disinfection

1. WEST BENGAL UNIVERSITY OF ANIMAL AND FISHERY SCIENCES
FACULTY OF FISHERY SCIENCES
A SEMINAR ON : DISINFECTANT (AAH – 223)
SUBMITTED TO:
PROF. T. J. ABRAHAM
Dept. Of Aquatic Animal Health
Submitted by:
AGNIVA PRADHAN
B.F.Sc, 2ND YEAR, 2ND SEMESTER
FS No. F/2017/02
Reg. No. 6129 of 2017-18

2. Disinfection
Kill Micro-
organism
Disinfectant is a
chemical substance
Surface of living and non-
living things
Except some
resistant fungal
spores
Sterilization
Less effective
In our day to day life
disinfection process is very
helpful
Disinfectants are antimicrobial agents that are applied to the surface of non-living
objects to destroy microorganisms that are living on the objects. Disinfection does not
necessarily kill all microorganisms, especially resistant bacterial spores.

3. History Related Facts :-
 At the beginning of 20th century there were few drugs available for treatment of
infection.
 Antiseptics and disinfectants had at that stage been employed for various purposes.
 examples being phenol (carbolic acid), mercuric chloride, chlorine, hypochlorite
and iodine.
 Quaternary ammonium compounds (QACs) were described in 1916 but were not
used commercially for another 19 years.
 During the first World War, H.D. Dakin used sodium hypochlorite for open wound
disinfection, saving many soldiers’ limbs and lives.

4. A Commercial Advertisement Of An Disinfectant In 1950
In1950 Disinfectant
was commercialised
publically.

5. Some important properties of disinfectant :-
 It should be non-corrosive, inexpensive and effective.
 It should be a broad spectrum and should not cause deterioration of the
object to which it is applied.
 It should not be harmful to human being and animal.
 It should have a pleasant odour or odourless
 It must be soluble in water and safe for regular use.
 It should not cause any kind of pollution when disposed in open
Environment.
 Fast acting in short contact time.

6. Difference Between Antiseptic and
Disinfectant :-
Antiseptic
 All antiseptics are disinfectants.
 It is applied on living tissue.
 Eg. Skin, Mucus membrane
Disinfectant
 All disinfectants are not antiseptics.
 It is applied on inanimate(non-living)
object.
 Eg. Surface, lab working tables.

7. Classification Of Disinfectants: -
Disinfectant
Physical
agent
Heat Radiation Filteration
Chemical
agent
Alcohol Halogen Biguanide Surface
active
substance
s
Phenol and
Phenolic
compound
s

8. Normal usage of disinfectants
Disinfectant
Bathroom
Floor
Hand
wash
Biological
laboratories
Hospital
Pharmaceutical
Industry
Food
Industry
Dairy
Industry
Brewery
Industry
Kitchen

9. TypeofDisinfectant
Bactericide – kills bacteria
Fungicide – kills fungi
Virucide — kills virus (enveloped/lipophilic are typically easier to kill
than non enveloped viruses)
Sporicide — kill spores (fungi and bacteria)
Biocide — kills living organisms
Bacteriostat — inhibits the
growth of bacteria

10. How Disinfectants works ?
 Physical damage to cell
membrane surface.
 Denaturation of cell
protein and DNA or
Genetic material in
Viruses.
 Inactivation of Enzyme.
 By rupturing cell
membrane and leakage of
cell contents kill the
bacteria.

11. Discussion About The Various Disinfectants
Chemical agent:-
Alcohols- Alcohols have fairly rapid bactericidal action against vegetative
bacteria when diluted to the concentration of 60% to 70% v/v with water.
 Ethanol 60 to 70% v/v and isopropanol 50 to 60% v/v are used as skin
disinfectants while methanol vapour has been used as fungicide.
 The higher alcohols ( propyl, butyl, amyl etc) are more germicidal than ethyl
alcohol.
 Alcohols are used as preservatives in some vaccines.
Aldehyde: -
 Formaldehyde (HCHO) is the main aldehyde used for disinfection.
 Formaldehyde in solution is useful for sterilization of certain instruments.

