ATrain Education


Continuing Education for Health Professionals

Infection Control and Prevention

Module 8

Element V: Cleaning, Disinfection, and Sterilization

Creation and maintenance of a safe environment for patient care in all healthcare settings through application of infection control principles and practices for cleaning, disinfection, and sterilization.

Application of accepted infection control principles helps maintain a safe environment for both patients and healthcare workers. This includes proper use of Standard Precautions and an understanding ability to apply proper techniques for cleaning, disinfection, sterilization, and reprocessing of medical equipment.

Environmental Control Measures

[The following section is derived from CDC (2003).]

Microorganisms are present in great numbers in moist, organic environments, and some can persist under dry conditions. Contaminated surfaces have been associated with transmission of infections.

The transfer of a microorganism from an environmental surface to a patient is largely via hand contact with the surface. Although hand hygiene is important to minimize the impact of this transfer, cleaning and disinfecting environmental surfaces is fundamental in reducing their potential contribution to the incidence of HAIs.

Environmental Cleaning

All work areas must be maintained in a clean and sanitary condition. The employer is required to determine and implement a written schedule for cleaning and disinfection based on the location within the facility, type of surface to be cleaned, type of soil present, and tasks or procedures being performed. All equipment, environmental and working surfaces must be properly cleaned and disinfected after contact with blood or other infectious material. Contaminated broken glassware must be removed using mechanical means, like a brush and dustpan or vacuum cleaner.

Chemical germicides and disinfectants at recommended dilutions must be used to decontaminate environmental surfaces. Consult the Environmental Protection Agency (EPA) lists of registered sterilants, tuberculocidal disinfectants, and antimicrobials with HIV/HBV efficacy claims to ensure that the disinfectant is appropriate.


OSHA defines contaminated laundry as “laundry which has been soiled with blood or other potentially infectious materials or may contain sharps.” Contaminated textiles and fabrics often contain high numbers of microorganisms from body substances, including blood, skin, stool, urine, vomitus, and other body tissues and fluids. Disease transmission attributed to healthcare laundry has involved contaminated fabrics that were handled inappropriately (eg, the shaking of soiled linens). Bacteria, viruses, fungi, and ectoparasites such as scabies presumably have been transmitted from contaminated textiles and fabrics to workers either via direct contact or via aerosols of contaminated lint generated from sorting and handling contaminated textiles.

Fabrics, textiles, and clothing used in healthcare settings are disinfected during laundering and generally rendered free of vegetative pathogens (hygienically clean), but they are not sterile. The antimicrobial action of the laundering process results from a combination of mechanical, thermal, and chemical factors. Dilution and agitation in water remove substantial quantities of microorganisms. Soaps and detergents function to suspend soils and also exhibit some microbicidal properties. Hot water provides an effective means of destroying microorganisms. Chlorine bleach is an economical, broad-spectrum chemical germicide that enhances the effectiveness of the laundering process.

Laundry that is or may be soiled with blood or other potentially infectious material, or may contain contaminated sharps, must be treated as though contaminated. Contaminated laundry must be bagged at the location where it was used, and should not be sorted or rinsed in patient-care areas. It must be placed and transported in bags that are labeled or color-coded.

Laundry workers must wear protective gloves and other appropriate personal protective clothing when handling potentially contaminated laundry. All contaminated laundry must be cleaned or laundered so that any infectious agents are destroyed.

Infectious material may be present on the clothing of healthcare workers. In a study examining the microbial contamination of medical students’ white coats, the students perceived the coats as “clean” as long as the garments were not visibly contaminated with body substances, even after wearing the coats for several weeks. The heaviest bacterial load was found on the sleeves and the pockets of these garments; the organisms most frequently isolated were Staphylococcus aureus, diphtheroids, and Acinetobacter spp.

Appropriate Ventilation

Engineering controls to contain or prevent the spread of airborne contaminants center on local exhaust ventilation, general ventilation, and air cleaning. General ventilation encompasses: (a) dilution and removal of contaminants via well-mixed air distribution of filtered air; (b) directing contaminants toward exhaust registers and grilles via uniform, non-mixed airflow patterns; (c) pressurization of individual spaces relative to other spaces; and (d) pressurization of buildings relative to the outdoors and other attached buildings.

Waste Management

Both science and regulation address the management of waste from healthcare. In addition to complying with regulation, the most practical approach to medical waste management is to identify wastes that represent a sufficient potential risk of causing infection during handling and disposal and for which some precautions are likely prudent. Healthcare facility medical wastes targeted for handling and disposal precautions include microbiology laboratory waste, pathology and anatomy waste, blood specimens from clinics and laboratories, blood products, and other body-fluid specimens.

