2. Presentation outline
• Learning objectives
• Introduction
• Chemical Disinfectants
• Decontamination
• Cleaning
• Sterilization and storage
• High level disinfection and storage
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3. Learning objectives
• At the end of this module, participants will be able to:
– Describe the steps of instruments and other items processing
– list commonly used disinfectants
– Explain how disinfectant solutions are prepared
– Demonstrate the steps of decontamination process, cleaning
process, sterilization and HLD process
– Explain how to store sterilized and high level disinfected
instrument and other items
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4. Introduction
• Every item, whether a soiled metal instruments or pair of
surgical gloves, requires special handling and processing in order
to:
– Minimize the risk of accidental injury or blood or body fluid exposure to
cleaning and housekeeping staff; and
– Provide a high quality end product (i.e., sterile or HLD instruments and
other items).
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6. Chemical Disinfectant
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Disinfectants are chemicals that destroy or inactivate
microorganisms on inanimate objects
They are not meant to be used on the skin or mucus
membranes
7. Chlorine and chlorine releasing compounds
1. Sodium Hyporchlorite (chlorine bleach)
– Advantages
• It is the least expensive and most readily available
• Easy to prepare and use.
• Quickly inactivates all viruses as well as killing tubercle bacillus.
• Very useful for decontaminating soiled surgical instruments, gloves and
other items and large surface areas.
– Limitation
• Inactivated by organic matter.
• Loses potency on standing if left in open container (replace at least daily).
• May corrode metal instruments with prolonged exposure (>20 minutes) to
concentrations greater than 0.5%.
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8. Chlorine … cont’d
2. Calcium hypochlorite or chlorinated lime
– Available in powder form.
– Calcium hypochlorite contains approximately 70% available
chlorine.
– Chlorinated lime contains approximately 35% available
chlorine.
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9. Chlorine …continued
• Advantages
– Both decompose more slowly than sodium hypochlorite, but
they still should be protected by storing away from heat and
light.
• Limitation
– Inactivated by organic matter.
– May corrode metal with prolonged exposure (>10 minutes)
unless thoroughly rinsed.
– More difficult to prepare dilute solutions due to poor
solubility in alkaline water (PH >8)
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10. 3. Formaldehyde
• It can be used as a chemical sterilant, as well as a high-level
disinfectant.
• However have the following limitations
– Causes skin irritation.
– Potential carcinogen
– Irritates the skin, eyes and respiratory tract, even at low
concentrations.
– Produces a dangerous gas (bis-chloromethyl-ether) when mixed
with chlorine.
• There fore, should not be used for HLD or sterilization if
other high-level disinfectants are readily available.
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11. 4. Glutaraldehydes
• An alkaline-stabilized 2% glutaraldehyde available commercially as Cidex® or Cidex 7®
are the most common
• Advantages
– Not readily inactivated by organic materials.
– Generally can be used for up to 14–28 days.
– Noncorrosive and can safely be used on surgical endoscopes
(laparoscopes)
• Limitation
– Can cause skin irritation or dermatitis with chronic exposure.
– Vapors are irritating to mucous membranes (eye, nose and mouth)
and respiratory tract.
– Work best at room temperature (20–25oC or 68–77oF).
– Expensive.
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12. Preventing Contamination of Disinfectants
• Pour solutions into smaller container for use during service
delivery to avoid contaminating the stock container.
• Label reusable containers with the date each time they are
washed, dried and refilled.
• Always use clean water for decontamination, boiled water for
HLD and sterile water for sterilization to dilute disinfectants.
• Prepare and use disinfectant in a clean, less traffic flow and
duty area.
• Store disinfectants in a cool, dark area. Avoid storing them in
direct light or excessive heat, as this may reduce their
strength.
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13. Household Bleach Safety
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• Use mask, goggles, rubber gloves,
waterproof apron and cape
• Mix in well-ventilated and at room
temperature
• Do not use or mix with other detergents
• Use cold water to mix
15. What is decontamination?
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• Decontamination is the process of making inanimate
objects safer to handled by staff before cleaning.
o Inactivates HBV and HIV
o Must be done before cleaning
o It is done by soaking the equipment in 0.5% chlorine solution
16. Instructions for Preparing Dilute Chlorine Solutions
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To make a 0.5% chlorine solution from 5% bleach, mix 1 part
bleach to 9 parts water.
Dilute
%
e
Concentrat
%
Total parts (TP) (H2O) = - 1
Total parts (TP) (H2O) =
Dilute
.5%
e
Concentrat
5%
- 1 = 9 Total parts (TP) (H2O)
17. 17
Examples Using 5% Bleach for
0.5% Concentration
One part bleach to 9 parts water (use the same container to measure
the bleach and water)
18. Instructions for Preparing a Chlorine Solution from a
Powder
18
To make a 0.5% chlorine solution from
a 35% chlorine powder,
mix 14.2 grams of powder to 1 liter of water.
e
Concentrat
%
Dilute
%
Gram/Liter = X 1000
e
Concentrat
35%
Dilute
.5%
Gram/Liter = X 1000 = 14.2 Gram/Liter
19. Decontamination practices
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• Place instruments and reusable gloves in 0.5%
chlorine solution after use
• Soak for 10 minutes and rinse immediately.
