Cleaning and Disinfecting

Cleaning is the prevention or removal of unwanted matter—the first line of defense in protecting health. For example, everyone wants clean air, clean water, clean indoor/outdoor environments, clean hands, and a clean “bill of health”.

This discussion will focus on cleaning and disinfecting indoor surfaces.

Cleaning precedes disinfection since you can’t disinfect a dirty surface, and removing organic soil (soil that contains or supports microbial growth) is driving inspection and measurement of outcomes using ATP (adenosine triphosphate) meters that measure light emitted from organic soil remaining on surfaces. Rationale? If you can show removal of organics, you validate removal of germs or germ-food, leading to a more hygienic surface even before disinfecting.

Still, rather than focusing on inspection using ATP meters, which is like closing the barn door after the horse has escaped, it is first vital to focus on effective prevention or removal of organic soils.

In addition, cleaning should embrace prevention or removal of other soils such as dust, grit, heavy metals, and chemical pollutants.

Answering the following four questions will guide you on your cleaning journey:

  1. Are our systems preventing soil?
  2. Are we removing or just rearranging soil?
  3. Is our disinfection effective (or needed)?
  4. What is the Return on Investment (ROI) using a system?

Preventing Soil — First, have and maintain adequate 1) bi-level and 2) carpeted entry matting, which can trap gross soil and debris (bi-level) then dry/wipe shoe soles (carpet mat). The bi-level mat is first, followed by a nylon or synthetic fiber carpet mat with a nonslip waterproof backing. Select large enough mats to allow several steps across surfaces to enable removing mud, moisture, road dust, heavy metals, pesticide residues, and more. What is not tracked into buildings does not have to be removed later, and does not become airborne or ingested by young children.

Keep outside walkways clean to reduce dirt tracked in.

Use vacuum cleaners that remove and contain soils. Check the Carpet and Rug Institute (CRI) site for vacuum cleaners that meet standards for soil removal, indoor air quality, and carpet wear. The vacuum does not always need HEPA media, but the overall system should enable removal and retention of dust preventing it from being inhaled.

Also, consider banning facial tissue boxes as they emit tiny clouds of dust with each tissue dispensed.

Removing or Rearranging Dust — Dusters are aptly-named when they rearrange or spread dust rather than remove it.

A damp microfiber cloth or tool is an effective dust-removal tool, while some dusters spread more particles than they remove.

Vacuuming does the best job where practical, microfiber is next in effectiveness, and black ostrich feather dusters a distant third.

Effective Disinfection — Disinfect touch points such as desk tops, door knobs, faucet handles, cafeteria tables, switch plates, and phones.

Disinfect only clean surfaces, or you are wasting time and money, and endangering health. Small amounts of organic soil (e.g., more than 5 percent) inactivate EPA-registered chemical disinfectants, so, in general, clean first.

Follow EPA-mandated label instructions carefully, such as keeping the surface wet with the disinfectant for 5-10 minutes of “dwell” to enable kill claims, while ensuring proper ventilation, and wearing personal protection (e.g., gloves and goggles).

Non-chemical interventions such as dry steam vapor can be highly effective at treatment times of just a few seconds, but directions are important to follow.

UV and other methods also enable disinfecting when used as directed on pre-cleaned surfaces.

— This article is excerpted from the Healthy Facilities Handbook. You can download the entire handbook at

This article originally appeared in the School Planning & Management June 2018 issue of Spaces4Learning.