The Workplace’s Dirtiest Surfaces

By  //  June 2, 2012

Healthy Workplace Project

According to a recent Kimberly-Clark Professional study of germs on office surfaces, break rooms and kitchens top the list, with sink and microwave door handles found to be the dirtiest surfaces of all.

For the workplace germ analysis, hygienists from Kimberly-Clark’s Healthy Workplace Project (HWP) collected nearly 5,000 individual swabs from a range of offices to measure ATP levels, which is the molecule that provides the energy in the cells of all living organisms and provides an indication of contamination by animal, vegetable, bacteria, yeast, and mold cells. Surfaces with an ATP reading of 300 or higher are considered to have a high risk for illness transmission, while surfaces with an ATP reading between 100 and 300 suggest room for improvement.

The study, which was carried out in consultation with Dr. Charles Gerba, a professor of microbiology at the University of Arizona, found that the following surfaces were most likely to have ATP levels of 300 or higher:

HWP hygienists collected nearly 5,000 individual swabs from a range of surfaces in a variety of offices.

1. Sink faucet handles in the break room. (75% of the time)
2. Microwave door handles. (48% of the time)
3. Computer keyboards. (27% of the time)
4. Refrigerator door handles. (26% of the time)
5. Water fountain buttons. (23% of the time)

“People assume that bathrooms have the most germs,” Dr. Gerba said. “A lot of studies have been done about the desktop work area, but the break room has been overlooked. Usually the break room is a germ transfer point in the workplace; people eat lunches there, they cough. More colds and flus are spread in break rooms when they touch surfaces and share space with other people.”

Dr. Gerba

Drawing an analogy between restaurants and the typical office break room, Gerba suggests, “You are dealing with an unregulated restaurant in a lot of ways. People with different hygiene habits are sharing the space with no regulation.”

The study also found that half of all computer mice and desk phones have ATP levels above 100 but less than 300 perhaps because people tend to take more responsibility for the cleanliness of their personal spaces. However, an ATP above 100 still suggests there is a need for more attention to the importance of good hygiene in the office.

“Any workplace that fails to use good hygiene practices on a daily basis can become a breeding ground for bacteria and viruses,” says Brad Reynolds, the North American platform leader of the HWP.  Dr. Gerba and Reynolds offer five tips to avoid spreading germs and staying healthy in the workplace (go to HWP website for report details and recommendations):

  • Wash and dry your hands upon arrival at work, after using the restroom, and before and after eating (it can reduce germs by 77%);

    Have hand sanitizer readily available and use it frequently on the job.
  • Use hand sanitizer before and after meetings and when leaving work at the end of the day;
  • Clean desk surface, keyboard, mouse, telephone, conference room tables, conference room phone, and water fountain buttons daily with disinfectant. Desks typically have 400 times more germs than toilet seats. Develop a habit of wiping desktops, keyboards, mice and phones at the beginning or end of every workday.
  • Wipe down the most-touched areas in a break room daily with disinfectant (sink handles, microwave handle, refrigerator handle, and countertops); and
  • Keep hand sanitizer in the break room to reinforce healthy hand hygiene behaviors