This method involves exposing the packed materials to radiation for sterilization. There are two types of radiations available for sterilization i.e
a) non-ionic and
b) ionic radiation.
a) Non-ionic radiations are safe to the operator of sterilization, and they are like Ultra Violet radiations, they can be used even at the door entrances to prevent entry of live microbes through the air.
b) Ionizing radiation sterilization. They are powerful radiation and very useful for sterilization. The operator needs to protect himself from exposure from these radiations by use of special clothing.
Examples: X-rays, γ-rays, etc.
Filtration
In this method, liquids are filtered through bacterial filters to remove any microbes present. This method is very effective for sterilization of heat sensitive liquids. The chances of clogging and long time duration for the process to happen are drawbacks.
For sterilization three types of filters are used:
A) Membrane filters: These are thin filters which are made of cellulose. They can be employed for online sterilization during injection by placing the membrane between the syringe and needle. Used for sterilization of solvents, gasses.
B) Seitz filters: These are made of asbestos or other material. They are pad like and thicker than membrane filters. They do not rupture during filtration. But the solution might get absorbed by the filter pad itself.
C) Sintered glass filters: These are made of glass and hence do not absorb liquids during filtration. The disadvantage is that they are very brittle and break easily.
D) Candle filters: These are made of clay like diatomous mud. This special mud has minute pores made by algae. The filters have many minute lengthy pores. The microbes get stuck during their travel through the pore in the candle.
Chemical Methods of Sterilization:
The materials are subjected to sterilization by using toxic gasses. The gas penetrates quickly into the material like steam so, the sterilization is effective. But the chances of explosion and cost factors are to be considered.
Gasses used for sterilization are very poisonous. The commonly used gas is ethylene oxide with a combination of carbon-dioxide. Carbon dioxide is added to minimize the chances of an explosion.
Hydrogen Peroxide Sterilization, also known as hydrogen peroxide gas sterilization, is a low temperature sterilization process commonly used to sterilize heat-sensitive devices. A hydrogen peroxide sterilization process involves H2O2 vapor filling the sterilizer chamber, contacting and sterilizing exposed device surfaces. Once the sterilization cycle has completed, the vapor is vacuumed from the chamber and converted to water and oxygen
LECTURER IN CHARGE: MRS ALBERT
BLOGGER: HOC TEMIYEMI
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