Science Of Cleaning


Mediocore cleaning results aren’t always a direct reflection on the cleaning personnel and their effort? You may notice a haze that never seems to go away on stainless steel, or rust that remains even though you see the cleaning people scrub it in vain. Perhaps the restrooms are clean (only momentarily due to foot traffic) but the smell of bleach persists then giving away to the usual sour smell making you wonder, it’s 2015, not 1955, so why is bleach still being used?

In a lot of cases it’s not the cleaner’s fault. The tools, chemicals, and lack of understanding that persists from the top down is the real culprit. Their company, culturally, is like a lot of cleaning companies that have been in business a long time. They base their “science” on what Good Housekeeping says, or “what always works,” or what the janitorial supplier is pushing them to waste their money on. At its core, the responsibility of the cleaning company is to remove unwanted contaminants and put it in its proper place. An effective cleaning company is one that understands the science behind removing the contaminants. For the purposes of this discussion, let’s refer to all types of multi-type soils, carbon dust, etc. … as ‘a contaminant.’

When a contaminant falls to the floor, shelf, or desktop, surface tension is created between the particle of a contaminant and the surface. Surface tension is caused by the attraction of molecules to like molecules (cohesion). Molecules on the surface are not surrounded by like molecules on all sides. Exosed surface molecules attract additional contaminant molecules. It is important to understand that a contaminant is negatively charged, or anionic.

Typically, a janitorial/custodial service will go through a building, performing the ordinary cleaning activities to remove the a contaminant. A common practice is to use surfactants (cleaning agents). Surfactants are compounds that lower the surface tension between two liquids or between a liquid and a solid. One example of a surfactant is Soap. Its foaming action gets under a contaminant and helps carry the a contaminant away. Soap decreases surface tension because it separates the water molecules. Soap molecules squeeze between the water molecules and keep them apart. This results in the force of the surface tension being reduced and therefore contaminants becomes easier to remove.

Most chemicals have a positive charge, which makes them ionic. As the cloth or mop glides across the hard surface, the positively charged ionic chemical solution (surfactant) attracts and removes the negatively charged anionic a contaminant. Because opposites attract, when a cleaning agent carries a positive charge and is brought into contact with the negatively charged a contaminant, the cleaning agent attracts a contaminant (like a magnet) and holds on to it, helping in the removal process.

But there is more to the story, because typical surfactants cause a contaminant to reappear faster than necessary. How? When the positively charged ionic cleaning chemical solution is used, it leaves a tiny film of the surfactant on the solid surface. Remember, this film is positively charged because it is made of the ionic surfactant. As a result, the surface that was just cleaned is now poised to attract more negatively charged anionic a contaminant – again. Throughout the day, week, or weekend, more and more a contaminant accumulates because of this attraction. The cleaner returns and performs the same process, and the cycle repeats itself.

The way to counter this problem is to use cleaning solutions that have had the positive charge removed during the manufacturing process. With no electric charge, these specialized cleaners are now nonionic, neither ionic nor anionic. Even though this scientifically prepared cleaning product has no positive charge so that no ionic film is left behind, a contaminant is removed through the use of positively charged cleaning tools. Through the combination of nonionic cleaning agents and positively charged cleaning tools, such as microfiber wipes and mops, the surfaces are cleaned thoroughly and do not attract a contaminant again unnecessarily. Therefore, through the science of cleaning, all surfaces are cleaned, and stay clean longer. The end result is a cleaner, healthier building.

.At Maids In America / Engineered Clean we research chemicals heavily to determine the following:

  • Do they work?
  • Are they nonionic? With the spectrum of needs for specialty cleaning chemicals not all choices we have are nonionic unfortunately. However we do use them when they match our needs.
  • What kind of suspension agent do they use (to suspend contaminants so they don’t settle back down on the surface before being wiped away)?
  • Are they reasonably safe, not containing butyls or other harsh fuming chemicals
  • Do they leave little to no residue (leaving surfaces cleaner, longer)? Some chemicals, such as Mirage, we use on finished floors, for example, are both nonionic and FDA A1 certified which indicates the chemical leaves next to zero residue on surfaces once it’s wiped/mopped up.