A SAFE ENVIRONMENT: CLEANING, DISINFECTING, AND STERILIZING

The healthcare environment can easily become contaminated with pathogens. The potential for contamination exists in every area of the hospital or other healthcare facility. Contaminated patient-care equipment (e.g., wet or soiled dressings), invasive devices that were used in diagnosis and treatment (e.g., surgical instruments or endoscopes), and environmental surfaces (e.g., doorknobs, floors, toilets) can act as vehicles for the transmission of infection to healthcare workers and/or patients. In addition, contamination depends on:

• The potential for external contamination (e.g., presence of hinges, crevices)
• The potential for internal contamination (e.g., presence of lumens)
• The physical composition, design, or configuration of an instrument, medical device, equipment, or environmental surface

General Environmental Surface Cleaning

Transmission of infections to either staff or patients is largely via hand contact with a surface. Thus, cleaning and disinfecting environmental surfaces is fundamental to reducing the incidence of HAIs.

The number and type of pathogens present on environmental surfaces are affected by:

• Number of people in the environment
• Amount of activity
• Amount of moisture
• Presence of material able to support microbial growth
• Rate at which organisms suspected in the air are removed
• Type of surface and orientation (horizontal or vertical)

Cleaning is the first step of any sterilization or disinfection process and requires the physical action of scrubbing with detergents and surfactants and rinsing with water.

Cleaning is followed by disinfection. The following are factors that influence the choice of disinfection procedure for environmental surfaces:

• The nature of the item to be disinfected
• The number of microorganisms present
• The innate resistance of those microorganisms to the inactivating effects of a germicide
• The amount of organic soil present
• The type and concentration of germicide used
• The duration and temperature of germicide contact

Environmental surfaces can be divided into medical equipment surfaces (e.g., knobs or handles on equipment) and housekeeping surfaces (e.g., floors, walls, and tabletops).

Manufacturers of medical equipment provide care and maintenance instructions specific to their equipment. These instructions include information about:

• The equipment’s compatibility with chemical germicides
• Whether the equipment is water-resistant or can be safely immersed for cleaning
• How the equipment should be decontaminated if servicing is required

Use barrier protective coverings as appropriate for equipment surfaces that are:

• Touched frequently with gloved hands during the delivery of patient care
• Likely to become contaminated with blood or body substances
• Difficult to clean (e.g., computer keyboards)

Most, if not all, housekeeping surfaces (e.g., floors, walls, tabletops) must be cleaned on a regular basis using only soap and water or a detergent/disinfectant, depending on the nature, type, and degree of contamination. Spills must be cleaned up promptly. Walls, blinds, and window curtains in patient-care areas are cleaned when visibly dusty or soiled.

High-touch housekeeping surfaces in patient-care areas (e.g., doorknobs, bed rails, light switches, wall areas around the toilet in the patient’s room, and the edges of privacy curtains) are cleaned and/or disinfected more frequently than surfaces with minimal hand contact.

Disinfectant/detergent formulations registered by the Environmental Protection Agency (EPA) are used for environmental surface cleaning, but the most important step is the physical removal of microorganisms and soil by scrubbing and/or wiping.

A one-step process and an EPA-registered hospital disinfectant/detergent designed for general housekeeping purposes should be used in patient-care areas when:

• The nature of the soil on these surfaces is uncertain
• The presence or absence of multidrug-resistant organisms on such surfaces is uncertain

Follow facility policies and procedures for effective handling and use of mops, cloths, and solutions (ADA, 2022; CDC, 2023c, 2023e).

Cleaning Immunosuppressed-Patient Areas

In areas where immunosuppressed patients are cared for, cleaning/disinfecting involves:

• Wet dusting of horizontal surfaces daily with cleaning cloths premoistened with detergent or an EPA-registered hospital detergent/disinfectant
• Avoiding the use of cleaning equipment or methods that disperse dust or produce mists or aerosol
• Equipping vacuums with HEPA filters
• Regular cleaning and maintenance of equipment to ensure efficient particle removal
• Closing the doors of immunocompromised patients’ rooms when vacuuming, waxing, or buffing corridor floors to minimize exposure to airborne dust
  (CDC, 2023e)

Cleaning Up Blood Spills

All environmental and working surfaces must be promptly cleaned and decontaminated after contact with blood or OPIM. Protective gloves and other appropriate PPE should be worn, and an appropriate disinfectant should be used.

