Disinfection is defined as a process that inactivates infectious agents, using either thermal (moist or dry heat) or chemical means. The level of disinfection achieved depends on the temperature, exposure time and/or type of chemical disinfectant used.
High-level disinfection — this is the minimum treatment recommended for reprocessing REUSABLE INSTRUMENTS that cannot be sterilised, for use in semi-critical sites or when there are specific concerns regarding contamination of surfaces with species of mycobacteria – for example, mycobacterium tuberculosis.
Low-level disinfection — this is the minimum treatment recommended for reprocessing REUSABLE INSTRUMENTS for use in non-critical sites.
Thermal disinfection can be achieved in a thermal washer–disinfector by choosing the appropriate cycle. If items can withstand heat and moisture and do not require sterilisation, then thermal disinfection using moist heat at temperatures and times that destroy pathogenic agents is the simplest, most efficient and cost-effective method of disinfection.
Automated equipment, such as washer-disinfectors are recommended for use in thermal disinfection processes. As we know the level of disinfection depends on the water temperature and the exposure time. Thermal washer–disinfectors can be programmed to deliver a range of disinfection levels, depending on the cycle selected (i.e. set temperature and exposure times). If carried out appropriately the thermal disinfection process should provide adequate assurance of the required microbial lethality.
Note: The manufacturers’ instructions should be followed to achieve the required level of disinfection.
Chemical disinfection can be achieved with a compatible REUSABLE INSTRUMENTS-grade disinfectant of the required level, used alone or in conjunction with a chemical washer-disinfector.
Disinfection should be carried out using a thermal disinfection process whenever practicable. Chemical disinfection should be employed only when required by the REUSABLE INSTRUMENTS manufacturers’ instructions. The ability of chemical disinfectants to effectively inactivate contaminating infectious agents depends on a number of factors, including the initial number of agents present, temperature, pH and concentration hence the importance of robust cleaning . Only REUSABLE INSTRUMENTS disinfectants or sterilants are suitable for use with REUSABLE INSTRUMENTS.
Chemical disinfection processes should provide adequate assurance of the required microbial lethality. Chemical disinfection processes should be validated microbiologically (usually by the disinfectant manufacturer). This should define the concentration, contact time and minimum/maximum temperatures.
It is important to remember that the effectiveness of the disinfection process cannot be verified retrospectively by inspection or testing of the product alone, and can only be guaranteed if correct conditions are created throughout the washer-disinfector chamber and the load during every cycle, therefore the separation of reusable instrument tray sets prior to cleaning and disinfection is vital.
Place reusable instruments in mesh basket in a manner which ensures effective cleaning/disinfection. Do not place reusable instruments one on top of the other.
Overloaded baskets will result in ineffective cleaning/disinfection.
Arrange REUSABLE INSTRUMENTS in an orderly fashion in mesh trays so that all surfaces are exposed to the action of an automated cleaner, if used. Placing each jointed REUSABLE INSTRUMENTS in the open position in the mesh basket. If extra mesh baskets are required for cleaning/disinfection purposes of an REUSABLE INSTRUMENTS set, a tray identification label should be placed in the extra baskets to identify the set name and number. Ensure heavy retractors and/or other heavy REUSABLE INSTRUMENTS are placed on the bottom or in a separate tray/baskets. Secure small and light items with a hold down screen or by other means, to ensure they are not free to move around during the cleaning process. Place scissors, lightweight REUSABLE INSTRUMENTS, and microsurgical REUSABLE INSTRUMENTS next. Receivers and gallipots should not be placed over REUSABLE INSTRUMENTS, as they may interfere with the cleaning/disinfection process.