There are two basic principals in all cleaning; pH and physical removal. 

Physical removal is one of the best microbial decontamination processes. It lessens the numbers of pathogens from all surfaces as well as removes the food sources that aide in their growth. If contaminates are removed from a surface, it is no longer possible for them to effect the immediate area, thus accomplishing the task. 

Physically removing contaminates (bacteria and soil) from surfaces, should be the goal of any cleaning procedure. 

In order to physically remove contaminates from a surface, it is often necessary to alter their chemical state. This is the pH principle of cleaning. 

The pH principle of cleaning starts with water. Pure water has a pH of 7. For bacteria to be killed or for many common soils to be removed, their pH needs to be changed. Adding chemical compounds to water which may or may not alter the pH, can aide in the physical removal process. Depending on the surface, the type of soils present and the required results, using a solution with the correct pH and chemical make-up for the task at hand, can make the cleaning process effective.

Technicians who are focused on green cleaning must be educated in these two principals. Knowing how to balance these two principals when performing daily tasks, will have great impacts on not only the frontline technician, but the occupants of the facility. Balancing physical removal from equipment or tools with the pH strength of the cleaning solution, will also produce better end results.. After all, green cleaning is about not only protecting the health of individuals, but additionally valuable surfaces within the built environment.

David Thompson is a 40-year veteran of the cleaning industry and author of “The New Generation of Cleaning”, a best Practices Guide for Environmental Health Services. Thompson is also president of the Green Clean Institute. His book can be found at while the GCI coursework and certification courses have a home at