After putting on personal protective equipment:

• If the spill contains large amounts of blood or body fluids, clean the visible matter with disposable absorbent material, and discard in an appropriate, labeled container.
• Swab the area with a cloth or paper towels moderately wetted with disinfectant and allow the surface to dry.
• Use EPA-registered hospital disinfectants labeled tuberculocidal or registered germicides with specific label claims for HIV or HBV.
• Use an EPA-registered sodium hypochlorite product; if not available, general versions (e.g., household chlorine bleach) may be used.
• Use a 1:100 solution of hypochlorite product or chlorine bleach to decontaminate nonporous surfaces after cleaning a spill in patient-care settings.
  (CDC, 2023e)

Reprocessing Healthcare Equipment and Devices

Depending on the intended use, reusable medical and surgical equipment and devices must undergo reprocessing that involves:

• Cleaning alone, for noncritical items
• Cleaning followed by disinfection, for semicritical items
• Cleaning followed by sterilization, for critical items

REPROCESSING EQUIPMENT/DEVICES

Classification/Intended Use	Goal of Process	Appropriate Process
(CDC, 2023e; Cumming, 2020; JST Medical, 2023)
Noncritical items Objects that come into contact with intact skin but not mucous membranes, and high-touch surfaces, e.g.: BP cuffs Tabletops Bedpans Stethoscopes IV poles Commodes Crutches Computers	Clean of: Soil Blood Protein substances Other debris Cleaning and disinfection with compatible materials	Cleaning (manual or mechanical) Low-level disinfection Responsibility of cleaning and clinical staff
Semicritical items Items that make contact, directly or indirectly, with intact mucous membranes or nonintact skin, e.g.: Endoscopes Anesthesia equipment Respiratory therapy equipment	Free of all microorganisms, with exception of high numbers of bacterial spores	High-level disinfection (thermal, chemical)
Critical items Items entering sterile tissue, body cavity, vascular system, nonintact mucous membranes, e.g., surgical instruments	Free of all microorganisms, including bacterial spores	Steam sterilization Low-temperature sterilization If liquid chemical sterilization is used, the item is to be used immediately

CLEANING

Cleaning involves removal of foreign material (e.g., soil, organic material) from objects and is normally accomplished using water with detergents or enzymatic products. Thorough cleaning is required before high-level disinfection and sterilization because inorganic and organic material remaining on the surfaces of instruments interfere with the effectiveness of these processes. If soiled materials dry or bake onto the instruments, the removal process becomes more difficult and the disinfection or sterilization process less effective or ineffective.

Perform either manual cleaning (using friction) or mechanical cleaning (using ultrasonic cleaners, washer-disinfector, or washer-sterilizer).

When a washer-disinfector is used, care should be taken in loading instruments: hinged instruments should be opened fully to allow adequate contact with the detergent solution; stacking of instruments in washers should be avoided; and instruments should be disassembled as much as possible.

There are no real-time tests that can be used in a clinical setting to verify cleaning. The only way to ensure adequate cleaning is to conduct a reprocessing verification test (e.g., microbiologic sampling), but this is not routinely recommended (Cumming, 2020; Potter et al., 2023).

DISINFECTION

Disinfection describes a process that eliminates many or all pathogenic microorganisms (except bacterial spores) on inanimate objects. In healthcare settings, objects usually are disinfected by liquid chemicals or wet pasteurization. Factors that can affect the effectiveness of either method include:

• Organic and inorganic load present
• Type and level of microbial contamination
• Concentrations of an exposure time to the germicide
• Physical nature of the object
• Presence of biofilm
• Temperature and pH of the disinfection process
• Relative humidity of the sterilization process

There are three levels of disinfection, as described in the table below.

