Eating at your desk? Disinfectant is in order

Desk areas have more germs than toilets

Employees might save some time during the workday by having lunch at their desks, but they could pay for it by making themselves sick. According to a study released by the University of Arizona, the typical office desktop has more germs per square inch than the average toilet seat.

"We don’t think twice about eating at our desks, even though the average desk has 100 times more bacteria than a kitchen table and 400 times more bacteria than the average toilet," says Charles Gerba, PhD, an environmental virologist with the University of Arizona. "Without cleaning, a small area on your desk or phone can sustain millions of bacteria that could potentially cause illness."

Talking dirty

The worst offender on the typical desk is the telephone, the Arizona team found. According to the study, the typical desktop had 20,961 germs per square inch. Phones have up to 25,127 germs per square inch; keyboards can contain 3,295 germs per square inch; and computer mice 1,676 per square inch. The average toilet seat, surprisingly, is more germ-free, averaging 49 germs per square inch.

"Desks are really bacteria cafeterias," says Gerba.

His study, funded by cleaning giant The Clorox Co. in Oakland, CA, examined typical office sites in locations across the country. Each office included cubicles, open spaces, and private offices. One common feature was that cleaning routines were often limited to vacuuming and emptying trash and cleaning bathrooms (hence the relative cleanliness of the toilet seats), with little or no attention to desks.

During the three-month study, one group of office workers at each location was asked to clean their desks with disinfecting wipes. The other group left theirs alone. Bacterial samples were taken several times a day from just about every surface, handle, and knob.

Employees could be saved sick time by merely keeping a disinfecting cleaner nearby. Gerba’s study showed that the desks that were cleaned daily with disinfecting cleaner saw a 99.9% decrease in germs. In work areas where cleaning wasn’t performed, bacteria levels increased 19%-31% every day.

Gerba says the study indicates benefits of companies paying for individual desk cleanings, or at least supplying employees with disinfecting cleaners and instruction on the benefits of using them — and cold and flu season is a good time to start. "When someone is infected with a cold or flu bug, the surfaces they touch during the day become germ transfer points because some cold and flu viruses can survive on surfaces for up to 72 hours," Gerba points out.

Cleaning up desk spaces doesn’t appear to be a common habit among office workers, according to the Washington, DC-based Soap and Detergent Association (SDA), which conducts periodic surveys about cleaning habits. According to the SDA, 46% of Americans surveyed said they do not clean their desks before eating there; women are more likely to clean their desks before eating than are men.

So how can you help the people you work with lessen the likelihood that their desks will make them sick? The SDA offers theses suggestions:

  • Consider providing each of your employees (or each floor or section) with personal cleaning supplies such as wipes, sprays, and disinfectants to keep their personal environments clean and healthy.
  • Post signs encouraging frequent hand washing. A 2001 SDA survey found nearly three-quarters of offices and customer service facilities do not post signs reminding their employees to wash their hands.
  • Send an officewide e-mail encouraging hygienic activities at work and at home, to help prevent sickness for themselves and others.
  • Always ensure restrooms and kitchen areas are supplied with enough and proper cleaning products for hands and surfaces, including disinfectants and multisurface cleaners.

For more information, contact:

  • Charles Peter Gerba, PhD, Professor of Microbiology, University of Arizona. Phone: (520) 621-6906. E-mail:
  • The Soap and Detergent Association, 1500 K St. N.W., Suite 300, Washington, DC 20005. Web: