2. As a result of successfully completing this chapter, readers will be able to:
Define the term, “disinfection,” and explain how disinfection differs from
sterilization
Review factors that impact the effectiveness of a disinfectant
Discuss the relationship between the risk level (intended use) of the
device to be disinfected and the selection of a disinfectant
Explain disinfectant activity levels as they relate to the resistance of
microorganisms to germicidal agents:
◦ high-level disinfection
◦ intermediate-level disinfection
◦ low-level disinfection
3. Review factors which affect the chemical action of and other
important selection considerations for disinfections
Provide basic information about the types of disinfectants
commonly used in healthcare facilities: quaternary ammonium
compounds, phenolics, alcohol, halogens, glutaraldehyde,
ortho-phthalaldehyde, and formaldehyde
Review safety requirements that should be followed when using
chemical disinfectants
Define the term, “thermal disinfection,” and note key points to
ensure that it is occurring
4. Disinfectant - A chemical used on
inanimate objects such as medical
instruments to kill all microorganisms ,
except spores
Antiseptic – A chemical used on living
tissue such as skin, to slow the growth
of microorganisms
Sterile – Free from all living organisms
Disinfection – The destruction of
nearly all pathogenic microorganisms on
an inanimate surface. Disinfection is
accomplished using chemical or heat
processes
7. Excessive Moisture –
Excessive moisture can cause
disinfectant solutions to
become diluted. Lowering the
concentration of the chemical
disinfectant can reduce its
ability to kill microorganisms
Type and number of
microorganisms present
8. Direct Contact with the Item
In order to be effective, disinfectants must
make direct contact with all surfaces being
disinfected
Time
Disinfectants must be allowed time to work
Check manufacturer’s instructions for the
correct exposure time required to achieve the
desired biocidal effect
9. Temperature of the Disinfectant
pH
Hardness of the Water
Material Compatibility
Positioning of the Device(s) being disinfected
10. Should be based on:
◦ The intended use of the device
◦ The degree of disinfection
required for the device
◦ Risk levels are based on the
Spaulding Classification
System
11. Items introduced
directly into the
bloodstream or other
normally sterile areas
of the body
Surgical Instruments,
Implants, etc.
12. Items which come in
contact with intact
mucous membranes
Fiberoptic
Endoscopes,
Cystoscopes, etc.
13. Come in direct contact
with the patient’s
unbroken skin
Crutches, Blood
Pressure Cuffs,
equipment, etc.
14. Table Modified from Favero and
Bond, 1991
Classification of
Patient Care Items
CriticalSterilizationSterile body cavity
Semi-criticalHigh-levelMucous membranes
Non-criticalLow levelIntact skin
Item ClassDestruction
Method
Body Contact
16. Process that uses a sterilant for a shorter contact
time that needed for sterilization
High-level disinfection kills all microorganisms,
except bacterial spores
17. Process that utilizes a agent that kills viruses,
mycobacteria, fungi, and vegetative bacteria, but
not bacterial spores
18. Process that utilizes a agent that kills vegetative
forms of bacteria some fungi and lipid viruses
19. Lipid Virus – A virus whose core is
surrounded by a coat of lipoprotein.
Viruses included in this structural
category are generally easily
inactivated by many types of
disinfectants, including low-level
disinfectants
Non-lipid Virus – A virus whose core
is not surrounded by a lipid envelope.
These viruses are generally more
resistant to inactivation by disinfectants
20. Table Modified from Favero and
Bond, 1991
Hierarchy of Disease Producing Agents
Low-Level DisinfectionLipid or medium sized viruses
(Hantavirus, Herpes Simplex Virus)
Low-level DisinfectionGram Positive & Negative
Vegetative Bacteria
Intermediate-level DisinfectionFungi
Intermediate-level DisinfectionNonlipid and small viruses
(Poliovirus)
High Level DisinfectionMycobacteria
SterilizationBacterial spores
Extended Sterilization TimesPrions
Destruction MethodOrganism Producing Disease
21. Types of devices being disinfected
Whether items can be disassembled
Manufacturer’s recommendations
Positioning of the device
Process Quality Assurance Tests
Shelf Life and Use Life
Preparation required (mixing, etc.)
