3. Group Members:
• Saeedullah Khan 6464
• Fazal Abbas 6534
• Mohammad Waqar 6485
• Mohammad Qasim 6528
• M Samar Iqbal 6530
• Hasnain Raza 6462
• Hamza Ahsan 6495
4. Learning Objectives:
• What is Fumigation and Fumigant?
• What are most common fumigants?
• What is the Procedure of Fumigation?
• What are the types of Fumigation methods?
• The Factors affecting fumigation efficacy?
• Advantages and Disadvantages of Fumigation?
5. What is Fumigation?
• Fumigation is the method of disinfecting an
area by completely filling area with gaseous
particles or fumes of certain chemicals to
suffocate or poison the microbes within.
6. Principle of Fumigation:
• Molecules of some fumigants (for instance,
carbon dioxide or inert gases) replace oxygen
molecules in the air.
• So the fumigation involves smothering
(asphyxiation) due to lack of oxygen.
• Other fumigants enter tissues and disrupt
enzymes used in the respiration of microbial
cell.
7. Fumigant:
• A fumigant is a chemical which, at a required
temperature and pressure, can exist as a
vapor or gas that, when released, penetrates
objects or enclosed areas in concentrations
that are lethal to microbial organisms.
8. Fumigant characters to consider:
• Toxicity to the target microbe
• Product’s volatility and penetrating power
• Corrosive effect, flammability, and potential for
explosion
• Warning capabilities and detection methods
• Decomposition time and resulting residues (if
any)
• Availability , Ease of application and Cost.
9. Most Commonly used Fumigants:
• Formaldehyde/Formalin
• Chlorine dioxide
• Hydrogen peroxide
• Incidin plus
• Potassium permanganate
10. Formaldehyde:
• Formaldehyde is a colorless gas
with a pungent odor. Commercial
solutions of formaldehyde in water
are called formalin.
• Fumigation with formaldehyde gas
is performed either by vaporizing
formalin solution or by
depolymerization of solid
paraformaldehyde.
11. Chlorine Dioxide Solution:
• Chlorine dioxide (ClO2) is a
synthetic, green-yellowish gas
with a chlorine-like, irritating
odor.
• Chlorine dioxide is an unstable gas
that dissociates into chlorine gas
(Cl2), oxygen gas (O2) and heat.
• This gas rapidly expands and
penetrates the crevices of the area
to be decontaminated.
12. Hydrogen Peroxide:
• Hydrogen peroxide is a clear,
colorless liquid, and more viscous
than water. It is most commonly
available as a solution in water .
• For laboratory use, 30 wt%
solutions are most common.
• This method is fast, in contrast to
other fumigation techniques, and
does not produce environmentally
harmful end products.
13. Incidin Plus:
• Incidin Plus is an aldehyde free disinfectant
with cleansing activator for surfaces and
fumigation of high risk areas and general areas
with different concentrations for dilutions
which is very economical due to low
concentration i.e. 1%.
It takes only an hour minimum
to disinfect. (ACTIVE
INGREDIENT:- GLUCOPRATAMIN,
a new antimicrobial substance)
14. Potassium permanganate:
• Potassium permanganate is a
purplish-black crystalline salt,
that dissolves in water to give
intensely pink or purple
solutions.
• Potassium permanganate is
widely used in chemical
industry and laboratories as a
strong oxidizing agent and as a
fumigant along with formalin.
15. Fumigation Procedure(general):
• First, the area intended for fumigation is
covered to create a sealed environment.
• Next, the fumigant is released into the space to
be fumigated. The space is held for a set period
while the fumigant gas percolates through the
space and acts on/kills any infestation in the
area.
• Finally, the space is ventilated so that the
poisonous gases are allowed to escape from
the space.
16. Steps Involved:
• But actually, there is a series of steps involved
in fumigation:
1. Pre-Fumigation application
2. Fumigation
3. Post-Fumigation application
17. 1. Pre-Fumigation application:
• Pre-Fumigation application further involves
two steps:
1. Precaution:
• Adequate care must be taken by wearing cap,
mask, foot cover etc.
• Fumigants are mostly irritant to eye & nose. So
the fumigating person must be provided with
the personal protective equipments (PPE).
• Paste a warning notice on the front door
indicating fumigation is in progress.
18. 2. Preparation:
• Close windows and ventilators tightly. If any
openings found seal it with cellophane tape or
other material to avoid the leak of fume.
• Switch off all lights, A/C and other electrical &
electronical items.
• Calculate the room size (surgical theater only)
in cubic feet (L×B×H) and calculate the
required amount of fumigant.
19. 2. Fumigation:
• Fumigation is done through different
fumigants and through different methods.
• Mostly used methods are :
1. Electric Boiler Fumigation method
2. Potassium Permanganate method
20. Electric Boiler Fumigation Method:
• For Each 1000 cubic feet, 500 ml of
formaldehyde (40% solution) added
in 1000 ml of distilled water in an
electric boiler.