LEVELS OF DISINFECTION

Level	Disinfection/Process
(Cumming, 2020)
Low	Ethyl or isopropyl alcohol Sodium hypochlorite Phenolic germicidal detergent solution Iodophor germicidal detergent solution Quaternary ammonium germicidal detergent solution
Intermediate	Ethyl or isopropyl alcohol Sodium hypochlorite Phenolic germicidal solution Iodophor germicidal detergent solution
High	Glutaraldehyde-based formulation Ortho-phthalaldehyde Hydrogen peroxide Hydrogen peroxide and peracetic acid Wet pasteurization at 70 °C for 30 minutes with detergent cleaning Hypochlorite

STERILIZATION

Sterilization destroys all microorganisms on the surface of an article or in a fluid to prevent disease transmission. Medical devices that have contact with sterile body tissues or fluids must be sterile when used. The use of inadequately sterilized items represents a high risk of transmitting pathogens; however, documented transmission of pathogens associated with an inadequately sterilized critical item is exceedingly rare.

FDA-approved sterilization methods are described in the table below.

STERILIZATION METHODS

Sterilization Process	Description	Uses
(Dias et al., 2023; Potter et al., 2023)
Steam under pressure (moist heat)	Uses four parameters: steam, pressure, temperature, time Most widely used Most dependable Can corrode some materials	Heat-stable medical and surgical devices
Flash steam	Modification of conventional steam sterilization where item is placed on an open tray or in a container for rapid penetration of steam	Cleaned patient-care items that cannot be packaged, sterilized, and stored before use When there is insufficient time to sterilize an item by preferred method Not recommended for implantable devices
Low-temperature ethylene oxide (ETO) gas	Parameters: Gas concentration Temperature Relative humidity Exposure time	Temperature- and moisture-sensitive medical devices and supplies
Hydrogen peroxide gas plasma	Inactivates microorganisms by the combined use of hydrogen peroxide gas and the generation of free radicals	High temperature– and humidity-intolerant materials and devices, including: Some plastics Electrical devices Corrosion-susceptible metal alloys
Peracetic acid	Chemical sterilant Biocidal oxidizer Effective in presence of organic soil	Medical and surgical instruments (e.g., endoscopes, arthroscopes)
Dry heat	Static or forced air penetrates material	Materials damaged by moist heat or impenetrable to moist heat (e.g., powders, sharp instruments, petroleum products)

MONITORING REPROCESSING EFFECTIVENESS

Effectiveness of reprocessing depends on:

• Thorough cleaning before either disinfection or sterilization
• Choice of the right disinfectant product
• Presence of organic matter (inadequate cleaning), which can inactivate many disinfectants
• Use of mechanical scrubbing. In general, biofilms are not readily removed by chemicals alone but require mechanical scrubbing. (Biofilms are constructed by some bacteria to protect themselves from hostile environments such as disinfectants. An example of a biofilm is the film on teeth in the morning, not removed by mouthwash, requiring brushing.)

Monitoring disinfection is essential to document the effectiveness of reprocessing. Factors to be documented include:

• Activity (concentration) of the disinfectant
• Contact time with internal and external components
• Recordkeeping and tracking of equipment usage and reprocessing
• Handling and storage after disinfection to prevent contamination

Monitoring sterilization involves maintaining records of each sterilizer load, routinely evaluating the sterilizing conditions, and indirectly evaluating the microbiologic status of the processed items. This is accomplished by using a combination of mechanical, chemical, and biological indicators.

• Mechanical monitors for both steam sterilization and ETO sterilization provide data on cycle time, temperature, and pressure. However, two essential elements for ETO sterilization (gas and humidity) cannot be monitored in healthcare ETO sterilizers.
• Chemical indicators are affixed on the outside of each pack to indicate that the item has been exposed to the sterilization process. They do not, however, prove sterilization has been achieved. A chemical indicator should also be placed on the inside of each pack to verify sterilant penetration. Chemical indicators are either heat- or chemical-sensitive inks that change color when one or more sterilization parameters are present. Chemical indicators should be used in conjunction with biological indicators.
• Biological indicators are considered to be the closest to ideal because they measure the sterilization process directly by using a preparation of the most resistant pathogen (Bacillus spores) as an indicator of sterility. These preparations are added to a carrier and then packaged. Biological indicators specifically designed for monitoring flash sterilization are now available, and a new rapid-readout ETO biological indicator has been designed for rapid and reliable monitoring of the process.

