The 6 Dirtiest Places in Your Office

Where Office Germs Lurk in Break Rooms, on Desks

Medically Reviewed by Laura J. Martin, MD on May 22, 2012

May 22, 2012 -- What's by far the dirtiest place in the typical office?

It's the sink faucet handles in the break room, according to a down-and-dirty study by Kimberly-Clark Professional. They offer a program to "help companies provide their employees with a healthier and more productive office environment."

The study researchers swabbed some 4,800 surfaces in office buildings housing some 3,000 employees. Office types included manufacturing facilities, law firms, insurance companies, health care companies, and call centers.

The swabs were run through a device that measures ATP, the energy molecule found in all animal, plant, bacteria, yeast, and mold cells. Food residues -- or residues of "other organic materials" -- contain large amounts of ATP, according to the device maker.

When the device reads 100 or more, the surface could stand to be cleaned. When the device reads 300 or more, the surface is officially dirty and in need of a good cleaning. The device does not specifically detect germs, although dirty surfaces do provide a breeding ground for bacteria.

The study got the "officially dirty" readings of 300 or more on:

  • 75% of break room sink-faucet handles
  • 48% of microwave door handles
  • 27% of keyboards
  • 26% of refrigerator door handles
  • 23% of water fountain buttons
  • 21% of vending machine buttons

Overall, the study got "could-be-cleaner" readings of over 100 on:

  • 91% of break room sink-faucet handles
  • 80% of microwave door handles
  • 69% of keyboards
  • 69% of refrigerator door handles
  • 53% of water fountain buttons
  • 51% of computer mice
  • 51% of desk phones
  • 48% of coffee pots and dispensers
  • 43% of vending machine buttons

Charles Gerba, PhD, the University of Arizona professor known as "Dr. Germ" because of his highly publicized studies finding that common surfaces are crawling with bacteria, served as a consultant on the Kimberly-Clark study.

"People are aware of the risk of germs in the restroom, but areas like break rooms have not received the same degree of attention," Gerba says in a news release. "This study demonstrates that contamination can be spread throughout the workplace when office workers heat up lunch, make coffee, or simply type on their keyboards."