The document discusses various methods and processes for decontaminating medical equipment. It defines key terms like contamination, decontamination, cleaning, drying, disinfection and sterilization. It describes the three levels of risk for medical equipment based on its contact with patients - high, medium and low risk. For each level, it recommends the appropriate decontamination process - sterilization for high risk equipment, sterilization or disinfection for medium risk, and cleaning for low risk. It then discusses the various processes in detail, including manual and automated cleaning methods, types of disinfectants and disinfection methods, and sterilization techniques like heat, radiation and filtration.

1. TOPIC :BARRIER NURSING[Decontamination of
equipments and unit ]
Prepared By:Mrs BeminaJA
Assistant Professor
ESIC College of Nursing
Kalaburagi

2. In order to ensure safe systems of work and to prevent
transmission of infection, it is essential that
decontamination of equipment after use on a patient is
undertaken to prevent the transmission of infection.
This is in accordance with the requirements of the Health
and Social Care Act 2008: Code of Practice on the
prevention and control of infections and related
guidance.

3. Contamination: The soiling of an object with harmful,
potentially infectious or unwanted matter.
Decontamination: A combination of processes that
removes or destroys contamination.
Consequently micro-organisms (or other contaminants)
are prevented from reaching a susceptible site, in
sufficient numbers necessary to initiate infection or any
harmful response.

4. These are the process to be followed to initiate correct steps in performing
decontamination:
CLEANING:
Physical removal of contaminants including dust, soil and organic matter , along with
a large proportion of micro organisms.
Detergent wipes or detergent and warm water and single use cloths are recommended.
• Cleaning is essential before disinfection or sterilisation is carried out.
• All equipment that has been cleaned must be dried thoroughly before storage.
DRYING
Drying with a large proportion of micro organisms. Drying will cause a further
reduction. This Process is essential prior to disinfection and Sterilization.
DISINFECTION:
Utilizing heat or chemicals to reduce the number of viable micro- organisms to a level
which is not harmful to health (but not all viruses and/or bacterial spores).
STERILIZATION:
Renders the object free from viable micro-organisms, including viable micro-
organisms, including bacterial spores and viruses.
Important Note:
 All decontamination procedures should be undertaken by a qualified trained and
equipped member of staff, wearing personal protective equipment.

5.  Each instrument or piece of medical equipment which
comes into contact with a patient is a potential source
of infection.
 The decontamination process required is commonly
specified as one of three levels (based on the
classification system first proposed by Dr E H
Spaulding).
These are divided into 3 groups of risk:
 High risk/Critical Item
 Medium risk/ Semi critical Item
 Low risk/ Non Critical Item

6. RISK Application Recommendati
on
High Item in close contact with a break in the skin or mucous
membrane or introduced into a sterile body cavity or
tissue.
Critical items must be sterile.
Some are: Surgical instruments Cardiac or IV or
Catheters
Sterilization
Medium Item in contact with nonintact mucous membranes or
skin, body fluids and particularly after use on infected
patients or prior to use on immuno- compromised
patients.
These items must be free of all microorganisms (except
spores)
Sterilization or
Disinfection
Low Items in contact with healthy/intact skin but not mucous
membranes or not in contact with patient.
Item must be clean. Some are: Bedpans Linens
Stethoscope
Disinfection or
Cleaning

7. Method Selection
Various factors influence the choice of decontamination process:
 1)Nature of organisms present: The CDC recommends that all
supplies, linens, and equipment in a health care setting should be
treated as if the patient were infectious.
 2)Number of organisms present: The more organisms present on
an item, the longer it takes to destroy them.
 3) Type of equipments: Equipment with small lumens, crevices,
or joints requires special care. Articles which are prone to
damage during decontamination requires special attention.
 4) Intended use of equipment: The need for medical and surgical
asepsis influences the preparation and cleaning of equipment.
 5) Available means for sterilization and disinfection: The choice
of method depends on the availability and practicality of the
means.
 6) Time: Time is a key factor when sterilizing or disinfecting
articles. Failure to follow the recommended time periods is
grossly negligent.

9.  Definition
CLEANING is a dirt removing process, using liquid detergent and
warm water. This process removes a high proportion of all micro-
organisms.
 It is essential for the removal of organic matter, grease and lubricants,
which might otherwise protect organisms from additional
decontamination processes such as disinfection and sterilization
General principles:
 Cleaning and thorough rinsing should always precede any attempt to
disinfect or sterilize.
 Cleaning can be achieved by either manual or automated methods.
 Cleaning should be carried out using a validated cleaning process
wherever possible.

