This document discusses sterilization, disinfection, and antisepsis. It defines sterilization as a process that destroys all microorganisms through methods such as heat, radiation, or chemicals. Disinfection reduces microbes but does not kill all bacteria or spores. Antiseptics are antimicrobial agents applied to living tissue to prevent infection of wounds and cuts. The document outlines various sterilization methods including steam sterilization and filtration and provides examples of commonly used disinfectants and antiseptics.

1. STERILIZATION,
DISINFECTION and
ANTISEPSIS
PRESENTED BY
D. JASMINE PRIYA, B.Sc., DCA., M.Sc., PGDCLT.
DR. NGP ARTS AND SCIENCE COLLEGE
COIMBATORE

2. STERILIZATION

3. What is sterilization ?
 Sterilization is a process of destroying all germs including persistent microorganisms and bacteria.
 The whole process is difficult to achieve because chemicals are not always able to kill unwanted or hazardous leftovers.
 There are many methods to kill the microorganisms including Ultraviolet and ionizing radiations, altering DNA to hinder
any replication.
 However Ultraviolet sterilization always does not provide the most effective outcomes or ease of validation as moist heat
(steam) sterilization.
 Microorganisms and temperature correlate with each other.
 As temperature rises the microorganisms become active but still do not completely die.
 The temperature and time required to deactivate Prions are significantly higher.
 In order to destroy microbes, steam molecules are being condensed and then transferred in 2500 joules per gram effectively
heating the microbes to completely destroy them.
 There are other methods to destroy the microorganisms which include low heat conditions and boundary layer effects,
which can insulate and protect microorganisms.

4.  The basic aim of the process of sterilization is complete destruction of microbes that are undesired in order to
maintain a clean environment.
 This can be achieved by a variety of procedures each with its positive and negative aspects.
 The ideal sterilizing technique should deactivate microbiological and undesired biological material such as prions
rapidly and effectively.
 It should provide a less toxic environment, conclude fewer health risk operators and transition to sterile objects, all
while allowing for maximum adaptability while accommodating a variety of materials.
 The goal of the process is to remove any physical difficulties in sterilization and achieve this in a cost-effective way.
Meeting all of these requirements, on the other hand, is frequently impossible.
 As a result, including many of these elements is frequently a secondary issue, with the primary goal being to
achieve asepsis in a functional end product.

5. Purpose of sterilization
 sterilization aims to destroy all microorganisms and their spores in the
process.
 mushroom growers prefer Pasteurization because it scales easily and
does not require specialized equipment.
 In order to ensure that your laboratory and lab equipment are
completely free of contaminants, you should use sterilizing.
 A 100% kill rate is achieved by sterile processing, which inactivates
All microorganisms, including viruses, bacteria, fungi, and spores.

6. Methods of Sterilization
1. Sterile Filtration
 Filtration is an option to consider if a fluid material needs to be sterilized
 A liquid or gas can pass through a sterilizing filter membrane, which creates a mechanical barrier to all particles larger
than the membrane's pores.
 Larger microorganisms are retained behind the filter, ensuring that they do not enter the filtrate.
 Filtration, on the other hand, has no such consequences, as it only removes particles larger than a specific size.
 As a result, filtering is a viable option for highly volatile and reactive fluids.
 Filtration is the preferred method of sterilizing heat sensitive liquid and gases without exposure to denaturing heat.
Rather than destroying contaminating microorganisms, it simply removes them.
 It is the method of choice for sterilizing antibiotic solutions, toxic chemicals, radioisotopes, vaccines, and
carbohydrates, which are all heat-sensitive.
 The liquid or gas is passed through a filter, a device with pores too small for the passage of microorganisms, but large
enough to allow the passage of the liquid or gas. These filters are made of different materials;

7. Materials Name of the filter
Asbestos pad Seitz filter
Diatomaceous earth Berkefeld filter
Procelain Chamberland-Pasteur filter
Sintered glass disks Sintered glass filter
Cellulose Membrane filter
Borosilicate glass fiber HEPA filter
Clay, mud Candle filter

