Other sterilisation processes

• What are the three main sterilisation processes mentioned?

  Steam, any heat, and ionizing radiation
• What is another method of sterilisation mentioned besides steam and heat?

  Gaseous sterilisation
• How does dry heat inactivate microorganisms?

  By oxidation
• Why is dry heat sterilisation considered less expensive than hydrolysis for inactivating bacterial spores?

  Because it requires lower operational costs
• What is a requirement for dry heat sterilisation in terms of temperature and time?

  It requires higher temperatures for a longer period of time
• What is the margin for error in dry heat sterilisation compared to other heat conditions?

  It has a smaller margin for error and must be controlled carefully
• What types of items are typically sterilised using dry heat?

  Items that can't be sterilised by moist heat or other methods
• What is the temperature range for dry heat sterilisation?

  150-180°C
• What is the typical time required for dry heat sterilisation?

  2-4 hours
• What higher temperature is needed for pyrogen destruction during dry heat sterilisation?

  250°C for 20 minutes
• What is an essential design feature of a hot air oven used for dry heat sterilisation?

  An insulated stainless steel chamber
• What are the requirements for a hot air oven used in dry heat sterilisation?

  • Raise temperature quickly, even heat distribution, maintain temperature within narrow limits
• How does the operator interact with the steriliser tunnels?

  By loading, switching on, and unloading the steriliser
• How are items sterilised in steriliser tunnels?

  Items are sterilised on a conveyor belt passing through the tunnel
• What is the main use of dry heat sterilisation?

  For sterilisation and depyrogenation of glassware containers
• What types of substances cannot be subjected to moisture during sterilisation?

  H₂O soluble powders and materials not penetrable by steam
• What is a disadvantage of dry heat sterilisation regarding heating time?

  It may take a long time to heat up
• How does the temperature requirement for dry heat compare to moist heat?

  It must be higher and longer than for moist heat
• What is a potential issue with some objects during dry heat sterilisation?

  Some objects may oxidise at high temperatures
• What is a disadvantage of simple ovens without fans in dry heat sterilisation?

  They may have poor uniformity and large temperature variations
• What is the primary use of gaseous sterilisation?

  For temperature-sensitive materials
• What are the two main gases used in gaseous sterilisation?

  Ethylene oxide and formaldehyde
• What is an advantage of gaseous sterilisation for sensitive materials?

  It is a good alternative for materials sensitive to heat or radiation
• What is a disadvantage of gaseous sterilisation regarding throughput?

  It is slow and not suitable for high throughput sterilisation
• What is the boiling point of ethylene oxide?

  11°C
• What are the safety concerns associated with ethylene oxide?

  It is toxic, an irritant, and a carcinogen
• How does ethylene oxide interact with materials?

  It is readily absorbed by fabrics and plastics
• What is a significant hazard of ethylene oxide?

  It is highly flammable and explosive when mixed with oxygen
• What is a broad-spectrum advantage of ethylene oxide?

  It is non-selective and effective against a wide range of microorganisms
• What are the disadvantages of ethylene oxide?

  • Expensive, difficult to handle, and potentially dangerous
• What is the explosive risk associated with ethylene oxide?

  It is explosive if present at 3.6% concentration in air
• What humidity levels are required for ethylene oxide sterilisation?

  15°C at 45-63% or room temperature if longer
• What is the boiling point of formaldehyde?

  -19°C
• What is formaldehyde used for besides sterilisation?

  For preservation of biological specimens
• How is formaldehyde gas obtained for sterilisation?

  By heating formalin with steam
• What is the method of use for the WES sterilisation process?

  Operates with sub-atmospheric pressure steam
• What is a disadvantage of the WES sterilisation process?

  It is toxic and has low penetration power
• What is the primary target of radiation sterilisation?

  DNA
• What is the most common type of radiation used for sterilisation?

  Gamma rays
• How does radiation cause damage to microorganisms?

  By direct damage to DNA or through the radiolysis of water