10. Types of Cleaning
1) Manual Cleaning
2) Automated Cleaning
Effective cleaning is an essential prerequisite to all subsequent methods of
decontamination.
Manual cleaning is an implementation of cleaning process done by human.
Automated cleaning is a controlled process that will provide more consistent
results and therefore manual cleaning of items should only be undertaken when
automated methods are inappropriate or unavailable.
List of automated cleaners
Ultrasonic cleaner – Ultrasonic cleaning is a process that uses ultrasound
(usually from 20–400 kHz) and an appropriate cleaning solvent (sometimes
ordinary tap water) to clean items.
Washer disinfector - systems that are designed to clean and disinfect specific
medical utensils, surgical instruments and other articles found in healthcare
facilities.
Thermal washer disinfector - The use of an automated thermal washer-
disinfector provides disinfection using moist heat.
Thermal disinfection takes place at 93°C with a temperature holding time in
compliance.
This process incorporates both cleaning and disinfection.

12.  Disinfection is the killing of many, but not all microorganisms. It
is a process of reduction of number of contaminating organisms
to a level that cannot cause infection, i.e. pathogens must be
killed. Some organisms and bacterial spores may survive.
 Disinfectants are chemicals that are used for disinfection.
Disinfectants should be used only on inanimate objects.
 Antiseptics are mild forms of disinfectants that are used
externally on living tissues to kill microorganisms, e.g. on the
surface of
 Disinfection Used when items cannot be sterilized or situations
where no method of sterilization is available.
 Chemicals used in disinfection are called disinfectants.
 Different disinfectants have different target ranges, not all
disinfectants can kill all microorganisms.

13. Importance of disinfection:
 The method of disinfection is used internationally for
the safety of humans, to decrease the scale of
transmission of diseases.
 A large emphasis of sterilization and disinfection has
been placed in the food industry, water sanitization and
medical care and hospitals.

14.  Number and Location of Microorganisms:
 Innate Resistance of Microorganisms:
 Concentration and Potency of Disinfectants:
 Physical and Chemical Factors:
Several physical and chemical factors also influence
disinfectant procedures: temperature, pH, relative
humidity, and water hardness.
 Organic and Inorganic Matter:
 Duration of Exposure:
 Biofilms: Microorganisms may be protected from disinfectants by
production of thick masses of cells and extracellular materials, or
bio films. Once these masses form, microbes within them can be
resistant to disinfectants by multiple mechanisms, including
physical characteristics of older bio films, genotypic variation of the
bacteria, microbial production of neutralizing enzymes, and
physiologic gradients within the bio film (e.g., pH).
 Porous or smooth:

15. Consistency
• Liquid (Alcohols, Phenols)
• Gaseous (Formaldehyde vapour, Ethylene oxide)
Spectrum of activity
• High level
• Intermediate level
• Low level
Mechanism of action
• Action on membrane (Alcohol, detergent)
• Denaturation of cellular proteins (Alcohol, Phenol)
• Oxidation of essential sulfhydryl groups of enzymes (H2O2,
Halogens)
• Alkylation of amino-, carboxyl- and hydroxyl group (Ethylene
Oxide, Formaldehyde)

16.  Low – Level Disinfectants For Housekeeping And Non – Critical
Items That Does Not Touch The Patient’s Skin Ex. Lysol alcohol-
free quaternary ammonium compound.
 Intermediate Level Disinfectants For Semi – Critical Items That
Comes In Contact With The Skin
 Ex. water-based phenolics, alcohol-based phenolics, iodophors, sodium
hypochlorites and other chlorine compounds, and alcohol-based
quaternary ammonium compounds.
 High Level Disinfectant For Critical Items That Comes In Contact
With The Body Tissues Or Below Skin Membranes
 Peracetic acid.
 Hydrogen peroxide.
 Glutaraldehyde.
 Hypochlorous acid.
 Hypochlorite.
 Ortho-Phthaldehyde.

17.  PHYSICAL DISINFECTION:
 Disinfection is best achieved by moist heat such as boiling
in water (100°C for 10 minutes at sea level) or by
Tindilization means boiling for 20 minutes and then
cooling, again re-boiling and cooling for three times which
kills all organisms except for a few bacterial spores.
 PHYSICAL DISINFECTANT
BOILING WATER
PASTERURIZATION
ULTRAVIOLET RAYS
The Rays Comes In Contact With The Organisms Wear
Protective Skin Covering!!!Skin Covering!!!

