How Clean Are High-Touch Surfaces?

“Looks Clean” vs. “Is Clean”: Surface Imaging to Evaluate Cleaning Effectiveness

At one time, if building managers were asked to evaluate the cleaning provided in their facilities, the response would typically focus on the appearance of the facility. For instance, we might hear, “The building looks nice and clean every day.”


However, there is one thing the professional cleaning industry has learned over the years, along with many building managers, and that is “looks clean” has little to do with “is clean.”


By this we mean, a facility certainly may appear well maintained, but a closer inspection may indicate microbial contamination on surfaces throughout the building. Depending on what kinds of pathogens are present, touching these surfaces could result in cross-contamination and illness.


This may not be the fault of the cleaning professionals servicing a facility since they are only able to work with the knowledge available. The fact is, however, we know much more about pathogens, germs, and bacteria today than in the past, and along with new surface imaging technologies that help locate these microorganisms, building managers and cleaning professionals are able to keep facilities cleaner and healthier than ever before.


So how do we begin the process of locating pathogens in a facility that could potentially harm human health? We conduct what is called a “surface vulnerability assessment.” The first step is to select high-touch surfaces in a facility for examination.


These could include the following:


• Light switches, door handles, and elevator buttons. These “high-touch” surfaces are frequently home to several infectious pathogens.

• Handles on refrigerators, microwaves, cabinets, coffee makers (as well as their controls), and coffee pots. If these items are contaminated, and are touched before consuming food, the possibility for cross-contamination becomes very high.

• Computers, phones, and touch screens. When used by several people, these can become very contaminated during the day. Making matters worse, they are often shared and not cleaned as effectively or as frequently as they should be.


With surfaces selected, our next step is to conduct tests to see if these areas are contaminated. In the past few years, technologies such as ATP (adenosine triphosphate bioluminescence) have been used to perform these tests. While ATP is still used and can prove useful, new surface imaging technologies provide much more information and take surface assessments to a much higher level.


For instance, surface imaging technologies can help do the following:

• Capture macroscopic surface images and generate contamination “density maps”. These maps enable managers and cleaning professionals to see more precisely what’s happening on a surface and help determine which cleaning procedures and products are best suited to remove these pathogens.

• Provide “spatially specific” contamination data, further helping managers and cleaning professionals pinpoint issues and training opportunities. With this information, professionals can evaluate existing cleaning protocols and determine what procedures are necessary to keep these surfaces healthy.


With these steps taken, managers and cleaning professionals have a much clearer picture of the health of their facilities; where problem areas exist; where cleaning protocols need to be changed or reevaluated; and whether those new steps are proving effective. Now when building managers are asked to evaluate the cleaning in their facilities, they have the data they need to determine if a surface truly is clean.


For more information on seeing your way to better cleaning, see and send us a message at, or call 1-833-SOLVE-00.

1 Comment
  • Posted at 10:19 pm, September 28, 2019

    Presence of microbes is not the only source of risk. Chemical residues can also be harmful. Removal of microbes through better cleaning and not necessarily disinfecting with a chemical agent is important. Also, one wonders if OS detects dead microbes or just living ones? UV lights kill microbes but do not remove them. Will OS see them?

Post a Comment