 percent) tested positive for yeast and mold, and six items (43 percent) tested positive at concerning levels. The six items with concerning levels of yeast and mold were the refrigerator vegetable compartment, rubber spatula, blender gasket, refrigerator ice and water dispensers, and the rubber seal on a food storage container.
  • Listeria14 percent of items tested positive for Listeria. The refrigerator vegetable compartment contained Listeria, as did the refrigerator door seal.

Are We Unknowingly Making Ourselves and Others Sick?

These germs were found on everyday kitchen appliances and tools that come in direct contact with food, especially raw produce, meat, poultry, seafood and ready-to-eat food. Importantly, while volunteers correctly identified items that they thought would harbor the most germs, they are not always cleaning them thoroughly to prevent illness.