Skip to main content

College Germ Study

NSF scientists tested the homes of college-aged students looking for the presence of major germ groups.

Imagine the typical college student’s home — dirty dishes in the sink, molding food left spoiling on the counters or forgotten in the fridge, and mildew growing in the shower. Often living on their own for the first time, these students, age 18-25, admit they don’t clean very often. As a result, they are at risk of being exposed to the sort of pathogens that could keep them out of the classroom.

NSF scientists tested the homes of college-aged students in the southeast Michigan area, looking for the presence of four major germ groups:

  • E. coli Associated with food poisoning, this bacteria can cause vomiting, fever and in rare cases death.
  • Coliforms: These bacterial colonies can harbor disease-causing pathogens of fecal origin.
  • MRSA: Methicillin-resistant Staphylococcus aureus causes infections and resists antibiotics.
  • Yeast and mold: These can cause respiratory disease or magnify allergies.

Top germiest items

The top six “germiest” items contained these microorganisms that can cause illness (listed with highest percentage first):

  1. Dish sponge: Coliforms, yeast, mold, E. coli
  2. Shower/tub drain: Coliforms, E. coli
  3. Kitchen sink drain: Coliforms, yeast, mold, E. coli
  4. Shower head: Yeast, mold
  5. Kitchen faucet handle: Mold, yeast, coliforms, E. coli
  6. Coffee maker: Mold, yeast, coliforms, E. coli

Perception versus reality

College students who volunteered to have their homes tested were also surveyed to discover what they thought the germiest areas might be. The student volunteers earned what could be considered a “D” in the classroom, identifying only 60 percent of the germiest items in their homes. Some of the items or areas they thought would be the germiest, including high-touch surfaces of their cell phones, computer keyboard, microwave oven handle, TV remote control and bathroom doorknobs, did not make the list. They also failed to identify the potential for germ growth in their coffee maker.

Are we unknowingly making ourselves and others sick?

Getting sick is no way to experience college, and the students’ own homes may threaten their health. Students with compromised immune systems from diseases such as diabetes, asthma or the flu can become ill from these germs. Students can also have depressed immune systems due to lack of sleep or poor diet, which may weaken their resistance and cause them to get sick. This could mean missed classes or poor performance in school, adding unnecessary stress.

Good cleaning habits help students make the grade

Students can improve their cleaning grade to an “A” by following a few simple cleaning tips, paying extra attention to wet, textured surfaces that may hide germs. NSF conducted similar studies in 2011 and 2013 and found household areas and items like the dish sponge, sink drain and faucet handle were the perfect environment for germs.

Dish sponge: Microwave for two minutes once per day and replace every week or two.

Kitchen sink: Apply disinfecting cleaner to the sink sides and bottom one or twice a week.

Faucet handles: Clean daily with disinfecting cleaner or disinfecting wipes.

Shower drain: Disinfect with a bathroom cleaner at least once a week.

Coffee maker: Clean with soap and hot water after every use. Once a week, run the machine with equal parts water and white vinegar or cleaning solution.

How NSF Can Help You

Get in touch to find out how we can help you and your business thrive.

What’s New with NSF

  • iNADO Partners with NSF to Support Members and Athletes

    May 27, 2026
    iNADO is pleased to welcome NSF’s expertise and experience in support of its members and the athletes they serve
    Read the Story
  • NSF Ends UK’s Three-Year Testing Gap with REG 31 Testing Designation

    May 20, 2026
    NSF’s Oakdale laboratory becomes the UK’s sole facility offering comprehensive BS 6920 and REG 31 testing, closing a critical drinking water safety gap.
    Read the Story
  • Tangent® Materials Announces Industry First: Tangent PolySheet™ CB Earns Certification to NSF 537, Becoming the First PFAS-Free NSF Standard 51 Food Equipment Material

    May 20, 2026
    New food-grade synthetic cutting-board sheet, engineered from the ground up without per- and polyfluoroalkyl substances (PFAS), establishes a new materialsafety benchmark for food-contact and food-equipment applications.
    Read the Story
  • NSF Expands Food Equipment Portfolio with Electrical Safety Testing and Certification

    April 30, 2026
    Manufacturers now have a “one-stop-shop” for both sanitation and electrical safety certification, enabling market expansion and regulatory compliance.
    Read the Story