CHAPTER 8

• What is the definition of sterilization?


  Killing or removal of all microorganisms in a material or an object.
• What does sterilization ensure regarding viable microorganisms?

  It renders a product free of all forms of viable microorganisms, including all bacterial spores.
• What is the origin of the term sterilization?


  It comes from the Latin word 'sterilis', meaning unable to produce offspring or barren.
• What does the sterilization process involve?


  Destruction or removal of all living cells, viable spores, viruses, and virioids from an object or habitat.
• What is disinfection?


  The destruction of pathogenic organisms associated with inanimate objects, usually by physical or chemical means.
• What forms of organisms does disinfection effectively target?


  It is effective against the vegetative forms of organisms but not necessarily against their spores.
• What is decontamination?


  Reduction of pathogenic microorganisms to a level where items are safe to handle without protective attire.
• What is a sanitizer?


  A chemical agent typically used in food-handling equipment and eating utensils to reduce bacterial numbers to meet public health standards.
• What does antisepsis involve?


  Inactivation or destruction by chemical means of microbes associated with living tissue or skin.
• What is ethyl alcohol classified as?


  Both an antiseptic and disinfectant.
• What does asepsis mean?


  Absence of significant contamination and prevention of the introduction of viable microorganisms.
• What is a germicide?


  An agent that destroys microorganisms.
• What is a sterilant?


  A chemical germicide that achieves sterilization.
• What is a high-level disinfectant?


  A germicide that kills all microbial pathogens except large numbers of bacterial endospores when used according to the labeling.
• What is an intermediate-level disinfectant?


  A germicide that kills all microbial pathogens except bacterial endospores when used according to the labeling.
• What is a low-level disinfectant?


  A germicide that kills most vegetative and lipid-enveloped or medium-sized viruses when used according to the labeling.
• What does minimum effective concentration (MEC) refer to?


  A measure of a liquid chemical germicide which still achieves the claimed microbicidal activity.
• What is cleaning (or precleaning)?


  The removal of foreign material from medical devices as part of the decontamination process.
• How is sterilization usually achieved?


  By steam under pressure or a sterilizing gas, such as ethylene oxide.
• What does degerming involve?


  Removal of microbes from a limited area, such as the skin around an injection site.
• What is the thermal death point?


  The lowest temperature at which all microorganisms in a liquid suspension will be killed in 10 minutes.
• What is the thermal death time?


  The minimal length of time in which all bacteria in a liquid culture will be killed at a given temperature.
• How does temperature affect thermal death time?


  The higher the temperature, the lower the time required to kill all bacteria.
• What is decimal reduction time (DRT or D value)?


  The length of time needed to kill 90% of the organisms in a given population at a specified temperature.
• Why is the decimal reduction time's objective to kill 90% of organisms and not 100%?


  100% is sterilization, and using 90% generally means controlling the growth of microbes.
• How does bacterial load affect chemical contact time?


  The higher the bacterial load, the higher the contact time needed for a chemical to work/kill.
• How does moist heat kill microorganisms?


  By coagulating proteins, which is caused by the breakage of hydrogen bonds.
• What role do water molecules play in moist heat sterilization?


  They help disrupt the hydrogen bonds and other weak interactions that hold proteins in their three-dimensional structure.
• What is boiling used for in sterilization?


  Steam or boiling water at 100°C is used in preparing syringes, needles, and instruments for minor surgery.
• What does boiling kill?


  Kills vegetative forms and viruses in 5 minutes and also some spores.
• Should tools used in major surgeries be disinfected or sterilized?


  They should be sterilized.
• What is a disadvantage of boiling equipment?


  It may affect the sharpness of equipment like scissors and scalpel blades.
• What types of spores are not killed by boiling?

  Resistant spores from Clostridium tetani and common Bacillus species can survive boiling for several hours.
• What happens to instruments after boiling for about 30 minutes?


  It damages the cutting edge of instruments.
• What is the purpose of steam under pressure (autoclave)?


  To kill resistant spores at 121°C for 15 minutes.
• Why should foil not be used in an autoclave?


  Because it is impervious to steam.
• What materials are typically sterilized using an autoclave?


  Heat-resistant materials such as glassware and surgical dressings.
• Why is 30 minutes needed to fully use an autoclave?


  15 minutes to prepare the autoclave to the ideal temperature and 15 minutes to maintain that temperature.
• What factors must be considered when using an autoclave?


  Type of material, volume of material, packaging, cycle selection, loading, maintenance, and safety.
• What should be done to ensure effective autoclaving?


  Materials must be loaded in a way that allows for even steam penetration.