Are There Dangerous Germs Lurking in Your Kitchen?

By Lisa YakasMicrobiologist and manager of NSF International’s Home Product Certification Program A new study reveals the surprising places where germs and bacteria hide and why proper cleaning is essential.

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Over the past few years, there has been an increase in the number of Americans who prepare and cook food at home. While many turned to cooking at home as a cost-cutting measure during the Great Recession, for many it is a trend that is here to stay. In fact, a recent Harris Interactive Poll reveals that 71% of Americans are still cooking at home to save money.

Aside from the financial motivation, many Americans are cooking at home because they believe it is a healthier choice than eating out. Cooking in your own kitchen provides a sense of control – you know what ingredients are going into the meal you’re preparing. However, you may not know everything that is going into your next meal – and what you don’t know might actually hurt you and your family. 

Studies have shown that more than 20% of foodborne illness outbreaks result from food that was consumed in the home. NSF International food-safety experts point to a number of contributing factors, including improper food storage, handling and preparation.  

A global public health organization, NSF International has a long history in working to help ensure safe design and cleaning of equipment or appliances used in food preparation. NSF’s Commercial Food Equipment Program commenced in the 1940s, focusing on items 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 material and design, the program evaluates manufacturers’ cleaning instructions to help prevent equipment from harboring pathogens that can cause foodborne illness.  

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, Listeria, yeast and mold. All of these can potentially be harmful and especially dangerous to at-risk populations, including the elderly, pregnant women, children and those with compromised immune systems, resulting in anything from allergic reactions to diarrhea and abdominal pain to fever and even death in the most severe cases. 

The study found that some common kitchen appliances, utensils and tools are, in fact, contaminated with harmful bacteria and germs. All of the kitchenware tested revealed the presence of one or more of these microorganisms. Some of the “germiest” items that have the potential to cause illness included the refrigerator vegetable compartment, refrigerator meat compartment, blender gasket, can opener, rubber spatula, and food storage containers with rubber seals. Here are some things to consider before whipping up your next meal at home:

Perception does not match reality. As part of the study, NSF asked volunteers what they thought were the “germiest” items in the kitchen. Those families cited the microwave keypad, can opener and refrigerator meat compartment as the germiest items. However, testing revealed the refrigerator water dispenser, spatula and blender gasket actually contained the most germs. Many volunteers didn’t consider their blender a germy item, but in reality, it was the third germiest item in the kitchen. The refrigerator water dispenser didn’t make their list at all, but both the water and ice dispensers proved to be areas of concern for yeast and mold, which are a problem for those with allergies. People’s perceptions of what is dirty impacts their cleaning behavior, so be sure to add these kitchen items to your weekly list of places to clean.

Below is a comparison of what were perceived to be the germiest items in the kitchen versus the actual germiest items (ranked from highest to lowest in germ count):