Although any item that has had contact with blood, exudates, or secretions may carry pathogens, treating all such waste as infective is neither practical nor necessary. Federal, state, and local guidelines and regulations specify the categories of medical waste that are subject to regulation and outline the requirements associated with treatment and disposal. The categorization of these wastes has generated the term regulated medical waste, which is defined as any of the following:

  • Liquid or semi-liquid blood or other potentially infectious materials (OPIM)
  • Contaminated items that would release blood or OPIM in a liquid or semi-liquid state, if compressed
  • Items that are caked with dried blood or OPIM and are capable of releasing these materials during handling
  • Contaminated sharps
  • Pathological and microbiological wastes containing blood or OPIM

Medical wastes require careful disposal and containment before collection and consolidation for treatment. OSHA has dictated initial measures for discarding regulated medical-waste items. These measures are designed to protect the workers who generate medical wastes and who manage the wastes from point of generation to disposal. A single, red, leak-resistant biohazard bag is usually adequate for containment of regulated medical wastes, provided the bag is sturdy and the waste can be discarded without contaminating the bag’s exterior. If the outside of the primary bag is contaminated or punctured, it must be placed into a second biohazard bag. All bags should be securely closed for disposal.

Puncture-resistant containers located at the point of use are used to discard sharps, including needles and syringes, scalpel blades, unused sterile sharps, and discarded slides or tubes with small amounts of blood. To prevent needlestick injuries, needles and other contaminated sharps should not be recapped, purposefully bent, or broken by hand.

Transporting and storing regulated medical wastes within the healthcare facility while awaiting terminal treatment is often necessary. Both federal and state regulations address the safe transport and storage of on- and off-site regulated medical wastes. Healthcare facilities are required to dispose of medical wastes regularly to avoid accumulation.

Medical wastes requiring storage should be kept in labeled, leakproof, puncture-resistant containers under conditions that minimize or prevent foul odors. The storage area should be well ventilated and be inaccessible to pests. Any facility that generates regulated medical wastes should have a regulated medical waste management plan to ensure health and environmental safety as per federal, state, and local regulations (CDC, 2003).

Of all the categories comprising regulated medical waste, microbiologic wastes such as untreated cultures, stocks, and amplified microbial populations pose the greatest potential for infectious disease transmission, while sharps pose the greatest risk for injuries (CDC, 2003).

Sterilization and Disinfection

In the United States, nearly 50 million surgical procedures and even more invasive medical proceduresincluding more than 5 million gastrointestinal endoscopiesare performed each year. Each procedure involves contact by a medical device or surgical instrument with a patient’s sterile tissue or mucous membranes. A major risk of all such procedures is the introduction of pathogens that can lead to infection. Failure to properly disinfect or sterilize equipment carries not only risk associated with breach of host barriers but also risk for person-to-person transmission and transmission of environmental pathogens such as Pseudomonas aeruginosa (Rutala et al., 2008).

Because sterilization of all patient-care items is not necessary, healthcare policies must identifyprimarily on the basis of the items’ intended usewhether cleaning, disinfection, or sterilization is indicated. Multiple studies in many countries have documented lack of compliance with established guidelines for disinfection and sterilization. Failure to comply with scientifically based guidelines has led to numerous outbreaks (Rutala et al., 2008).

Sterilization is a process that destroys or eliminates all forms of microbial life and is carried out in healthcare facilities by physical or chemical methods. Sterile and non-sterile are absolute conceptsblack and white with no gray. If a sterile item is touched by anything non-sterile, the formerly sterile item is no longer sterile.

Disinfection is a process that eliminates many or all pathogenic microorganisms, except bacterial spores, on inanimate objects. In healthcare settings, objects are usually disinfected using liquid chemicals or wet pasteurization. When selecting a disinfectant, consider its properties. There are two levels of disinfection:

  • High-level disinfectionused to clean patient-care equipment that touches mucous membranes
  • Low-level disinfectionused to clean the hospital environment or items that touch intact skin

Products for sterilization and disinfection are licensed for the appropriate use by the FDA. Always be sure the product you plan to use is licensed for the intended purpose. And always use the lowest level of product that will do the job, since all disinfectants are toxic by their nature.

Cleaning is the removal of visible soil (organic and inorganic material) from objects and surfaces; normally it is accomplished manually or mechanically using water with detergents or enzymatic products. Thorough cleaning is essential before high-level disinfection and sterilization because inorganic and organic materials that remain on the surfaces of instruments interfere with the effectiveness of these processes.

Decontamination removes pathogenic microorganisms from objects so they are safe to handle, use, or discard (Rutala et al., 2008).

Reprocessing Reusable Medical Equipment

[This section is taken largely from NYS DOH, 2010.]

Healthcare facilities should follow manufacturer’s recommendations for proper cleaning, disinfection, and sterilization of all reusable equipment. In addition, good practices suggest the following:

  • Designate staff responsible for maintaining proper reprocessing procedures.
  • Ensure designated staff members are properly trained in reprocessing each piece of equipment.
  • Follow FDA guidelines for reprocessing equipment designated for single use.
  • Maintain a log of all equipment reprocessing.

Instruments, medical devices, and equipment should be managed and reprocessed according to recommended and appropriate methods regardless of a patient’s diagnosis except for cases of suspected prion disease. Special procedures are required for handling brain, spinal, or nerve tissue from patients with known or suspected prion disease (such as Creutzfeldt-Jakob disease). Consultation with infection control experts before performing procedures on such patients is recommended.