Periodic infection control rounds to areas using sterilizers for the purpose of standardizing use may identify correctable variances in operator competence, documentation of sterilization records, sterilizer maintenance and wrapping, and load numbering of packs (Schrubbe, 2020).

PACKAGING, STORAGE, AND HANDLING OF PROCESSED ITEMS

Written and illustrated procedures for preparation of items to be packaged should be readily available and used by personnel when packing procedures are performed. Sterility standards should follow the manufacturer’s recommendations (e.g., a maximum relative humidity in the storage area of 60% and a temperature of no more than 72–78 °F [22–26 °C]).

Once items are cleaned, dried, and inspected, those requiring sterilization must be wrapped or placed in rigid containers and arranged in instrument trays/baskets according to guidelines.

There are several choices in packaging methods to maintain sterility of surgical instruments, including:

• Rigid containers
• Peel-open pouches, (e.g., self-sealed or heat-sealed plastic and paper pouches)
• Roll stock or reels (i.e., paper-plastic combinations of tubing designed to allow the user to cut and seal the ends to form a pouch)
• Sterilization wraps (woven and nonwoven)

The packing material must:

• Allow penetration of the sterilant
• Provide protection against contamination during handling
• Provide an effective barrier to microbial penetration
• Maintain the sterility of the processed item after sterilization

Packages are inspected to ensure sterility. If they do not pass, they are returned for correction and reprocessing.

Wrapped surgical trays remain sterile for varying periods depending on the type of material used to wrap the trays. Safe storage times for sterile packs vary with the porosity of the wrapper and storage conditions. The central surgical area where sterile supplies are stored must be free from excess humidity, heat, cold, dirt, dust, moisture, and contamination. Sterile supplies can be stored with nonsterile supplies but must be clearly labeled.

Any sterilized item should not be used after the expiration date has been exceeded or if the sterilized package is wet, torn, or punctured. This practice recognizes that the product should remain sterile until some event causes it to become contaminated (e.g., tear in packaging, packaging becomes wet, or seal is broken).

Following the sterilization process, handling of medical and surgical devices must use aseptic technique in order to prevent contamination.

Any healthcare facility must be able to show evidence of a written policy that demonstrates knowledge of evidence-based guidelines and national standards (TJC, 2022).

REPROCESSING AND REUSE OF SINGLE-USE DEVICES

Reusing single-use medical devices (SUDs) has been occurring since the late 1970s. Single-use medical devices can be reprocessed within healthcare organizations or by outside vendors (third-party reprocessors). Specifically, the FDA requires third-party reprocessors to meet the same criteria for the reprocessed devices as the original equipment manufacturer.

The public health risk presented by a reprocessed SUD varies. Some that are low risk when used only one time may present an increased risk to a patient upon reprocessing. Others that are low risk when used for the first time may remain low risk after reprocessing, provided the reprocessor conducts cleaning and sterilization/disinfection in the appropriate manner.

WHEN DISINFECTION/STERILIZATION IS PERFORMED ELSEWHERE

According to the NYS Department of Health, those health professionals who practice in settings where handling, cleaning, and reprocessing equipment, instruments, or medical devices are performed elsewhere (such as a dedicated Sterile Processing Department) should:

1. Understand core concepts and principles, including:
   1. Standard/Universal Precautions (e.g., wearing of PPE)
   2. Cleaning, disinfection, and sterilization (see above)
   3. Safe practices for handling instruments, medical devices, and equipment in the area of professional practice
   4. Physical separation of patient-care areas from cleaning and reprocessing areas
2. Verify with those responsible for reprocessing what steps are necessary prior to submission:
   1. Precleaning
   2. Soaking

New York healthcare professionals who have primary or supervisory responsibilities for equipment, instrument, or medical device reprocessing (such as Sterile Processing Department staff or clinics and physician practices where medical equipment is reprocessed on-site) should:

