Sterilisation methods Copy

Sterilisation Methods

Autoclave

• Works like a pressure cooker.
• Consists of 2 chambers. Water in the lower chamber and instruments in the upper chamber.
• The principle of sterilisation is moist heat.
• The water boils in the lower chamber and steam are released towards the upper chamber. Instruments are left in the unit for 10 – 20 min. Afterward, instruments must be placed in a sterile and clean container.
• The moist heat autoclave operates at 121°C and is considered a very effective means of sterilisation.
• Other types available, e.g., dry heat autoclave, vacuum autoclave, flash instrument autoclave.
• The time and temperature of dry heat autoclave is 160°C (320°F) for 2 hours or 180°C (356°F) for one hour.
• Consult manufacturer’s instructions and local government laws and regulations on sterilisation times and temperatures.

Advantages of an Autoclave

• Economical and very effective
• Non-toxic on instruments
• Easy to operate

Disadvantages of an Autoclave

• Sharp instruments can become blunt.
• Metal instruments might rust. Recommend use of stainless-steel instruments.
• Expensive
• Plastic instruments will be damaged.
• Autoclaves will need to be kept clean.
• Regular servicing and calibration are required of the device.

Glass Bead Steriliser

• • • Operates at approximately 300°C.
    • Metal instruments will thus be completely sterilised within minutes.
    • Only the parts covered with beads will be sterilised.
    • The unit takes + 20 – 30 minutes to warm up before sterilisation can take place.
    • If more than one instrument is placed in the container, a longer time must be added for sterilisation.
    • Consult manufacturers` instructions and local government laws and regulations on sterilisation times and temperatures

Wet Sterilisation (Chemical)

Asepsis can be obtained by washing down all surfaces, walls, floors, treatment beds, tiles, trolleys, work surfaces, basins etc. after basic cleaning with an antiseptic solution. EG: Antiseptic solution concentrates, diluted according to manufacturers’ instructions. Towels can also be disinfected in this method. If metal tools are sterilised by this method, the liquid must contain a rust inhibitor.

UV Cabinet

• They are used for the maintenance of your sterilisation process.
• Basically, used as a storage unit.
• They are not used for sterilisation only for sanitation.
• This cabinet will keep your item as clean as it was when you first inserted it.

Antiseptics and Disinfectants

Antiseptic

A diluted disinfectant that is safe to apply to the skin. Its’ task is to slow down multiplication, growth and in some cases may destroy/kill micro-organisms if the strength of the solution is correct, e.g., some soaps (hands), alcohol and hydrogen peroxide etc.

Disinfectant

A chemical agent which destroys or kills all micro-organisms. Safe to apply on surfaces but too toxic to be applied directly onto the skin, e.g., Quaternary Ammonium compound/Quats, formalin, ethyl or grain alcohol.