Industry guidelines as well as equipment and chemical manufacturer recommendations should be used to develop and update reprocessing policies and procedures. Written instructions should be available for each instrument, medical device, and equipment reprocessed. Potential for contamination is dependent upon:

  • Type of device or environmental surface
  • Potential for external or internal contamination
  • Frequency of hand contact with device or surface
  • Potential for contamination with body substances or environmental sources of microorganisms
  • Level of contamination

Reprocessing of medical equipment involves several steps: (1) pre-cleaning, (2) cleaning, and (3) disinfection or sterilization. Pre-cleaning, which removes soil, debris, and lubricants from internal and external surfaces should be done as soon as possible after use. Cleaning can be done either manually (scrubbing with brushes) or mechanically using automated washers.

Equipment used for cleaning must be used appropriately and cleaning solutions must be changed according to the manufacturer’s guidelines. Once cleaning is completed, equipment must be disinfected or sterilized depending on the intended use of the item. Disinfection requires sufficient contact time with chemical solution, while sterilization requires sufficient exposure time to heat, chemicals, or gases.

Critical items, instruments and medical devices, require sterilization. Critical items are those items that enter sterile spacesthey must be sterile. Critical items confer a high risk for infection if they are contaminated with any microorganism. This category includes surgical instruments, cardiac and urinary catheters, implants, and ultrasound probes used in sterile body cavities (Rutala et al., 2008).

Semi-critical items are those items that touch intact mucous membranesthey must receive at least high-level disinfection, which kills all microbial life except spores. This category includes respiratory therapy and anesthesia equipment, some endoscopes, laryngoscope blades, esophageal manometry probes, cystoscopes, anorectal manometry catheters, and diaphragm fitting rings (Rutala et al., 2008).

Non-critical items are those items that touch intact skin but not mucous membranes. Intact skin acts as an effective barrier to most microorganisms; therefore, the sterility of items coming in contact with intact skin is “not critical.” Examples of noncritical patient-care items are bedpans, blood pressure cuffs, crutches, and computers. In contrast to critical and some semi-critical items, most non-critical reusable items may be decontaminated where they are used and do not need to be transported to a central processing area (Rutala et al., 2008).

Factors That Contribute to Contamination During Reprocessing

At any point in reprocessing or handling, breaks in infection control practices can compromise the integrity of instruments, medical devices, or equipment. Specific factors include:

  • Failure to reprocess or dispose of items between patients
  • Inadequate cleaning, disinfection, or sterilization
  • Contamination of disinfectant or rinse solutions
  • Improper packaging, storage, and handling
  • Inadequate or inaccurate record keeping of reprocessing requirements

Differing levels of disinfection and sterilization methods and agents are based on the area of professional practice, setting, and scope of responsibilities. Professionals who practice in settings where handling, cleaning, and reprocessing is performed elsewhere should understand core infection control concepts and principles. A thorough understanding of Standard Precautions, personal protective equipment, and principles of cleaning, disinfection, and sterilization are essential.

Designation and physical separation of patient care areas from cleaning and reprocessing areas are strongly recommended. Each medical facility must determine appropriate reprocessing practices and select appropriate methods, taking into consideration:

  • Antimicrobial efficacy
  • Time constraints and requirements for various methods
  • Compatibility of equipment and materials
  • Toxicity
  • Residual effect (the product’s antimicrobial effect when used repeatedly over a number of days)
  • Ease of use
  • Stability (concentration, potency, efficacy of use, and effect of organic material)
  • Odor
  • Cost
  • Monitoring requirements

Single-Use Devices

A single-use device (SUD) is a device that is intended for one use or on a single patient during a single procedure. An unused SUD is referred to as an original device. A reprocessed SUD is an original device that has previously been used on a patient and has been subjected to additional processing and manufacturing for the purpose of an additional single use on a patient (FDA, 2006). Approximately twenty to thirty percent of U.S. hospitals report that they reuse at least one type of SUD.

The reprocessing of certain SUDs is permitted in the United States under the Federal Food, Drug, and Cosmetic Act. In 2002 the Medical Device User Fee and Modernization Act established regulations requiring that all reprocessed SUDs be clearly labelled as “reprocessed” and contain the name of the reprocessor. The act also directed the FDA to increase its oversight of these devices by identifying reprocessed SUDs that should not be marketed unless the reprocessing company first provided data demonstrating effective cleaning, sterilization, and functional performance (GAO, 2008).

Many sources have repeatedly warned about the potential risks of infection from reprocessed SUDs or their failure to function properly, and their use has been controversial for more than two decades. The American public has expressed increasing concern regarding the risk of infection and injury when reusing medical devices intended and labeled for single use (Rutala et al., 2008). Reprocessing of SUDs is banned in France and strongly discouraged in Great Britain and other countries in Europe. The Department of Veterans Affairs, which operates one of the largest healthcare systems in the United States, prohibits their use entirely (GAO, 2008).

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