Guidelines for Cleaning, Disinfecting & Sterilization of Patient Care Equipment

• Introduction
• Definitions (general)
• Definition of Liquid Chemical
• Rational Approach to Disinfection and Sterilization
• "Classification of Devices, Processes and Germicidal Products" - Table
• "Low Level Disinfectants Listed for Non-Critical Items" - Table
• "Low Level Disinfectants Approved by Infection Control Committee" - Table
• Policies
• References

I. Introduction

These guidelines delineate methods to be used in the cleaning, disinfection, and sterilization of patient care equipment. These guidelines use the terminology used by the CDC’s "Guideline for Handwashing and Hospital Environmental Control, 1985" and the 1996 Association for Professional in Infection Control and Epidemiology (APIC) "Guideline for Selection and Use of Disinfectants", in which the levels of disinfection are defined as sterilization, high-level disinfection, intermediate-level disinfection, and low-level disinfection.

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II. Definitions (general)

1. Two Step and One Step Process for Disinfection (Back 2 Basics, Cleaning & Disinfection of Objects in the Patient's Zone)
   • Two Step Process is used for items that are visibly soiled or when there is a reasonably anticipated presence of blood or other potentially infectious materials, including Point of Care testing devices. This includes both a one step cleaning process and two step disinfection process.
   • One Step Process is used for items that are not visibly soiled or not reasonably anticipated that it would be soiled with blood or other potentially infectious materials.
2. Cleaning is the removal of all foreign material (e.g., soil, organic material) from objects. Failure to remove foreign matter (e.g., lubricants, soils) from an object before a disinfection or sterilization process is likely to render the process ineffective. There is no required contact/dwell/wet time for the cleaning process. It is normally accomplished as Step 1 for items that are visibly soiled or when there is a reasonably anticipated presence of blood or other potentially infectious materials, including Point of Care testing devices with mechanical action and:
   • water with detergents or enzymatic products
3. Disinfection describes a process that eliminates many or all pathogenic microorganisms, with the exception of bacteria spores, from inanimate objects. In the medical setting, this is generally accomplished by the use of liquid chemicals or wet pasteurization. This may be accomplished as a one step process for items that are not visibly soiled or not reasonably anticipated that it would be soiled with blood or other potentially infectious materials or the second part of the two Step process that starts with cleaning. The efficacy of disinfection is affected by a number of factors, each of which may nullify or limit the efficacy of the process. There is a required exposure time, the product remains wet for a specific duration of time, for each product. See Section V: “Low Level Disinfectants Approved by Infection Control Committee” – Table. Some of the factors that have been shown to affect disinfection efficacy are:
   • Previous cleaning of the object
   • Level of microbial contamination
   • The concentration of the germicide
   • The exposure (contact/dwell/wet) time to the germicide
   • The physical configuration of the object (e.g., crevices, hinges, lumens)
   • The temperature of the disinfection process
   • The pH of the disinfection process
4. Chemical disinfectants can be classified by several schemes:
   • High-level disinfection can be expected to destroy all microorganisms, with the exception of bacterial spores.
   • Intermediate-level disinfection inactivates Mycobacterium tuberculosis, vegetative bacteria, most viruses, and most fungi, but it does not kill bacterial spores.
   • Low-level disinfection can kill most bacteria, some viruses, and some fungi, but it cannot be relied on to kill resistant microorganisms such as tubercle bacilli or bacterial spores.
5. Sterilization is the complete elimination or destruction of all forms of microbial life. Either physical or chemical processes accomplish it. The term sterilization is intended to convey an absolute meaning, not a relative one. Principal sterilizing agents used in the medical setting are:
   • Steam under pressure
   • Dry heat
   • Low temperature sterilization processes (ethylene oxide gas [ETO] )
   • Plasma sterilization
   • Liquid chemicals

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III. Definition of Liquid Chemical

1. A germicide is an agent that destroys microorganisms, particularly pathogenic organisms ("germs"). Other agents designated by words with the suffix -cide (e.g., virucide, fungicide bactericide, sporicide, tuberculocide) destroy the microorganisms identified by the prefix.

   Germicides, including sterilants and disinfectants, are registered and regulated by the Environmental Protection agency (EPA).