12. Halogens
 Hypochlorites- Chlorine eliminates both enveloped and non enveloped
viruses. Chlorine also is effective against fungi, bacteria, and algae. Chlorine is
not effective against spores (dose-1-3mg/L)
 Iodine and Iodophor Disinfectants- Iodine and iodophors are simply
chemical compounds. (2-3 litres/ha). This is mainly the egg disinfecting agent.
 Chlorhexidine- Chlorhexidine, a biguanide, is widely used in the US.
Chlorhexidine is relatively nonirritating to tissues. Chlorhexidine, while
considered bactericidal, virucidal and fungicidal, is less effective against these
agents than many other disinfectants.

13. Detergents and soaps
 They are widely used as surface active agents, wetting agents and emulsifiers.
 They are classified into four main groups such as anionic, cationic, non-ionic and
amphoteric.
 The most important antibacterial agents are the cationic surface active agents. Eg:
cetrimide, benzalkonium chloride etc.
 Soaps and sodium lauryl sulfate are anionic compounds. Soaps prepared from
saturated fatty acids are more effective against gram negative bacilli while those
prepared from unsaturated acids have greater action against gram positive.
 Nonionic detergents are not ionized. However these substances do not posses
significant anti-microbial activity.
 Amphoteric compounds have the detergent properties of anionic surfactants
combined with disinfectant properties of cationic surfactants. Eg: Tego compounds.

14.  Oxidizing agent :- Working by reactive oxygen species, the following substances
are basically used: Hydrogen peroxide, ozone and peracetic acid and related
substances. Ozone is only used for water disinfection. The effective dose is 8 ppm
for 3 min. This is used mainly for shrimp hatchery.
Phenolic Disinfectants- Phenols are effective against bacteria (especially gram
positive bacteria) and enveloped viruses. Phenols are not effective against non
enveloped viruses and spores. Phenols maintain their activity in the presence of
organic material and therefore are useful in disinfection of feces. Phenolic
disinfectants may cause skin irritation after prolonged exposure.
 Virkon: - is common disinfectant for aquaculture. 0.5%-1% for 5-10 min is
effective dose

15.  Quaternary Ammonium Compounds- Quaternary ammonium (QA)
disinfectants contain NH4. These are widely used for the control of
microorganisms on floors, walls, nursing homes and other public places.
 They are also used as skin antiseptics and as sanitizing agents in dairy, egg and
fishing industries.
 Dyes :- A number of dyes have been used to inhibit the bacterial growth.
 Basic dyes are more effective bactericides than acidic dyes.
 Acridine and triphenylmethane dyes are commonly used as antimicrobial agents.

16. Physical agent
 The heat treatment is
used to disinfect the
surgical instruments
and others by
autoclave, boiling
(moist heat) or hot air
oven (dry heat).
 The radiation is used
for disinfection, the
radiation destroys the
DNA of infectious
agents.

17. Disinfection of eggs and larvae
 FINFISH-Disinfection of eggs with iodine can be carried out for the
various fish species, but it is most commonly used for eggs of fish of the
Salmonidae family (salmon, trout and char). It mainly prevent some
bacterial contamination (e.g. Renibacterium salmoninarum) and some
viral pathogens (e.g. infectious pancreatic necrosis virus) that may be
present within the eye of newly fertilized egg.
Disinfection of eggs of marine species, such as plaice, cod and Atlantic
halibut are very much common. The disinfection procedure may be
achieved with 400–600 mg/litre of glutaraldehyde and a contact time of 5–
10 minutes. An ozone concentration of 0.1–0.2 mg/L O3 for 3 minutes
inactivates most pathogenic fish bacteria as well.
The primary reasons for disinfecting eggs are to remove fungus and other
disease agents that can affect successful hatching and to clean the eggs for
transport to other locations. Fungi, such as, Saprolegnia sp., and many
bacteria can affect hatching success and are ubiquitous, even in clean
waters

