Environmental Cleaning, Sanitizing and Disinfecting During Covid-19 Part II

Organizations need to start the discussion from a multi-disciplinary team approach to include (at least) Environmental Services, Infection Prevention, Surgical Department leaders, Purchasing, and the Safety Officer. A consensus needs to be achieved on what the meaning of cleaning is, what sanitizing is and what disinfecting is.


Cleaning - the physical removal of foreign material, e.g., dust, soil, organic material such as blood, secretions, excretions, and microorganisms. Cleaning generally removes rather than kills microorganisms. It is accomplished with water, detergents, and mechanical action. The terms “decontamination” and “sanitation” may be used for this process in certain settings, e.g., central service or dietetics. Cleaning reduces or eliminates the reservoirs of potential pathogenic organisms.

Sanitation: a process that reduces microorganisms on an inanimate object to a level below that of infectious hazard (e.g., dishes and eating utensils are sanitized).

Disinfection: the inactivation of disease-producing microorganisms. Disinfection does not destroy bacterial spores. Disinfectants are used on inanimate objects in contrast to antiseptics, which are used on living tissue. Disinfection usually involves chemicals, heat, or ultraviolet light. The nature of chemical disinfection varies with the type of product used. Cleaning and Sanitizing is a process where 99.9% of all organisms are removed from the surface. Cleaning and Sanitizing IS NOT Disinfecting. Cleaning is a physical removal of bioburden from surfaces. Sanitizing is applying low level disinfectants to a surface to minimally reduce organisms. Disinfection is a process where EPA approved germicidal agents are applied to surfaces that result in at least a 99.99% destruction of organisms. This 0.01% is a significant factor that must be understood and taken into consideration. If colony forming units (CFU) remain on surfaces – biofilm can develop which presents the opportunity for cross-contamination.

Many scientists and epidemiologists support the notion that surfaces do not play an integral role in the transmission of organisms that result in a patient infection. However, many of these same people support the studies that show surfaces are contaminated and do contain organisms that are identified through surface testing measures. The question facing healthcare organizations is: If surfaces do not play a role in the transmission of infections to patients – why do we need to disinfect them at all?

Usually disinfectants are "cidal" in that they kill the susceptible potential pathogenic agents. The selection of a disinfectant should be based on the function the disinfectant is expected to perform, not necessarily on a sales pitch or on what you have always used. Ideally, a disinfectant should be broad spectrum (eliminates bacteria, viruses, protozoa, fungi, and spores), nonirritating, nontoxic, and noncorrosive. Selection decisions should include effectiveness against the potential pathogenic agent, safety to people, impact on equipment, and the environment. Disinfectant effectiveness depends on many factors.

Each disinfectant has specific properties and chemical mixtures to work against specific pathogens. No single disinfectant is effective against all pathogens. For a disinfectant to qualify as ‘hospital grade’ it must be tested against only two (2) organisms: Pseudomonas aeruginosa and Staphylococcus aureus.

There are currently 14 different lists that the EPA maintains with approved disinfectants for a variety of different pathogens and classifications. Each of these lists contain different products with different chemical formulas. The important aspect for healthcare organizations to know from the manufacturers is: What is the ‘mode of action’ or what particular agent/process kills pathogens. The following is a breakdown of the different types of chemicals used as disinfectants:

In these chemical compounds there exist different chemicals and chemical reactions that destroy pathogens. The important part to understand is what drives the ‘contact time’ that is recommended from the manufacturer.

Pathogen destroying chemical reactions include:
• Action on the external membrane of the bacterial wall
• Action on the bacterial wall
• Action on the cytoplasmic membrane
• Action on energy metabolism
• Action on the cytoplasm and nucleus
• Action on bacterial spores

Aspergillus mold is a very common mold that is found indoors and outdoors all around the world. So, how did this very common mold get inside of hospitals and cause several child deaths? The obvious answer would be the air intake systems, but more than likely it was transferred from outdoors to indoors via shoes, clothing, boxes, or shipping materials. Many studies show that pathogens remain on environmental surfaces after the cleaning and disinfection process. Isolates such as MRSA, VRE, C-diff, Aspergillus, Pseudomonas, and other pathogens remain in large colony forming units (biofilm) for days after disinfection has occurred. The question healthcare organizations must answer is: Why?

If healthcare organizations are going to continue to consider environmental surfaces a noncritical component of the patient care environment, cross contamination will continue. Today, we need to think differently about our environment, internal surfaces, high touch/frequently touched surfaces, and other components of the physical structure. We do not need to become germaphobes, but we do need to become germ conscious. We need to define what surfaces will be sanitized versus disinfected. We need to define if we are going to clean and disinfect in two separate steps or attempt to do them simultaneously. We need to ensure that the walls, floors, ventilation system, furniture, light switches, plants, and other pieces of physical environment are cleaned/disinfected on a routine or even daily basis.

We know that floor studies have shown pathogens to remain on the floor surface after mopping, which can then be kicked up into air currents as people walk by/through a space. Do we need to clean, sanitize, or disinfect our floors? Can we sanitize or disinfect our floors without creating a sticky surface or destroying the floor materials? The answer is yes to all the above, it is simply a matter of making the decision to do so. Floors can be sanitized with steam or can be disinfected with neutral disinfectants.

We want to offer the following recommendations around cleaning/disinfecting processes and selecting the proper product for the task:

• Identify/List what surfaces are to be cleaned, sanitized, or disinfected.
• Define a ‘goal’ or identify what is trying to be achieved for each of the identified surfaces.
• Select a product that meets the ‘goal’ of what is trying to be achieved – cleaner, sanitizer or disinfectant.
• Utilize the selection criteria above to determine mode of action, contact time and safety component.
• Test the products in predetermined locations for ease of use, mixing and effectiveness.
• Do not allow ‘cost’ to be the sole determinant of product choice.

Remember, cleaning and disinfecting are separate processes according to the CDC, AORN and APIC. Cleaners remove bioburden and Disinfectants destroy organisms. Different chemicals kill different organisms at different times. The first step to preventing cross contamination is to remove organic material from a surface, then apply disinfectants to kill any remaining pathogens. This is the best approach to providing a clean physical environment for your patients and visitors. Please choose wisely, patients deserve a clean and safe environment when they are being cared for.

1) How long do nosocomial pathogens persist on inanimate surfaces? A systematic review.
Axel Kramer; PubMed 2006: https://pubmed.ncbi.nlm.nih.gov/16914034/
2) Guideline for Disinfection and Sterilization in Healthcare Facilities (US CDC -2008)
3) A Guide to Selection and Use of Disinfectants (BC CDC - 2003)
4) Selected EPA-Registered Disinfectants. https://www.epa.gov/pesticide-registration/selected-epa-registered-disinfectants
5) Targeted Moments of Environmental Disinfection (TMED) – Diversey. https://cleaningbytheprofessionals.co.uk/targeted-moments-environmental-disinfection-knowlex

For additional information on this topic, go to The Courtemanche & Associates Quality Academy and select Managing the Physical Environment During the Covid-19 World Crisis for an on-demand presentation.

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