Disinfection Flashcards
Determining Efficacy:
TACT:
Temperature
Application
Concentration
Time
Disinfection temperature
○ Temperature plays a crucial role in good disinfection practices.
○ Disinfectants at a higher temperature generally exhibit greater antimicrobial activity and vice versa.
○ However, the higher the temperature the greater the risk of toxic vapor release. Exposure to toxic vapors can pose great risk to anyone exposed, making proper training, personal protective equipment, and taking great care critical to anyone handling disinfectants.
Disinfection application
○ Physical methods of application such as mopping, and wiping are generally more effective than non-physical methods like gassing or fogging which are often harder to control and less effective.
○ Physical methods like mopping and wiping are preferred because particles of dust/dirt adhere to surfaces via capillary adhesion and electrostatic forces. The physical action of mopping and wiping improves the efficacy of the disinfectant by helping to disturb and break these forces down.
○ When using a material for the application of any disinfectant some important factors to consider are:
§ Level of particulate generation (does this material release any particulate into the environment?)
§ Sorbency (does this material absorb a lot or very little of the solvent I’m using?)
§ Extractables (will the solvent or temperature extract anything from the material I’m using for application?)
§ Strength (is the material I’m using the appropriate strength for the disinfectant I’m using?)
Disinfection concentration
○ The correct concentration, or strength of the disinfecting agent being used is critical.
○ Concentrations that are too low may provide the opportunity for resistant strains of bacteria to prosper, leaving the surface contaminated.
○ But keep in mind, disinfectants that are too concentrated can also be less effective.
○ A high concentration of the disinfectant’s active ingredient will reduce the level of water, which in turn may diminish activity. Also consider how a higher concentration may affect the surface it is being applied to. A disinfectant that is too concentrated may lead to surface corrosion, residual residue, and increased costs. Most importantly, disinfecting agents that are too highly concentrated may be harmful to the user!
Disinfection time
○ For a disinfectant to work effectively it must remain in contact with the surface long enough to get the job done! * The contact time necessary to adequately disinfect varies depending on what agent is being used, and what it is being used on.
When disinfecting your hands, 30 seconds of vigorous scrubbing with soap and warm water is sufficient. When disinfecting equipment surfaces for example, 15 minutes contact time is required to adequately eliminate any contaminants.
What does sanitisation do?
Lowers the number of germs on surfaces or objects to a safe level, as judged by public health standards or requirements
What is sterilisation?
An extreme physical or chemical process that kills all forms of life.
Characteristics of Disinfectants
- Leave behind NO RESIDUE post cleaning
- Be WATER SOLUBLE (to aid in preparation and rinsing)
- Have a quick KILL RATE, minimizing contact time
- Possess a WIDE SPECTRUM of antimicrobial activity, capable of eliminating all bacteria and spores
- Be active at LOW CONCENTRATIONS
- Be NON-TOXIC and NON-CORROSIVE to both equipment and operators
- STABLE in both diluted and concentrated forms
- COMPATIBLE with all materials
- Have a cleaning effect that aids stain removal
- LOW FOAMING to allow ease of handling and filtration
- Not be affected by HARD WATER of ORGANIC MATERIAL * Non-toxic to the environment, making it easy to discard, low cost, and environmentally conscious!
Disinfection is
Disinfection of a controlled area after cleaning and or sanitization is carried out to kill actively growing or vegetative microorganisms. The work by destroying the cell wall of microbes. They do not kill all microorganisms, especially resistant bacterial spores ad gram positive rods, such as bacillus
Types of Disinfectants
Knowing the advantages and disadvantages of various disinfectants used in our processing environment is critical for maintaining and executing good disinfection practices. For example, one of the most common disinfectants used is Alcohol. Usually 70% Isopropyl Alcohol (IPA).
Some of the advantages of using 70% IPA as a disinfectant are:
* Broad spectrum activity (Destroys a wide array of contaminants)
* Rapid action (works fast)
* Easy to use
* Minimum residue is left behind (providing the water used is of high purity)
* Generally, not affected by organics or materials (works well with equipment)
There are also disadvantages to using alcohols as disinfectants.
- Alcohol is highly flammable, expensive in large quantities, and is NOT SPORICIDAL. So its use is not appropriate in all situations. Other types of disinfectants you’ll likely come across:
- Phenolic Compounds (Many of your typical household cleaners such as Pine-Sol and Lysol are Phenolic Compounds)
- Quaternary Ammonium Chloride Compounds or QUATS
- Iodophors (Betadine is a common Iodophor)
- Chlorine Compounds (Bleach)
Gluteraldehyde Each with its own unique advantages, disadvantages, and risks!
Validating Disinfectants
Validation is a critical aspect of all parts of our process, including good disinfection practices. First we take the suppliers data:
* Disinfectant type
* Chemical characteristics
* Contact time
* Antimicrobial activity
And then we conduct laboratory studies:
* Laboratory Studies (Dilution)-Determining the antimicrobial efficacy against various bacterial type cultures and typical bacteria isolated from the production environment
* Laboratory Studies (Surfaces)-Assessing the activity the disinfectant has on various surfaces, like plastics and metals, and any antagonistic effects it may have with other cleaning agents or disinfectants that maybe used routinely in the same area.
And finally we do plant-based studies:
Assessing the antimicrobial effect of the disinfectant and routine cleaning procedures used in the plant. Suppliers Data + Laboratory Data + Plant-Based Data = Assurance your disinfectant is effective.
Frequency of cleaning
A good disinfection program takes time and resources and must consider:
The nature of the process
Occupancy and manning levels
Traffic flows
Work / Shift pattern
Nature of surfaces