18. CHEMICAL DISINFECTION:
Chemical disinfectants may be supplied ready to use or may need accurate
dilution to use
 Liquid disinfectants are preferably used for solid surfaces and equipment. They
vary greatly in their efficiency, depending on the chemical constituents and the
agents involved.
 These include alcohols, chlorine and chlorine compounds, formaldehyde,
glutaraldehyde, ortho-phthalaldehyde, hydrogen peroxide, iodophors, peracetic
acid, phenolics, and quaternary ammonium compounds. Chemical disinfection
may only be used for items for which thermal disinfection
 Chemical Disinfectant Solutions
 Phenol and Phenol Derivatives:
 concentrations 5% to 10 %.
 Unpleasant odor
 Toxic
 used for disinfection of walls, floors, bench tops.
 They effectively kill bacteria including Mycobacterium tuberculosis, fungi and
lipid- containing viruses.
 They are not active against spores

19.  Halogens (Chlorine and Iodine):
Sodium hypochlorite is the most common
Common household bleach (5% available chlorine) can be
diluted 1/10 to 1/100 with water
At high concentrations and extended contact time, considered
cold sterilants
They are most often used as antiseptics and in surgical soaps
and are relatively nontoxic to humans.
 Alcohols
Ethyl or isopropyl alcohol in concentration of 70% to 90% are
good general-use disinfectants.
they evaporate fast and therefore have limited exposure time.
They are less active against non- lipid viruses and ineffective
against lipid viruses and ineffective against bacterial spores.
Concentrations above 90% are less effective. They should only
be used after all the visible surface dirt has been removed from
the area to be disinfected.

20.  Aldehydes
Formalin is 37% solution of formaldehyde in water.
Dilution of formalin to 5% results in an effective
disinfectant.
Formaldehyde is a human carcinogen and creates
respiratory problems at low levels of concentration.
 Glutaraldehyde:
Chemically related to formaldehyde, is more effective
against all types of bacteria, fungi, and of bacteria,
fungi, and viruses.
Vapors of glutaraldehydes are irritating to the eyes
nasal passages and upper nasal passages and upper
respiratory tract.

21.  Quaternary Ammonium Compounds (Quats):
Detergents with strong surface activity.
They are active against Gram-positive bacteria
They are less active against Gram-negative bacteria .
Quats are relatively nontoxic and can be used for
decontamination of food equipment and for general
cleaning.
 Hydrogen Peroxide
3% Hydrogen peroxide is stable and efficient against
inanimate surfaces.
Peroxides are often used as antiseptics in cleaning in
wounds.
The activity is highest against anaerobic bacteria.
It can cause damage to tissues and cause delay in healing.

22.  Sterilization is the killing or removal of all microorganisms, including
bacterial spores which are highly resistant.
 Sterilization is an absolute term, i.e. the article must be sterile meaning the
absence of all microorganisms.
 Sterilization destroys all microorganisms on the surface of an article or in a
fluid to prevent disease transmission associated with the use of that item.
 While the use of inadequately sterilized critical items represents a high risk of
transmitting pathogens.
USES OF STERILIZATION
1. Sterilization for Surgical Procedures: Gloves, aprons, surgical
instruments, syringes etc. are to be sterilized.
2. Sterilization in Microbiological works like preparation of culture media,
reagents and equipments where a sterile condition is to be maintained.
 Commonly Used In The Operating Room And Delivery Room
 Nursing Procedures That Are Invasive

23. Purpose
 Eliminate All Microorganisms That Will Come Into
Contact With Body Tissues.
 Protect Patients From Possible Infection When Natural
Defenses Are Not Normal
 Procedures Requiring Sterile Technique
 Procedures When Underlying Tissues Are Being
Exposed tissues
 Internal Body Areas Are Normally Sterile

24.  PHYSICAL AGENTS
Thermal/Heat
Ionizing Radiation
Filtration
 CHEMICAL AGENTS

25.  Sterilization By Heat
 Heat is most effective and a rapid method of sterilization and disinfection.
 Excessive heat acts by coagulation of cell proteins. Less heat interferes with
metabolic reactions.
 TYPES OF HEAT:
 A. Sterilization by moist heat
 B. Sterilization by dry heat
A. Sterilization by moist heat Moist heat acts by denaturation and coagulation of
protein, breakage of DNA strands, and loss of functional integrity of cell
membrane.
(I) Sterilization at 100°C
(II) Sterilization above 100°C
(III) Sterilization below 100°C
Sterilization at 100°C
1. Boiling: Boiling at 100°C for 30 minutes is done in a water bath. Syringes,
rubber goods and surgical instruments may be sterilized by this method.
2. Steaming: Steam (100°C) is more effective than dry heat at the same
temperature. It is done with a steam sterilizer. In this sterilization is done by
two methods:
a) Single Exposure for 11/2 hours
b) Tyndallization (Fractional Sterilization)