• Switch on the boiler, leave the room
and seal the door.
• After 45 minutes ( depending to
volume present in boils apparatus/
its heating proficiency) switch off the
boiler without entering in to room
(Switch off the main from outside).
21. Potassium Permanganate Method:
• In this method, the addition of liquid formalin
to potassium permanganate (KMnO4) in 2:1
ratio (v/w) is done.
• Here the heat generation is induced by
Potassium permanganate (KMnO4), which
generates fume from formaldehyde.
• Take 500 ml of 40%formaldehyde in 1000 ml
of distilled water and then add 250gm of
KMnO4 for 1000 cubic feet of theater.
• After the initiation of formaldehyde vapor,
immediately leave the room and seal it for at
least 12 to 24 hours.
22. 3. Post-Fumigation Application:
• Post -fumigation Application involves 3 processes:
1. Neutralization:
• Before neutralization, formaldehyde fumigation
system should be taken out from surgical
theater.
• Then the toxicity of formaldehyde vapor should
be neutralized with ammonia solution.
• Place a cotton ball and pour 300 ml of 10%
ammonia for each 500 ml of formaldehyde used.
23. 2. Aeration/Ventilation:
• Aerate the fumigated structure before
allowing anyone to enter.
• Use gas detection devices to measure
gas/ vapours concentration.
3. Warning Notice:
• Danger signs must be posted at the
ground level on all doors or entrances.
• The signs must be printed in indelible
red ink on a white background.
24. Factors affecting Fumigation efficacy:
• Sealing the structure
• Concentration and time
• Temperature
• Humidity/Moisture
• Diffusion
• Air Movement
• Susceptibility to fumigant
25. 1. Sealing the structure:
• Proper sealing is most important step in a
fumigation. The more tightly sealed the
structure, the more efficient the fumigation.
• So ,before fumigation, inspect the structure to
be fumigated to determine if it can be made
sufficiently tight.
• Sealing techniques can include polyethylene
sheeting, adhesive tapes and adhesive sprays.
26. 2. Concentration and Time:
• Understanding the relationship of fumigant
concentration, exposure time, and temperature
during fumigation is critical for determining
the proper dosage of fumigant.
• dosage of the fumigant is calculated by the “CT
concept” as follows:
Dosage (D) = Concentration (C) × Time (T)
or
D = C × T (CT)
27. Continued…
• The units for C = grams (g) of fumigant/ cubic
meter (m3)
• The unit for T = hours (hrs)
• Therefore, CT is the product of Concentration(C)
and exposure Time (T) expressed as g-hrs/m3.
• If you increase the exposure time, less gas will be
required to achieve the dosage level (CT) for
control and vice versa.
28. 3. Temperature:
• Temperature has a major impact on fumigant
performance. Poor microbial control may
result if the fumigation is done outside of the
optimal range (60°F to 90°F).
• Fumigants vaporize and diffuse more slowly at
low temperatures .
• In contrast, fumigants vaporize faster and
dissipate more quickly at high temperatures.
29. 4. Humidity/Moisture:
• Moisture affects fumigant penetration.
• Commodities/structures with higher moisture
content require higher doses of fumigant.
• Some fumigants need humidity to generate
gas. If the air is too dry or the moisture content
is too low, these “moisture-activated”
fumigants may not react completely.
• Some fumigants need zero humidity or dry air
to generate fumes like hydrogen peroxide.
30. 5. Air Movement:
• Some air movement is essential for effective
fumigation.
• The gas must spread evenly and quickly
throughout the commodity or space being
treated.
• It must enter small crevices, cracks or spaces
so that a lethal concentration contacts every
microbe.
• This even distribution is called equilibrium.
31. 6. Susceptibility to fumigant:
• Susceptibility to fumigants depends on microbe
species, its type and stage of development, and
its behavior.
• In addition, the way a fumigant is applied can
sometimes influence microbes‘ susceptibility.
• Some microbes may be sensitive, weakly
resistant, or strongly resistant to a specific
fumigant.
32. Advantages of Fumigation:
• Efficient and time-saving technique.
• Fumigants are usually quick acting and can result
in total eradication of the microbe or pest.
• Fumigants diffuse through all parts of the structure
being treated and can reach microbes that cannot
be reached with conventional disinfecting techs.
• Leave no unsightly, odorous, or hazardous residues
if the site is aerated properly.
33. Disadvantages of Fumigation:
• Fumigation requires extra supervision.
• Fumigants are highly toxic to most living
things, including humans. Breathing even
small amounts of some fumigants can be fatal.
• Some fumigating products are corrosive or
flammable.
• Leaks can allow fumigant concentration to
drop below lethal levels before the
required exposure period has elapsed.