18. DISINFECTION FOR SHELLFISH
 Certain penaeid shrimp, viral diseases (i.e. baculovirosis, and hepatopancreatic
parvovirus infections) are transmitted by faecal contamination of spawned eggs. These
diseases, can be eliminated through the routine use of disinfection protocols when used
to surface disinfect eggs and/or recently hatched nauplii. A widely used method is given
below:
 For fertilised eggs- Collect fertilised eggs. Rinse with running seawater for 1–2 minutes.
Fully immerse eggs in 100 ppm formalin for 1 minute. Fully immerse eggs in iodophore
(0.1 ppm iodine) for 1 minute. Rinse in running seawater 3–5 minutes. Transfer to
disinfected larval rearing tanks.
 For nauplii - Using phototaxic response to light, collect nauplii with netting or screen.
Rinse with running seawater for 1–2 minutes. Fully immerse nauplii in 400 ppm
formalin for 30–60 seconds. Fully immerse nauplii in iodophore (0.1 ppm iodine) for 1
minute. Rinse in running seawater 3–5 minutes. Transfer to disinfected larval rearing
tanks.

19. Factors affecting disinfection process: -
Disinfection
Process
Temperature
Time of contact
pH of
environment
Potentiation, synergism,
and antagonism of
disinfactants
Interfering substances
in the environment
Chemical structure
of disinfectant
Surface
tension Formulation of
disinfectant
Types and number of
micro-organisms present
Concentration of
Disinfectants

20. The Hazards Of Five Commonly Found Disinfectant
chemicals
1. CHLORINE BLEACH: -
 Used to treat drinking water, sanitize swimming pools and to whiten laundry,
and is a strong eye, skin, and respiratory irritant.
 Mixing of chlorine bleach with cleaners like ammonia can release dangerous
chlorine gas.
 Exposure to chlorine gas can cause coughing, shortness of breath, chest pain,
nausea, or other symptoms.
2. AMMONIA: -
 Used in glass cleaners and other hard-surface cleaners, and can be irritating
to the skin, eyes, throat, and lungs.
 Ammonia can burn your skin, and can damage your eyes (including
blindness) upon contact.

21. 3. TRICLOSAN AND TRICLOCARBAN: -
 Daily use of household cleaning products such as hand soap and dish soap as
well as a broad range from toothpaste to socks.
 These chemicals are persistent in the environment, and are linked to hormone
imbalance, and potential increased risk of breast cancer.
4. AMMONIUM QUATERNARY COMPOUNDS (“QUATS”): -
 Found in household cleaning products like disinfectant sprays and toilet cleaners,
 Identified as a known inducer of occupational asthma.
 Certain “QUATS” have also been linked to
 decreased fertility and birth defects in mice.

22. 5. NANO-SILVER: -
 It is incorporated into textiles, plastics,
soaps, packaging, and other materials,
giving each the natural antibacterial
property of silver metal.
 Nano-silver particles can penetrate
deep into your body and have been
shown to be toxic to the liver and brain.

23. Microbial Characteristics and Microbial Control: -
Chemical agent Effectiveness against
Endospores Mycobacteria
Phenolics Poor Good
QUATS None None
Chlorines Fair Fair
Alcohols Poor Good
Glutaraldehyde Fair Good

24. Conclusion: -
 Disinfection has been one of the pre-procedures of most facilities that
are involved in food and health security. The actions of disinfectants
vary as to what disinfectants are used. It can be concluded that the
number of microorganism dead is directly proportional to factors such
as concentration and time. It is therefore concluded that Lysol, alcohol,
bleach, and Iodophor are effective disinfectants. Hand washing is also
necessary to eliminate unwanted microbes in the hands. Furthermore,
species of microbes are also affecting the activity of disinfection as they
differ in the cell composition such as cell wall layer and membranes
and coating contents.

25. Reference: -
 https://en.wikipedia.org/wiki/Disinfectant
 https://www.merriam-webster.com/dictionary/disinfectant
 https://www.nycoproducts.com/.../types-of-disinfectants
 https://ehs.colorado.edu/resources/disinfectants-and-sterilization-methods/
 https://www.slideshare.net/SnehalPatel98/disinfectants-82727464
 https://www.slideshare.net/doctorrao/disinfection
 https://www.slideshare.net/hudamansoor1/disinfectant
 https://www.slideshare.net/Shilpak23/disinfection-65046809
 https://www.youtube.com/results?search_query=disinfection+aimated+cartoon