9. Working Mechanism of Filtration Sterilization
Filters work by physically trapping particles larger than the pore size and by
retaining somewhat smaller particles via electrostatic attraction of the particles
to the filters. Besides porosity, other factors also influence the efficiency of
filtration, they are:
• electric charge of the filter
• electric charge carried by the organisms
• nature of the fluid being filtered

10. Advantages of Filtration Sterilization
 Less capital intensive
 Suitable for heat-sensitive liquids (infusions, vaccines, hormones, etc).
 Large volume of liquids can be filtered reasonably fast
Limitations of Filtration Sterilization
 Only liquids and gases can be sterilized by this process
 Filters are expensive to replace, especially nano-filters
 Inherent limitations of materials used in filters affect the efficacy of this process i.e,
breakage of glass filters, rupture of the membrane filter and absorption of the filtrate by
Sietz filter
 Clogging may occur

11. DISINFECTION

12. 2. Disinfection
 Most pathogens are eliminated, but not all types of bacteria are.
 Microbial contamination is reduced through disinfection.
 Unlike chemical sterilization, chemical disinfection does not
kill spores.
 Freshly produced 10% bleach and 70% ethanol are two often
used laboratory disinfectants. High-level disinfection consists
of a high percentage of chemicals effectively killing vegetative
microorganisms.
 The intermediate approach kills viruses but not as effectively
whereas the low level kills only some inactive viruses.

13. What is Disinfectant?
 A disinfectant can be defined as an antimicrobial agent that can be applied on the surface of
some objects in order to destroy the microorganisms residing on it.
 A disinfectant is an antimicrobial agent.
 It is not necessary that a disinfectant will kill all the microorganisms.
 It is not as effective as sterilization.
 The process of sterilization kills all types of living forms but a disinfectant kills only
certain types of microbes.
 It is generally applied to a floor or a drainage system.
 Most of the popularly used cleaning products used in homes and offices are nothing
but disinfectants.

14. Types of Disinfectants
Some common types of disinfectants include:
1.Air disinfectants: It is defined as the chemical substances which are used to kill
the microorganisms that are suspended in the air. It can also be called as a
disinfectant spray.
2.Alcohol: It is seen that alcohols are used as disinfectants. Ethanol is the most
common example in this case. Some other examples of disinfectants are, chlorine
when it is in the concentration of 0.2 to 0.4 in aqueous solution and sulphur dioxide,
which acts as a disinfectant in small concentrations.

15. ANTISEPSIS

16. Types of Antiseptics
 Some antiseptics are germicidal in nature, implying that they have the ability to completely destroy microbes.
 These types of antiseptics are referred to as bacteriocidal antiseptics.
 Other antiseptics only inhibit the growth of microbes (or prevent the growth of microbes altogether).
 Such substances are commonly referred to as bacteriostatic antiseptics.
Antisepsis
 Antiseptics can be defined as antimicrobial agents which can be applied on the
body of living organisms to inhibit the action of microbes.
 They are not injected into the body like the antibiotics, rather they are applied on
the surface of the skin to heal the living tissues in case of wounds and cuts.
 Dettol is the most commonly used antiseptic.
 It is a mixture of chloroxylenol and terpineol.
 Iodoform is also used as an antiseptic for wounds.

17. The Difference between Disinfectants and Antiseptics
Disinfectants and antiseptics are both used for killing the microbes but still, there is a difference between them.
 An antiseptic is used for killing the microbes on the living tissues whereas a disinfectant is applied on a non-living
object.
 Secondly, the concentration of both differ. We can use the same chemical as a disinfectant and an antiseptic by
varying its concentration.
 For example, phenol can be used as an antiseptic if its concentration is 0.2 per cent but to use it as a disinfectant the
concentration should be 1 per cent.
 We can broadly conclude that the cleaning products contain disinfectants and the healing products (for curing the
living tissues) contain antiseptics.
 Both are similar in nature but vary in their concentration. Lysol is a disinfectant whereas Dettol is an antiseptic.