26. (II) Sterilization above 100°C:
Autoclaving It is one of the most common methods. It is a metallic cylindrical vessel.
It is done by steam under pressure.
When the autoclave is closed and water starts boiling above 100°C and
(III) Sterilization below 100°C
1. Pasteurization: Pasteurization is heating of milk to such temperature and for such a
period of time so as to kill pathogenic bacteria that may be present in milk without
changing color, flavor and nutritive value of milk.
i) Flash Method: Heating at 72 °C for 15 secs.
ii) Holding Method: Heating between 63 °C and 66 °C for 30 minutes
2. Inspissations: stiffening of protein without coagulation between 70 °C to 80 °C
STERILIZATION BY DRY HEAT MECHANISMS
By protein denaturation, oxidative damage and toxic effect of elevated electrolyte.
Dry heat at 160 °C holding for one hour.
1. Red Heat: heating to red in Bunsen burner or spirit lamp flame.
2. Flaming: the article is passed through flame without allowing it to become red hot.
3. Incineration : ignites and reduce to ash & gas 4. Hot air oven (sterilizer): one of the
most

29. Sterilization By Radiation
 Gamma and X-ray are two principal types of ionizing
radiation used in sterilization.
 Their application is mainly centered on the sterilization
of prepackaged medical devices.
 Ultraviolet (UV) radiation is a practical method for
inactivating viruses, mycoplasma, bacteria and fungi.
 UV radiation is successfully used in the destruction of
airborne microorganisms.
 UV light sterilizing capabilities are limited on surfaces
because of its lack of penetrating power .

30.  Ionizing Radiation
 Exposure To Irradiation
 Irradiation Sterilization Is Suitable For Heat And
Moisture Sensitive Items
 Sterilization By Filtration Sterilize solutions which are
heat liable such as sugar solutions, sera and antibiotics
are done by filtration methods.
Types:
 1. Earthen ware (Candle) filter
 2. Asbestos (seitz) disc filters
 3. Membrane filter
 4. Syringe filter
 5. Air filters

31. Chemical Agents
Chemicals are also used for sterilization. Heating provides a reliable way to rid
objects of all transmissible agents, but it is not always appropriate if it will
damage heat-sensitive materials such as biological materials, fiber optics,
electronics, and many plastics. In these situations chemicals, either as gases or
in liquid form, can be used as sterilants.
ETHYLENE OXIDE GAS : Is one of the common methods used to sterilize,
pasteurize, or disinfect items because of its wide range of material
compatibility.
ITEMS THAT ARE SENSITIVE HEAT/ITEMS THAT ARE SENSITIVE
HEAT/ MOISTURE.MOISTURE.
HIGHLY FLAMMABLE!!! MONITOR!!!
Ethylene oxide is a colorless gas which is toxic to inhale.
It is effective against all organisms and does not damage equipment.
Ethylene oxide treatment is generally carried out between 30 °C and 60 °C with
relative humidity above 30% and a gas concentration between 200 and 800
mg/l.
Typically, the process lasts for several hours.
Ethylene oxide is highly effective, as it penetrates all porous materials, and it
can penetrate through some plastic materials and films.
The operating cycle ranges from 2 - 24 hours so the turnaround time is
prolonged and it is a relatively expensive process.

32. HYDROGEN PEROXIDE: SAFE AND NON-TOXIC
 Hydrogen peroxide, in both liquid and as vaporized hydrogen peroxide (VHP), is another chemical
sterilizing agent.
 Hydrogen peroxide is used to sterilize heat or temperature sensitive articles such as rigid
endoscopes.
 In medical sterilization hydrogen peroxide is used at higher concentrations, ranging from around
35% up to 90%.
 The biggest advantage of hydrogen peroxide as a sterilant is the short cycle time.
 It have a cycle time as short as 28 minutes.
Ozone Gas
Expensive And Easy To Operate expensive And Easy To Operate Corrosive!!!
Not Used For Items Made Of not Used For Items Made Of Steel Brass And Aluminum steel Brass
And Aluminum
 Liquid Chemical Sterilant
Peracetic Acid: (0.2%) Is A Recognized Sterilant By The FDA For Use In Sterilizing Medical
Devices Such As Endoscopes.
 Liquid Sterilant
 Suitable For Sterilizing Heat
 Rinse In Sterile Water Before
 Can Be Used Immediately
 Indicators Of Sterility
 Sterile Tapes sterile Tapes
 Package With Sterile Indicators
 Expiration Date

33. GENERAL PRINCIPLES
 1. Microorganisms move through space in air currents.
 2. Microorganisms are one transferred from one surface to
another when a non sterile object touches other objects
 3. Microorganism move from one object to another as as a
result of gravity
 4. Microorganisms travel rapidly along any moisture through
a wicking action
 5. Microorganisms move slowly along a dry surface
 6. Microorganisms are releases through the air on droplet
nuclei whenever a person breathes or speaks
 7. Microorganisms are in constant motion in a variety of ways
 8. The edge of the sterile field is potentially contaminated by
microorganisms moving in from the outside from the outside