In previous posts we have reviewed the difference between “clean” and hygienic (see here and here). In this post I wanted to delve deeper into the choices of disinfectants for manual cleaning. We describe cleaning by hand as manual cleaning as it requires physical intervention in order to reduce bacterial contamination from the surface.
The CDC’s Healthcare Infection Prevention Advisory Committee (HICPAC) define cleaning as “removal of foreign material (e.g., soil, and organic material) from objects” (1) and it is recommended that cleaning take place prior to disinfection to remove organic material.
What disinfectant to use? There is a wide range of disinfectants available with a range of pros and cons as shown in the Table below. The Department of Health NY has published a terrific overview of the activity of a wide range of disinfectant agents, as well as cost which is below and taken from their website see 
here.
| Disinfectant Agent (loading levels) | Positives | Negatives | CDC Disinfection Level (1) |
| Alcohols (50-70%) | Rapidly evaporates with no residue, useful for medical device sterilization. | Low in sporicidal activity.
Flammable. |
INTERMEDIATE |
| Bleaches-chlorine containing and sodium hypochlorite (4-6%) | High activity against a broad spectrum of organisms and very rapid activity. | Can lose available chlorine over time-should be used within 3 months.
Corrosive and damaging to some materials. Inactivated by organic material. |
INTERMEDIATE |
| Hydrogen Peroxide (<3%) | Limited efficacy spectrum | Corrosive and damaging to some materials..
Can be strong irritant. |
LOW |
| Iodophors (0.5-5%) | High activity, short contact time.
Not affected by water hardness |
Can cause stains and odors. | INTERMEDIATE |
| Quaternary Ammonium Compounds “Quats” (2%) | Can be formulated to both clean and disinfect when combined with detergent.
Odorless |
Low in sporicidal, fungicidal and mold activity. Affected by water hardness, organic material and even plastics. | LOW |
| Phenolic Compounds (0.2-3%) | Eliminates fecal contamination | Corrosive and damaging to some materials.
Can be strong irritant. |
LOW/ INTERMEDIATE |
Equally important as the selection of disinfecting agent is the selection of areas to be cleaned. What areas are to be cleaned? There are a range of guidelines from Federal (OSHA, CDC) and State or recommendations from bodies (APIC/AHE) that should be followed. In today’s post we are going to look at just the environmental surfaces (hard and soft) in the patient environment. For more information please review the full guidelines contained in (1).
The best breakdown of patient surfaces in terms of importance for disinfection was a study conducted 30 years ago by Earle H. Spaulding who devised a rational approach to disinfection and sterilization of patient-care items and equipment (2). The system is a three tiered system as outlined below;
CRITICAL
Critical items enter sterile tissue or the vascular system. Examples include surgical instruments, cardiac or urinary catheters, implants, ultrasound probes that are used in sterile body cavities.
Disinfection options-purchased sterile or sterilized with steam, ethylene oxide, or a liquid germicide, glutaraldehyde-based formulations either alone or with phenol/phenate, stabilized hydrogen peroxide, either alone or with peracetic acid.
SEMICRITICAL
These items contact mucous membranes or nonintact skin. Examples include endoscopes and other medical devices as well as hydrotherapy tanks or bed side rails. These devices should be free from all microorganisms but some bacterial spores are permissible.
There have been some updates from the FDA (3) around endoscopes due to ECRP linked outbreaks of CRE (more information here).
Disinfection options-A liquid germicide, glutaraldehyde-based formulations either alone or with phenol/phenate, stabilized hydrogen peroxide, either alone or with peracetic acid for a contact time to achieve a 6-log10 kill of an appropriate Mycobacterium species for medical devices., and an INTERMEDIATE DISINFECTANT from the table above for the bed rails and other items.
NONCRITICAL
Contact intact skin but not mucous membranes. These category is further divided into patient care items and environmental surfaces. The thought is that the intact skin will protect the patient and therefore sterility is “not critical”.
Examples of patient care items-blood pressure cuff, bedpans, and computers.
Examples of environmental surfaces-bed rails, bedside tables, floors, patient furniture.
Disinfection options-Low level disinfectants with 10 minute claims from the EPA disinfectant registered products lists, and all options from the table shown above.
How often should these surfaces be cleaned/disinfected?
In addition to what to use, and where to disinfectant, how often should surfaces be cleaned? Just to follow up our earlier point cleaning means “removal of foreign material (e.g., soil, and organic material) from objects”, whilst disinfection is the removal of pathogenic organisms from the environmental surface. HICPAC guidelines indicate that housekeeping surfaces (e.g., floors, tabletops) should be cleaned on a regular basis, when spills occur, and when these surfaces are visibly soiled. Environmental surfaces should be disinfected on a regular basis (e.g., daily, three times per week) and when surfaces are visibly soiled. Other items in the patient rooms such as walls, blinds, and window curtains should be cleaned when visibly contaminated or soiled.
I hope this overview of disinfectants, where to clean and how often is helpful. In future posts we will be reviewing how effective cleaning or disinfection is and the variety of options for touchless disinfection and alternate technologies such as copper surfaces that we have not touched upon in this article. As always feel free to add your comments or thoughts to this post below!
References quoted in this post
- CDC, HICPAC, Guideline for Disinfection and Sterilization in Healthcare Facilities, 2008
- Spaulding EH. Chemical disinfection of medical and surgical materials. In: Lawrence C, Block SS, eds. Disinfection, sterilization, and preservation. Philadelphia: Lea & Febiger, 1968:517-31
- May 14-15, 2015 meeting of the Gastroenterology-Urology Devices Panel of the Medical Devices Advisory Committee
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