A reader writes: “In your workshop, you described four levels of clean. I am still confused since the word “clean” can have many different meanings. Could you elaborate?”

I apologize for not being clearer discussing this very important subject. Cleaning can mean different things to different people in different industries. Following is a brief overview of what we discussed and my approach to the subject. I am sure that there are those who will vehemently disagree and that is why we have open discussions.

“Clean” is to take a cloth and dust/clean a surface. There is no kill rate since the intent is to physically remove visible dust/debris, not kill germs.
“Sanitize” is to use a chemical sanitizer or disinfectant, as per label directions, to kill and remove a quantity of microorganisms (think germs, viruses, bacteria). Mark Warner of Cleaning Management Institute says true sanitization kills 99.999 percent of the organisms. Others state that it is up to 99 percent. I will defer to the experts in this discussion.
“Disinfect” is to use an EPA-registered product correctly (think dwell time, staying wet, etc.) to kill (according to Mark Warner) 99.9999999 percent of the microorganisms on the surface. Others may disagree and claim other kill rates.
“Sterilization” means to kills 100 percent of the microorganisms on the surface by means of heat. This process is usually limited to doctors/dentists using an autoclave (think pressure cooker) to accomplish this task. For all practical purposes, we should not use the term sterilize for day-to-day cleaning/disinfection of surfaces such as counter tops, floors, etc.

Just remember that any product used incorrectly can be ineffective. Also remember that the most hostile environment for a microorganism is a clean, dry surface exposed to light and air. No food; no life.

Please understand that the above descriptions are mine and certainly not the only approach that others may take. Continue to do your research and come to your own conclusions.