The holy grail for housekeeping managers is an objective, measurable method of determining cleanliness. It is critical to improving the professional management of facility cleaning. But what is clean? The answers are various and immeasurable across the industry — it looks clean, feels clean or smells clean based on each individual’s interpretation. This subjective evaluation plagues an industry intent on providing proof of quality services to building occupants and facility executives.

What housekeeping decision makers are looking for is a number they can use — a criterion that can be universal.

There is a bacteria culture test used in hospital cleaning which measures bacteria growth to determine the effectiveness of disinfection procedures on a given surface. However, these tests take days to evaluate, and then the results reflect past effectiveness or lack of effectiveness. The cleaning industry requires more immediate results to facilitate evaluation.

Another existing method, used to measure floor surfaces, might be the answer housekeeping decision makers have been looking for. Currently, the Americans with Disabilities Act (ADA) requires a coefficient of friction (COF) reading to verify safety requirements in public facilities.

The coefficient of friction is the quotient obtained by dividing the value of the force necessary to move one body over another at a constant speed by the weight of the moving body. For example, if a force of 20 newtons is needed to move a body weighing 100 newtons over another horizontal body at a constant speed, the coefficient of friction between these two materials is 20/100 or 0.2. Different materials in contact yield different results. Therefore, a different coefficient of friction must be calculated for each different pair of materials.

The ADA requirements call for a COF reading of 0.6 on level surfaces and 0.8 on ramps. There are digital machines available that can test the COF quickly and accurately, providing an instant readout.

Case in point
Rick Foate of Dominion Restoration Products recently made the connection between COF readings and measurements of cleanliness when he was trying to find conclusive evidence that one of his cleaning products was effective at cleaning grouted tile floors. He decided to attempt to restore the tile to the original state measured at the time it was manufactured. How to measure this accomplishment presented a dilemma, but he knew that the quarry tile he was cleaning was tested at the time of manufacture for a coefficient of friction to meet ADA requirements.

The COF on that particular quarry tile at the time of manufacture was 0.75 wet. Foate contacted a national quick-service restaurant that had the same quarry tile and asked for an opportunity to test and clean their floor.

The restaurant first cleaned the floor with a company-approved cleaning agent before the COF test was conducted. Foate used a digital Universal Walkway Tester obtained from the National Floor Safety Institute to test the tile’s COF. The floor looked clean, but tests showed a reading of 0.47 when the tile was wet. This indicated that a film had been left on the tile, causing a reduction in the COF of the floor, despite cleaning with the restaurant’s approved chemicals.

Foate then cleaned the floor with his product and tested the floor again, resulting in a 0.75 wet COF and proving the cleaning ability of his product.

Foate’s test and others like it illustrate that using coefficient of friction readings to determine the cleanliness of quarry tile could provide the industry with a potential tool to consistently measure service levels against an existing standard — the COF at time of manufacture. This means nothing is left on the surface tested, so it truly must be clean.

Scope of implication
The same methodology can be applied to ceramic tiles, porcelain tiles and all other tiles tested for COF during manufacturing. Housekeeping managers simply must determine a baseline COF after installation that matches the manufacturer’s results. Then they can gauge the effectiveness of any cleaner or cleaning procedure through post-cleaning COF testing.

The potential even may extend to other hard floor surfaces. Consider taking COF readings on newly laid floor finish to determine a baseline for the cleanliness of the finish, as well as validating ADA requirements. Then contractors can take readings after cleaning, spray buffing or burnishing to see their effects on the baseline COF.

Documentation of methods and chemicals resulting in appropriate COF readings can establish a basis for procedures and a means of measuring effective application during quality checks. If regular COF readings are taken, a drop in results may indicate a procedural error or the need for recoating. Replacing unreliable visual evaluations with measurable data would facilitate better training, management and quality control.

Estimated costs to purchase a Universal Walkway Tester are about $4,000, which some managers may balk at. But regular use in multiple buildings such as a university or large office complex would quickly recoup the cost because it would result in more efficient cleaning methods and controlled chemical use.

If this method of testing cleanliness catches on, the alternative to purchasing a machine is to encourage a distributor to have several machines that could be rented or provided as a regular service for a nominal fee. After all, there are implications for distributors testing COF to show end users how a product should work during proper use.

Because the Universal Walkway Tester also works on carpet and mats, the machine could be useful for cleaning standards on those surfaces as well. What if a baseline COF for new carpet can be measured, and housekeeping managers could discover if soiling would impact the reading? If possible, the COF would be a measurable criteria for clean carpets as well as hard floors.

More testing of COF measurements with carpeting, flooring, cleaners, finishes and procedures needs to be done to determine the procedure’s scope of use for cleaning operations, but the initial findings are very encouraging, and the possible impact on the industry could be great. Imagine: no more uncertainty regarding cleanliness, or regarding the ability to determine effective cleaning procedures and set performance standards.

A medical professional would never determine if a broken bone had healed by sight, feel or smell but would rely on proven tests such as x-rays. Cleaning professionals equally should rely on measurable tests to determine cleanliness. To that end, the industry should be encouraging increased use of measurable tests and the development of testing technology. Perhaps COF readings aren’t the only existing test that housekeeping managers can utilize to determine levels of clean. The only way to know is to experiment. Taking such chances only can lead the industry closer to much needed solutions.

Steve Spencer is cleaning and interior maintenance senior specialist for State Farm Insurance. He also will host an operations improvements seminar for cleaning service providers at the ISSA/INTERCLEAN Show, Oct. 16 in Las Vegas.




POSTED ON: 8/1/2002