Walk into any office in Dublin or the Short North at 7 PM and you will see what the cleaning crew was told to do. The desktops are wiped. The trash is out. The carpet has vacuum lines. The chair you are about to sit in and the phone you are about to pick up look exactly the way they looked at 5 PM, because nobody wrote them down.
In 2012 a team from San Diego State University and the University of Arizona decided to find out what actually lives in an office. Krissi Hewitt, Charles Gerba, Sheri Maxwell and Scott Kelley sampled 90 offices across New York, San Francisco and Tucson, five surfaces in each: the chair, the desk phone, the desktop, the computer mouse and the keyboard. They counted bacteria the old way, on culture plates, and the new way, by sequencing the ribosomal RNA in every swab. The paper ran in PLoS ONE.
Sequencing turned up more than 500 bacterial genera from 20 different divisions. Five hundred kinds of bacteria, in ordinary offices, on ordinary surfaces. And the two surfaces that carried the most were the chair and the phone.
What the study found
The abundance ranking is the part that should interest anyone who signs a cleaning contract. Chairs and phones sat at the top. Keyboards and mice sat lower. The desktop, the one surface every office cleaning scope in the country names, was not the problem surface.
The bacteria themselves were mostly human. The dominant genera were the ones that live on skin and in the nose, mouth and gut, which is what you would expect on a surface that hands, faces and trousers touch all day. The study also found offices used by men carried more bacteria than offices used by women, and that Tucson offices looked different from the two coastal cities, likely because of the desert outside the window. None of it reads as an outbreak. It reads as a census of who has been in the room.
That is the point worth taking. A surface does not need to be dangerous to be dirty, and a cleaning scope does not need to be negligent to be aimed at the wrong thing. It only needs to have been written by someone who never asked where the load sits.
Why the chair and the phone lose
Look at the two surfaces from the crew’s side of the cart. A desktop is flat, hard and empty at night. One pass with a cloth and it is done, and it looks done. A chair is fabric or mesh, curved, with arms that take the weight of two forearms for eight hours and a seat edge that takes the back of two legs. A phone is a handset that touches a cheek and a mouth twenty times a day, sitting on a keypad with a dozen recessed buttons. Neither one gets faster with practice, and neither one looks dirty when it is.
So the scope skips them, and the skipping is invisible. We wrote about the same pattern with shared keyboards in hot-desk offices and again with the break room faucet handle. Attention follows the checklist, the checklist follows what looks dirty, and the surfaces people actually touch with their bodies fall through the gap.
There is a second cost. When a chair arm does get wiped, it is usually with whatever cloth is in the cleaner’s hand, which twenty minutes earlier was in the restroom. A chair that is never named in the scope is never assigned a cloth, and a surface without its own cloth is not being cleaned so much as visited.
What this means for a Columbus office
Most commercial office cleaning agreements we read in Columbus price the job per square foot and describe it in a paragraph: empty trash, wipe desks, vacuum, clean restrooms, dust surfaces as needed. Chairs appear nowhere. Phones appear nowhere. The two surfaces the science ranks first are covered by the words “as needed,” which in practice means when someone complains, and nobody complains about a chair.
Fixing it is not expensive. It is four lines in the scope.
- Name the chair. Arms and the front edge of the seat, on every occupied workstation, weekly at minimum and nightly in shared or hot-desk areas. Mesh and fabric get a product rated for soft surfaces; hard arms get the same EPA-registered disinfectant as the rest of the room.
- Name the phone. Handset, both ends, and the keypad, nightly. Wiped, kept wet for the labeled contact time, wiped again.
- Assign the cloth. Color-coded microfiber, with a color that never enters a restroom. If the crew cannot tell you which color touches the phones, they are using one cloth for the building.
- Name the check. How does anyone know it happened? A supervisor’s initials say the crew was there. A reading says the surface changed.
How we check it
On a free ATP walkthrough of an office, the handset on the busiest desk and the arm of the most-used chair are two of the first surfaces we swab. ATP testing measures adenosine triphosphate, the energy molecule in every living cell, and reports it in relative light units in about fifteen seconds. It does not count germs and it does not prove disinfection. What it tells you is whether the cleaning step removed what skin and breath left behind, and cleaning is the step that has to succeed before any disinfectant can do its job.
A handset that reads high the morning after service was skipped, whatever the sign-off sheet says. That is not an accusation against the crew. It is a description of the scope they were handed. The number is yours whether you hire us or not, and the four lines above are yours to send to whoever cleans your building tonight.
The one-sentence version for your office manager
A peer-reviewed study of 90 offices found more than 500 kinds of bacteria, with the chair and the phone carrying the most, and our cleaning scope does not name either one. Send that, and ask which cloth touches the phones.
Frequently asked questions
Which office surfaces carry the most bacteria?
In the 2012 PLoS ONE study of 90 offices, chairs and desk phones carried the highest bacterial counts of the five surfaces sampled. Keyboards and mice carried less. Desktops sat in between. The two surfaces with the most bacteria are the two most office cleaning scopes never name.
Is 500 kinds of bacteria in an office dangerous?
Not by itself. The study found the office bacterial community was dominated by organisms that live on human skin and in the nose, mouth and gut. It is a map of who has been in the room, not an outbreak. The lesson is that wiping the desktop misses where the load actually sits.
What should an office cleaning scope say about chairs and phones?
Name them. Chair arms and the front edge of the seat, the phone handset and keypad, on a stated cadence, with an EPA-registered disinfectant kept wet for its labeled contact time and a dedicated microfiber cloth. If the scope only says wipe desks, the desk is the only thing that gets wiped.
Can ATP testing show whether a phone handset was cleaned?
Yes, as a cleaning check. ATP measures organic residue in relative light units, so a handset that reads high after the nightly service still carries what hands and mouths left on it. It does not count germs or prove disinfection. It tells you whether the cleaning step happened on that surface.
Every Columbus medical, dental, wellness, and commercial facility gets the same offer: a free 30-minute ATP walkthrough. We swab your highest-touch surfaces, on the spot, and hand you the readings. No obligation, no pitch required to see the number. Book your free ATP walkthrough or text (614) 758-SPAN.
Erik Kuusisto, Owner
Swiff & Span Cleaning Company
Sources
- Hewitt KM, Gerba CP, Maxwell SL, Kelley ST. Office Space Bacterial Abundance and Diversity in Three Metropolitan Areas. PLoS ONE. 2012;7(5):e37849. PMID 22666400.