• Do not soak instruments in decontaminating solution
for more than 10 minutes, because it results corrosion
• Use plastic container with cover for decontamination
• Wipe surfaces (exam tables) with chlorine solution
• Flush syringe and needles with 0.5% chlorine solution
20. Use three buckets, one filled with 0.5% chlorine solution, one with soap and water and one
with water
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22. labeling of the containers is one of the important aspects of
decontamination
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23. Cleaning
• Physically removing infectious agents and other organic
matters
– Method of mechanically reducing the number of
microorganisms, especially endospores
• Doesn’t necessarily destroying infectious agents
• Is an essential pre- requisite to ensure effective
disinfection or sterilization
• Use liquid soap for effective cleaning
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24. Cleaning
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Cleaning practices
• Use PPE during cleaning
• Disassemble instruments
• Wash with detergent, water, and a
soft brush.
• Scrub instruments under the water
surface until visibly clean.
• Thoroughly rinse with clean water.
25. Sterilization and Storage
• Sterilization
– Destroys all microorganisms, including endospores
– Used for instruments and other items that come in direct
contact with the blood stream or tissue under the skin
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26. Common Methods of Sterilization
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High-Pressure Steam (Autoclave) Chemical
Dry-heat (Oven)
27. High-Pressure Steam Sterilization (Autoclave)
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• Principles:
– Steam, especially under pressure, carries thermal energy.
– The protective outer layer of the microorganisms can be softened
by the steam, allowing coagulation.
– Certain contaminants, such as grease or oil materials, can protect
microorganisms against the effects of steam.
• Requirements:
– Adequate contact
– Sufficiently high temperature
– Correct time
– Sufficient moisture
28. Autoclave … Continued
• The temperature, pressure and time combination for steam
sterilization is:
• 121°C (250ºF); 106 kPa (15 lbs/in2) pressure:
o 20 minutes for unwrapped items
o 30 minutes for wrapped items
• 1320C (2700F), pressure of 30lbs/in2 for 15 minutes for wrapped
items.
• Allow all items to dry before removing.
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29. Autoclave…continued
• Sterilization depends on correctly following certain
practices and processes including:
– Routine maintenance
– Preparing items to be sterilized
– Packing and wrapping
– Operating
– Unloading the sterilizer
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32. • Instructions for operating steam sterilizer
– Decontaminate, clean, and dry all instruments and other
items to be sterilized.
– All jointed instruments should be in an open or unlocked
position; when possible, instruments should be disassembled.
– Instruments should not be held tightly together by rubber
bands. Allow free circulation and penetration of steam to all
surfaces.
– Wrap instruments in double thickness of muslin or
newspaper.
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33. Autoclave…continued
• Instructions for operating steam sterilizer
– Allow instrument packs to dry completely before removal.
Wet packs act like a wick, drawing in bacteria, viruses, and
fungi from the environment.
– Wrapped instrument packs are considered unacceptable if
there are water droplets or visible moisture on the package
exterior when removed from the autoclave.
– Place sterile trays and packs on a surface padded with paper
or fabric, away from windows or fans.
– Wrapped items remain sterile as long as the pack remains
clean, dry (including no water stain), and intact.
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34. Dry Heat Sterilization (Oven)
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• Principles:
– Dry heat sterilization is accomplished by thermal (heat) conduction.
– Initially, heat is absorbed by the exterior surface of an item and then passed to the
next layer.
– Microorganisms die as their proteins are slowly destroyed.
– Dry heat sterilization takes longer time than steam sterilization because the steam
speeds up the penetration of the heat.
• Requirements:
– Adequate temperature
– Correct time
35. Oven…cont’d
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Recommended temperature/time ratios
170°C (340°F) 60 minutes
160°C (320°F) 120 minutes
150°C (300°F) 150 minutes
140°C (285°F) 180 minutes
121°C (250°F) overnight
Remember: Depending on the temperature selected, the total cycle time
(preheating, sterilization time, and cool down) will range from about 2.5 hours
at 170°C to more than 8 hours at 121°C.
36. Oven
• Instructions for dry heat oven
• Decontaminate, clean, and dry all instruments and other
items to be sterilized.
• Items can be wrapped in aluminum foil or placed in a metal
container with a tight-fitting lid. Wrapping helps prevent
recontamination prior to use.
• Place loose (unwrapped) instruments in metal containers or
on trays in the oven and heat to desired temperature.
• Begin timing after the desired temperature is reached
• Items should be removed and stored after cooling.
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37. Chemical Sterilization
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• It is an alternative for items that would be damaged if subjected
to steam or dry heat sterilization.
