Cleaning & Maintenance Management Online

Restroom contamination study

September 19, 2010
From time to time, we are asked about the real cleanliness of restrooms.

Even if they look “clean” are they really clean?

To explore this issue, we implemented a performance measurement system over a 60-day period to examine hard data to compare facility appearance versus health goals.

Test criteria
An important element of the measurement system process utilized bio-waste testing in a cross section of client restrooms.

The test measures the amount of an organic compound (creatinine) found in human-excreted urine on floors near urinals and toilets.

The sampling was conducted in office facilities, universities and an airport.

The sampling schedule was randomized throughout the day to understand how a customer might experience the condition of the restroom, whenever they might use it.

Restrooms were first inspected for the attributes that were customer-defined and most commonly expressed as a complaint.

Once the physical inspection was completed, bio-waste testing was conducted in several locations within the restroom.

The results of both actions were tabulated and compared.

Gathering the data
Creatinine concentrations are expressed in units of milligrams (mg) per deciliter (dL).

The associated creatinine-connected bacteria count also indicates the aerobic bacteria left on the surface tested.

Measurements of 5 mg per dL or less indicate low levels of contamination and effective cleaning for health; levels of 6 mg per dL to 33 mg dL might be considered moderate contamination, needing attention and reasonable response; and finally, levels over 34 mg per dL indicate a high level of contamination, which might suggest more urgent improvement and continued tracking.

In our study, we found that about 5 percent of the restrooms tested exhibited creatinine concentration levels of 50 mg per dL or higher.

Roughly translated, that means about one in 20 public restrooms might merit more frequent attention and/or further testing.

Next, we examined the relationship between appearance and bio-waste contamination.

In this study, cleanliness appearance ranged between a low of about 74 percent to a high of about 96 percent defect-free environment.

Correspondently, creatinine concentration levels ranged from a low of zero to a high of 100.

Perhaps most interestingly, there was not a high degree of connection between how “clean” a restroom looked and the level of contamination found.

Indeed, no restroom inspected was judged to be dramatically “dirty.”

In some cases, where an odor was present, contamination levels were not materially different from areas where no odor was detected.

Our conclusion is that a restroom that looks “clean” may (or may not) have a high level of creatinine concentration.

In short, appearances can be deceiving.

An effective cleaning program creates both an acceptable appearance of cleanliness and low levels of bio contamination.

Medium or higher levels of urine and associated bacteria can indicate the need to evaluate and improve the restroom cleaning procedures — a key process improvement mandate.

What could be going on where high contamination levels are found?

Our experience has shown us that process failures might include: Poor staff training; ineffective chemicals; inadequate equipment; insufficient chemical dwell time; too long between cleaning frequencies; or just plain lack of control of the cleaning system.

Other observations
While the findings from this study are valid, an important lesson taken from the study is that the measurement protocol (creatinine concentration) is a very limited tool.

While accurate for sampling urine contamination, it fails to detect a variety of protein-based contamination.

The more comprehensive testing strategy measures adenosine triphosphate (ATP), which is the universal energy molecule found in all animal, plant, bacterial, yeast and mold cells.

The system provides information on the level of contamination for a broader set of contaminates.

The drawback with ATP testing is the cost of reliable equipment, which can range from $1,000 to $4,000 per unit.

Nonetheless, this testing model can be used beyond restrooms and can provide relatively accurate contamination readings in kitchens, dining areas, elevators, and even offices in an environment where monitoring cleaning for health is a priority.

Given these advantages, I suggest that future studies use an ATP strategy.


Vincent F. Elliott is the founder, president and CEO of Elliott Affiliates, Ltd. of Hunt Valley, MD, www.ealtd.com. He is widely recognized as the leading authority in the design and utilization of best practice performance-driven techniques for janitorial outsourcing and ongoing management.