Disinfection and Sterilisation in Healthcare: Processing Methods

Disinfection and sterilisation are essential parts of infection prevention in healthcare. Appropriate processing of instruments, materials and surfaces helps maintain a clean environment and reduce the transmission of infectious microorganisms. Preventing healthcare-associated infections can protect patients from serious complications, including deaths, and support safer recovery.

Types of processing

The archived source groups processing methods into five broad categories:

• Physical methods.
• Chemical methods.
• Biological methods.
• Mechanical methods.
• Combined methods.

These categories describe different approaches rather than five interchangeable ways to sterilise an item. CDC definitions distinguish cleaning, which removes soil, from disinfection, which inactivates many pathogens but does not necessarily eliminate bacterial spores, and sterilisation, which eliminates all forms of microbial life. Thorough cleaning is necessary before high-level disinfection or sterilisation.

Facilities combine appropriate processes to achieve effective treatment of materials and surfaces while making efficient use of staff time and resources. Several methods may be used during a working day, but their selection depends on the clinical task, item and required level of processing. Biological approaches should not be assumed to form part of every clinic’s routine cleaning programme.

Physical and chemical methods

Physical processing includes heat and other physical agents. An autoclave uses steam under pressure to sterilise compatible instruments through a validated cycle. Controlled dry heat is another sterilisation method for suitable items. The source also lists boiling and pasteurisation: these must be distinguished from validated sterilisation. UK Health and Safety Executive guidance explains that boiling cannot reliably eliminate every biological agent and may be used for disinfection, while heat-processing equipment needs maintenance and testing.

Pasteurisation is a thermal disinfection process that does not destroy bacterial spores. Ultraviolet (UV) radiation can inactivate microorganisms in air or on exposed surfaces, but its effectiveness depends on factors including contamination, intensity and exposure conditions. CDC guidance on UV and pasteurisation describes these limitations. UV systems require appropriate safety controls and, where used, supplement the facility’s cleaning and disinfection programme; they do not replace cleaning or provide reliable instrument sterilisation.

The source also describes heat treatment of bed linen. Healthcare textiles need an appropriate laundry process combining cleaning and, where required, thermal or chemical disinfection. The process must suit the fabric and intended use; ordinary clean bedding does not need to be described as sterile.

Chemical processing uses products selected for particular surfaces, materials or instruments. Chlorine-based products used on suitable sanitary fittings or floors are one example. Surface disinfectants, high-level disinfectants and chemical sterilants have different purposes. Follow the product’s directions, including concentration, contact time and safety precautions, and the item’s manufacturer’s instructions on material compatibility. A product described as gentler is not automatically effective against every pathogen or suitable for every material. CDC recommendations on cleaning and disinfection cover product selection and compatibility.

Mechanical cleaning and biological approaches

Mechanical cleaning removes dirt and contamination through practical housekeeping tasks. The source lists:

• Handling and changing bed linen. Although the source describes shaking bedding, used linen should be handled with minimal agitation rather than shaken.
• Washing floors.
• General damp cleaning of the ward.
• Removing used linen for laundering.

These tasks are part of routine care in wards and consulting rooms. Cleaning prepares surfaces for any disinfection required by the facility’s protocol. CDC advice on textiles and laundry recommends avoiding actions that disperse microorganisms into the air and placing soiled items in an appropriate bag or container. UV, where appropriate, remains an additional measure rather than a substitute for this work.

The source describes biological disinfection using bacteriophages, viruses that infect bacteria, and associates it with hospital wards. This should not be read as an established general method for routine ward disinfection. FDA research on bacteriophages investigates targeted therapy and decolonisation; this does not establish phages as a replacement for standard environmental cleaning and approved disinfectants.

Choosing the appropriate process

Reliable infection prevention depends on a coordinated programme, trained staff, agreed schedules and additional cleaning when contamination occurs. The required process depends on the item’s intended use and construction. Instruments entering sterile tissue require sterilisation; equipment contacting mucous membranes generally needs at least high-level disinfection. Noncritical equipment and environmental surfaces have different cleaning and disinfection requirements.

The source contrasts autoclaving with ultrasonic baths. An ultrasonic cleaner removes soil from suitable instruments; it does not replace the subsequent disinfection or sterilisation required for their intended use. Select a validated reprocessing method compatible with the device, following the manufacturer’s instructions. Where required, instruments are packaged before a validated sterilisation cycle. Afterwards, appropriate handling and storage arrangements protect the processed packs from recontamination.

Materials destined for disposal follow a separate healthcare-waste process. The source mentions incineration as a physical treatment. This means authorised waste treatment, not processing reusable instruments or burning waste in the clinical area. WHO guidance on healthcare waste describes the hazards of unsuitable incineration and alternatives such as autoclaving. The appropriate treatment depends on the waste type, local requirements and available facilities.

Original source: Zaplata — Disinfection and sterilisation in medicine: modern processing methods.