1. Understand the core concepts and principals identified in #1 above
2. Determine appropriate reprocessing practices, taking into consideration:
   1. Selection of appropriate methods:
      1. Antimicrobial efficacy
      2. Time constraints and requirements for various methods
      3. Compatibility among equipment and material
         1. Corrosiveness
         2. Penetrability
         3. Leaching
         4. Disintegration
         5. Heat tolerance
         6. Moisture sensitivity
      4. Toxicity
         1. Occupational health risks
         2. Environmental hazards
         3. Abatement methods
         4. Monitoring exposures
         5. Potential for patient toxicity/allergy
      5. Residual effect
         1. Antibacterial residue
         2. Potential for patient toxicity/allergy
      6. Ease of use
         1. Need for specialized equipment
         2. Special training requirements
      7. Stability
         1. Concentration
         2. Potency
         3. Efficacy of use
         4. Effect of organic material
      8. Odor
      9. Cost
      10. Monitoring
          1. Frequency
          2. FDA regulations for reprocessing single use devices
(NYSDOH, 2018)

Waste Management

Treatment of regulated medical waste reduces the microbial load in or on the waste and renders the byproducts safe for further handling and disposal. Prior to 1997 and a change in the Environmental Protection Agency (EPA) standards, 90% of all medical waste was incinerated. Regulated medical waste treatment methods now include:

• Chemical disinfection
• Grinding/shredding/disinfection methods
• Energy-based technologies (e.g., microwave, radio-wave treatments)
• Disinfection/encapsulation methods

Medical wastes require careful disposal and containment. Occupational Safety and Health Administration (OSHA) requirements are designed to protect workers who generate medical waste and who manage the wastes from point of generation to disposal. Personnel responsible for waste management must receive appropriate training in handling and disposal methods in accordance with facility policy.

State medical waste regulations specify appropriate treatment for each category of regulated waste. Major categories of medical waste requiring special handling and disposal precautions include:

• Microbiology laboratory wastes (e.g., cultures and stocks of microorganisms)
• Bulk blood, blood products, blood, and bloody body fluid specimens
• Pathology and anatomy waste
• Sharps (e.g., needles, broken glass, and scalpels) that can transmit disease (e.g., human immunodeficiency virus, hepatitis C)

NEW YORK STATE REGULATED MEDICAL WASTE (RMW)

New York State provides regulatory oversight of regulated medical waste. It has adopted a comprehensive regulatory framework covering all aspects of handling, storage, treatment, and disposal of this waste, and has stated its expectations with respect to differing levels of disinfection and sterilization methods and agents based on the area of professional practice, setting, and scope of responsibilities.

In accordance with these laws and regulations, both the New York State Department of Health (DOH) and the Department of Environmental Conservation (DEC) jointly administer New York State’s RMW program.

The DEC has oversight authority for all storage, treatment, and destruction processes located onsite of facilities not under DOH jurisdiction; for off-site transport of RMW; for all generators, tracking, and responding to illegal disposal incidents; and for all off-site storage, transfer, treatment, and disposal facilities (NYSDEC, 2020).

CONTAINERS AND DISPOSAL METHODS

In addition to any state rules for disposing of regulated waste, CDC recommendations state that regulated waste must be placed in containers. These are recommendations only since the CDC is not a regulatory agency. The EPA has not enforced waste management regulations since the Medical Waste Tracking Act of 1988 expired in 1991. Waste disposal regulations are primarily controlled by the individual state environmental protection agencies (EPA, 2023a).

It is recommended that the containers be:

• Closable
• Constructed to contain all contents and prevent leakage of fluids during handling, storage, transport, or shipping
• Labeled or color-coded
• Closed prior to removal to prevent spillage or protrusion of contents during handling, storage, transport, or shipping

If outside contamination of the regulated waste container occurs, it must be placed in a second container meeting the above standards.