2. A chemical sterilant is a chemical used for the purpose of destroying all forms of microbial life, including fungal and bacterial spores. These same chemicals may also be a part of the high-level disinfection process when used for shorter exposure periods.

3. A disinfectant is a germicide that inactivates virtually all recognized pathogenic microorganisms, but not necessarily all microbial forms (e.g., bacterial endospores) on inanimate objects.

4. An antiseptic is a chemical germicide formulated for use on skin and tissue and should not be used to decontaminate inanimate objects. Antiseptics are registered and regulated by the Food and Drug Administration (FDA).

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IV. Rational Approach to Disinfection and Sterilization

In 1968 a rational approach to disinfection and sterilization of patient care items or equipment was devised and published in Disinfection, sterilization and preservation by E. H. Spaulding. He believed that the nature of disinfection could be more readily understood if instruments and items for patient care were divided into three categories according to the degree of risk of infection involved in the use of the items.

Classification of Devices, Processes and Germicidal Products

 

Device Classification	Devices (examples)	Spaulding Process Classification	EPA Product Classification
Critical (enters sterile tissue vascular system)	Implants, scalpels, needles, other surgical instruments	Sterilization - sporicidal chemical; prolonged contact	Sterilant/disinfectant
Semicritical ( touches mucous membranes or skin that is not intact)	Flexible endoscopes, laryngoscopes, endotracheal tubes, and other similar instruments	High-level disinfectant - Sporcidal chemical; short contact	Sterilant/disinfectant
Noncritical (touches intact skin)	Stethoscopes, tabletops, bedpans, etc.	Low-level disinfection	Hospital approved disinfectant

1. Items that are assigned to the critical category present a high risk of infection if contaminated by a microorganism, including bacterial spores. It is critical that objects, which enter sterile tissue or the vascular system, be sterile. The category would include surgical instruments, cardiac and urinary catheters, implants, and needles. The majority of the items in this category should be purchased sterile or be sterilized by steam under pressure, if possible. If heat labile, the object may be treated with ETO or other low temperature sterilization processes categorized as chemical sterilants. These include 2% glutaraldehyde-based formulations, 6% stabilized hydrogen peroxide, peracetic acid. NOTE: Chemical sterilants can be relied on to produce sterility only if adequate cleaning precedes treatment and if proper guidelines with regard to organic load, contact time and temperature and pH are met.
2. Semi-critical items are those objects which come in contact with mucous membranes or skin that is not intact. These items must be free of all microorganisms with the exception of bacterial spores. Intact mucous membranes are generally resistant to infection by common bacterial spores but are susceptible to other organisms, such as tubercle bacilli and viruses. Respiratory therapy and anesthesia equipment, endoscopes and cervical diaphragm fitting rings are included in this category.

   Semi-critical items generally require high-level disinfection with wet pasteurization or chemical disinfectant. Glutaraldehyde, stabilized hydrogen peroxide, chlorine, and peracetic acid are dependable high-level disinfectants, provided the factors influencing germicidal procedure are considered (see table below). It is recommended that semi-critical items be rinsed with sterile water after disinfection. In circumstances under which a sterile water rinse is not feasible, a tap water rinse should be followed by an alcohol rinse and forced-air drying. The introduction of forced-air drying significantly reduces bacterial contamination of stored endoscopes, presumably by removing the wet environment favorable for bacterial growth.

   Some semi-critical items (e.g. hydrotherapy tanks, used for patients whose skin is not intact, thermometers) may require only intermediate-level disinfection. Intermediate-level disinfectants (e.g., chlorine, phenolics, iodophor) inactivate M. tuberculosis, vegetative bacteria, most viruses, and most fungi but can not be relied on to kill bacterial spores.

3. Non-critical items are those items that come in contact with intact skin but not mucous membranes. Intact skin acts as an effective barrier to most microorganisms, and sterility is not critical. Examples of non-critical items include bedpans, blood pressure cuffs, crutches, bed rails, linens, some food utensils, bedside tables and patient furniture. The low-level disinfectants listed for non-critical items in the table below may be used.