• Glutaraldehyde and formaldehyde are sterilants if used for the
appropriate time.
• Glutaraldehyde and formaldehyde are not readily inactivated by
organic materials.
• When handling these products:
o Wear gloves to avoid skin contact.
o Wear protective eyewear to protect from splashes.
o Limit exposure time.
o Be in a well-ventilated area.
39. Instructions for Chemical Sterilization
• Decontaminate, clean, and dry all instruments and other
items to be sterilized.
• Completely submerge the items in a clean container filled
with the chemical solution and place the lid on the
container.
• Allow items to soak
– 10 hours in glutaradehyde or
– 24 hours in formaldehyde.
• Remove objects from the solution with sterile forceps, rinse
all surfaces three times with sterile water, and air-dry.
• Store objects in a sterile container with a tight-fitting lid.
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40. Monitoring Sterilization Procedures
• Sterilization procedures can be monitored routinely
using:
– Biological indicators:
– Mechanical indicators:
– Chemical indicators:
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43. Storage of a Sterile Package
• All sterile items should be stored in an area whereby the
packs or containers will be protected from dirt, moisture
and animals.
• As long as the sterile pack remains dry and intact , the
shelf life of the item could stay till one moth
• The storage area is best located next to or connected to
the place where sterilization occurs
• It should be in a separated enclosed area with limited
access that is used only to store sterile and patient care
supplies.
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46. The Shelf-Life System
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• The shelf-life of an item after sterilization is event-related.
• The item remains sterile until something causes the package to
become contaminated.
• An event can be:
o A tear or worn area in the wrapping
o The package’s becoming wet
o Anything that will enable microorganisms to enter the package or
container
• These events can occur at any time
47. The Shelf-Life of a sterilized Object
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Shelf-life depends on the following factors:
• Quality of the wrapper or container
• Number of times a package is handled before use
• Number of people who handled the package
• Status of package storage of in an open or closed shelves
• Condition of the storage area (humidity, cleanliness)
• Use of plastic dust covers and method of sealing
48. High-Level Disinfection
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Principles:
• Destroys all microorganisms including HBV, HCV, and
HIV; does not reliably kill all bacterial endospores
• Only acceptable alternative when sterilization
equipment is not available
50. HLD…Cont’d
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Practices of HLD by Boiling
• Boil instruments for 20 minutes.
• Always boil instruments in a pot with
a lid.
• Start timing when the water begins
to boil.
• Do not add anything to the pot after
timing begins.
• Air-dry before use or storage.
51. HLD… continued
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Practices of HLD by Steaming
• Steam for 20 minutes.
• Be sure there is enough water in the bottom pan for the entire
steam cycle.
• Bring water to a rolling boil.
• Start timing when the steam begins to come out from under the
lid,
• Do not add anything to the pan after timing starts.
• Air-dry and store instruments in covered steamer pans.
53. HLD…continued
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Practices for Chemical High-Level Disinfection
• For HLD, a 0.1% chlorine solution shall be prepared
from boiled water
• Decontaminate, clean, rinse and dry instruments,
• Cover all items completely with disinfectant,
• Soak for 20 minutes,
• Rinse thoroughly with boiled water three times,
• Air-dry before use and storage,
• Remove items using HLD or sterile forceps/gloves
55. Chemicals used for HLD
1. Chlorine solution 0.1%
– Safe for stainless and plated instruments
– Concentrated solutions >0.5% can corrode metals
2. Formaldehyde 8%
– Vapors are irritating (staff should wear appropriate PPE)
– A potential carcinogen
– Do not mix with chlorine
• can produce dangerous gas
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56. Chemicals used for HLD … continued
1. Glutaraldehyde 2-4%
– Less irritating but still needs to be in well ventilated area
2. Hydrogen peroxide 6%
– Highly corrosive
– should not be used to disinfect:
• copper, aluminum and zinc
– Loses potency rapidly when exposed to heat and light,
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58. Effectiveness of Methods for
Processing Instruments
Method Effectiveness (kill or
remove microorganisms)
End Point
Decontamination Kills HBV and HIV and most
microorganisms
10-minute soak
Cleaning (water only) Up to 50% Until visibly clean
Cleaning (water and soap) Up to 80% Until visibly clean
Sterilization 100% High-pressure steam, dry heat, or
chemical
High-Level Disinfection 95% (does not inactivate some
endospores)
Boiling, steaming, or chemical for 20
minutes
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59. Guidelines for which Process to Use
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Procedure Sterilization HLD
Cesarean Section Preferred Acceptable
Abdominal Laparotomy Preferred Acceptable
Vaginal Childbirth Preferred Acceptable
Contraceptive Implants Preferred Acceptable
Laparoscopy Preferred (chemical only) Acceptable
MVA Cannulae1 Acceptable Acceptable
IUD (insert/remove) Acceptable Acceptable
Pelvic Examination Acceptable Acceptable
1 MVA: manual vacuum aspiration (for treatment of incomplete abortion)