Sharps containers must be puncture resistant and located as close as possible to point of use. The container must be labeled with the universal biohazard symbol and the word biohazard or be color-coded red. Sharps containers must be maintained upright throughout use, replaced routinely, and not be allowed to overfill. Also, containers must be:

• Capable of maintaining impermeability after waste treatment
• Closed immediately prior to removal or replacement to prevent spillage or protrusion of contents during handling, storage, transport, or shipping
• Placed in a secondary container if leakage is possible; the second container must be:
  • Closeable
  • Constructed to contain all contents and prevent leakage during handling, storage, transport, or shipping
  • Labeled or color-coded
• Reusable containers must not be opened, emptied, or cleaned manually or in any other manner that would expose employees to risk of percutaneous injury (OSHA, 2023b).
• On-site incineration is an option for microbiologic, pathologic, and anatomic waste.
• Waste generated in isolation areas should be handled using the same methods used for waste from other patient-care areas.
• Containers with small amounts of blood remaining after laboratory procedures, suction fluids, or bulk blood can either be inactivated or carefully poured down a utility sink drain or toilet. No evidence indicates that bloodborne diseases have been transmitted from contact with raw or treated sewage.
• If treatment options are not available at the site of waste generation, transport in closed, impervious containers to the on-site treatment location or to another facility for treatment as appropriate.
• Store regulated medical wastes awaiting treatment in a properly ventilated area inaccessible to vertebrate pests. Use waste containers that prevent development of noxious odors.
• Regulated waste that has been decontaminated need not be labeled or color-coded.
  (Bio-MED, 2023)

Solid wastes can be disposed of in landfills or incinerators.

Of all the categories of regulated medical waste, microbiologic wastes pose the greatest potential for infectious disease transmission, and sharps pose the greatest risk for injuries (EPA, 2023b).

WARNING LABELS

Warning labels that include the universal biohazard symbol, followed by the term biohazard, must be included on:

• Bags and containers of regulated waste
• Refrigerators and freezers containing blood or other potentially infectious materials (OPIM)
• Other containers used to transport or ship blood or OPIM
• Contaminated equipment that is to be serviced or shipped (must also contain a statement relating to which portions of the equipment remain contaminated)

These labels are fluorescent orange, red, or orange-red. Bags used to dispose of regulated waste must be red or orange-red, and they too must have the biohazard symbol in a contrasting color readily visible upon them.

Red bags or red containers may be substituted for the biohazard label.

Linens and Laundry Management

The risk of actual disease transmission from soiled laundry is negligible. However, the hands of healthcare workers may be contaminated by contact with patient bed linens. Thus, common-sense hygienic practices for handling, processing, and storage of textiles are recommended. These practices include:

• Do not shake items or handle them in any way that may aerosolize the infectious agents.
• Avoid contact of one’s own body and personal clothing with the soiled items being handled.
• Wear gloves and other protective equipment, as appropriate, when handling contaminated laundry.
• Contain soiled items in a laundry bag or designated bin at the location where they were used, minimizing leakage.
• Do not sort or rinse textiles in the location of use.
• Label or color-code bags or containers for contaminated waste.
• If laundry chutes are used:
  • Ensure that laundry bags are securely closed before they are placed in the chute.
  • Do not place loose items in the laundry chute.
• For textiles heavily contaminated with blood or other body fluids, bag and transport in a manner that will prevent leakage.
• Do not use dry cleaning for routine laundering in healthcare facilities.
• For clean textiles, handle, transport, and store by methods that will ensure their cleanliness.
• If healthcare facilities require the use of uniforms, they should either make provisions to launder them or provide information to the employee regarding infection control and cleaning guidelines for the item based on the tasks being performed at the facility.
  (CDC, 2023c, 2023f)

OSHA’s Bloodborne Pathogens Standard requires employers to ensure that employees who have contact with contaminated laundry wear protective gloves and other appropriate PPE.

Employers are responsible for laundering reusable PPE. Work clothes such as uniforms are not considered to be PPE. Provided gowns or other PPE should be used to prevent soiling of uniforms.

Training healthcare workers who are responsible for housekeeping and management of linen and waste in appropriate infection control for their particular duties is essential for safe patient care (OSHA, 2023a).