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Low-Level Disinfectants Listed for Non-Critical Items

Object	Sterilization		Disinfection
	Critical Items (will enter tissue or vascular system or blood will flow through them)		High-level (semicritical items [except dentala] will come in contact with mucous membrane or nonintact skin)	Intermediate-level (some semicritical itemsb and noncritical items)	Low-level (noncritical items; will come in contact with intact skin)
	Procedure	Exposure time (hr.)	Procedure (exposure time greater than or equal to 20 min.) c,d	Procedure (exposure time < to 10 min.	Procedure (exposure time < 10 min.)
Smooth hard surfaceb	A B C D E	MR MR MR 6 MR	C D E Ff G	Ge H J K	H I J K L
Rubber tubing and cathetersd	A B C D E	MR MR MR 6 MR	C D E Ff
Polyethylene tubing and cathetersd,g	A B C D E	MR MR MR 6 MR	C D E Ff
Lensed instruments	A B C D E	MR MR MR 6 MR	C D E>
Thermometers (oral and rectal)h Hinged instruments	A B C D E	MR MR MR 6 MR	C D E	Hh

1. Heat sterilization, including steam or hot air (see manufacturer’s recommendations).
2. Ethylene oxide gas (see manufacturer’s recommendations).
3. Glutaraldehyde-based formulations (2%). (Caution should be exercised with all glutaraldehyde formulations when further in-use dilution is anticipated).
4. Stabilized hydrogen peroxide 6% (will corrode copper, zinc and brass).
5. Peracetic acid, concentration variable but ≤less than or equal to 1% is sporicidal.
6. Wet pasteurization at 70^o C for 30 minutes after detergent cleaning.
7. Sodium hypochlorite (5.2% household bleach) 1:50 dilution (1000 ppm free chlorine).
8. Ethyl or isopropyl alcohol (70% to 90%).
9. Sodium hypochlorite (5.2% household bleach) 1:500 dilution (100 ppm free chlorine).
10. Phenolic germicidal detergent solution (follow product label for use-dilution).
11. Iodophor germicidal detergent solution (follow product label for use-dilution).
12. Quaternary ammonium germicidal detergent solution (follow product label for use-dilution).

MR, Manufacturer’s recommendations.
^a Semicritical dental items (e.g. handpieces, amalgam condensers) should be heat sterilized; refer to text for details.
^b See text for discussion of hydrotherapy.
^c The longer the exposure to a disinfectant, the more likely it is that all microorganisms will be eliminated. Ten minutes’ exposure is not adequate to disinfect many objects, especially those that are difficult to clean because they have narrow channels or other areas that can harbor organic material and bacteria. Twenty minutes’ exposure is the minimum time needed to reliably kill M. tuberculosis and nontuberculous mycobacteria with glutaraldehyde.
^d Tubing must be completely filled for chemical disinfection; care must be taken to avoid entrapment of air bubbles during immersion.
^e Used in laboratory where cultures or concentrated preparations or microorganisms have spilled. This solution may destroy some surfaces.
^f Pasteurization (washer disinfector) of respiratory therapy and anesthesia equipment is a recognized alternative to high-level disinfection. Some data challenge the efficacy of some pasteurization units (J Hosp Infect 1983;4:119-208).
^g Thermostability should be investigated when appropriate.
^h Do not mix rectal and oral thermometers at any stage of handling or processing.

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V. Infection Control Committee approved low-level disinfectants

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VI. Policies

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VII. References:

Bloodborne Pathogens Standard.

CDC and Healthcare Infection Control Practices Advisory Committee (HICPAC), Guidelines for Environmental Infection Control in Health-Care Facilities

Favero MX, Bond WW. Chemical Disinfection of Medical and Surgical Materials.
In: Block SS, ed. Disinfection, Sterilization, and Preservation. 4th ed. Philadelphia, Lea & Febiger, 1991; 617-641

Rutala WA. APIC Guidelines for Selection and Use of Disinfectants. American Journal of Infection Control. 1996; 24:313-342.

Spaulding EH. Chemical Disinfection of Medical and Surgical Material.
In: Block SS, eds. Disinfection, Sterilization, and Prevention. Philadelphia: Lea & Febiger, 1968; 517-531.