- Sterilization is the killing or removal of all microorganisms, including bacterial spores which are highly resistant. Sterilization is an absolute term, i.e. the article must be sterile meaning the absence of all microorganisms
- Disinfection is the killing of many, but not all microorganisms. It is a process of reduction of number of contaminating organisms to a level that cannot cause infection, i.e. pathogens must be killed. Some organisms and bacterial spores may survive.
- Disinfectants are chemicals that are used for disinfection. Disinfectants should be used only on inanimate objects
- Antiseptics are mild forms of disinfectants that are used externally on living tissues to kill microorganisms, e.g. on the surface of skin and mucous membranes.
Sterilisation Techniques
• Steam
o 120 degrees
o Autoclave
o 13 minutes
o Pressurised 2 atm
o Kills bacteria, fungi, viruses, spores
o To kill prions 60 minutes required
o Can’t be used for endoscopes
• Dry heat
o 170 degrees
o 1 hour or 4 if grease present
• Ethylene oxide gas
o Telescopic instruments, plastic, rubber, electrical cords
o Destroys bacteria, virus and fungi
• Peroxyacetic acid
o Used for scopes
• Gluteraldehyde
• Hydrogen peroxide gas
Most techniques employ biological test indicators used to show that process has been completed. The use of different techniques depends on:
- Type of equipment
- Urgency of sterilization
- Local costs
- Local availability