Reuse factors
Additional inspections required by the manufacturer
22. A detailed overview of
common chemical
disinfectant characteristics
can be found on pages
161 – 169 in the text.
24. Disadvantages:
◦ Not sporicidal
◦ Generally not tuberculocidal or virucidal against
hydrophilic viruses
◦ Not Compatible with Soap
◦ Absorbed or Neutralized by Cotton or Charcoal
◦ Not effective against some gram-negative organisms
commonly found in hospitals
25. Advantages:
◦ Broad Spectrum of use;
bactericidal for gram-
negative and gram-
positive bacteria, fungi,
and tuberculocidal
against lipophilic
viruses.
◦ Residual Activity* (can
also be a disadvantage)
Disadvantage
s:
◦ Not sporicidal
◦ Inactivated by organic
material
◦ Corrosive to Rubber
and some Plastics
26. Advantages:
◦ Rapid bactericidal agent
against vegetative
microorganisms,
tuberculocidal, fungicidal,
and virucidal
◦ Fast-Acting
◦ Non-Staining
◦ Leaves No Residue
Disadvantages:
◦ Requires a minimum 5 minute
wet contact.
◦ No residual activity
◦ Volatile, flammable
◦ Inactivated by Organic Soil
◦ Can dissolve lens mountings
on certain optical instruments
◦ Tends to harden and swell
plastic tubing
◦ Not sporicidal
28. Advantages:
◦ Effective against Gram-
Positive and Gram-
Negative
Microorganisms,
Tuberculocidal,
Fungicidal, and
Virucidal
◦ Rapid-Acting
Disadvantages:
◦ Inactivated by Organic
Matter
◦ Corrosive to Metals
◦ Not Sporicidal
◦ Stains fabrics, plastics
and other synthetic
materials
◦ Relatively Unstable
29. Advantages:
◦ Bactericidal,
Tuberculocidal, and
Virucidal
◦ Rapid-Action against
vegetative bacteria
Disadvantages:
◦ Corrosive to Metals
◦ Detrimental to Rubber
and some Plastics
◦ May burn tissue
◦ Stains fabrics and
other materials
◦ May require long
contact time to kill
some fungi
30. Advantages:
◦ Kills vegetative bacteria
(within 2 minutes)
◦ Bactericidal (gram-positive
and gram-negative),
tuberculocidal, fungicidal,
virucidal, sporicidal (For
sterilization (killing spores)
the soak time ranges 6-10
hours).
Disadvantages:
◦ Noxious odors, good
ventilation required
◦ Unstable (14-28 product
life)
◦ Dilution of product reduces
activity
◦ Vaporizes
◦ No cleaning ability
◦ Rinsing Required
◦ Employee Health Concerns
31. Advantages:
◦ Fast-acting
◦ User-friendly
◦ Compatible with a wide
range of endoscopes and
medical devices
◦ Requires no activation or
mixing
Disadvantages:
◦ Does not have sterilant
label claim
◦ Improper rinsing can cause
staining of patient tissues
◦ Patient with a history of
bladder cancer should not
be exposed to items
processed by OPA
32. Advantages:
◦ Bactericidal,
tuberculocidal,
fungicidal, and virucidal
◦ Sporicidal (as 8%
Formaldehyde/70%
alcohol)
Disadvantages:
◦ Inactivated by organic
material
◦ May stain fabrics, plastics,
and other synthetic
materials
◦ Not sporicidal
◦ Carcinogen (1PPM, 8 hour
TWA)
◦ Irritating fumes
33. Follow manufacturers’ instructions
Use appropriate containers
Cover the containers
Wear gloves
Reuse only those products labeled for reuse
Watch expiration dates
Test as necessary
Rinse thoroughly
Dispose of according to established guidelines
34. A Log Book should
be maintained for
high-level
disinfectants
(See page 171 of
the text for a sample
log book page)
35. Wear PPE
Use an exhaust hood when necessary
Develop a spill plan
Provide an eyewash/shower and other first aid
supplies
Provide easy access to a phone and phone
numbers for emergencies
Provide yearly staff training
Monitor disinfectants (including air quality)
36. Thermal Disinfection –
Disinfection accomplished by
heat
Check spray arms and nozzles
of mechanical
washer/disinfectors daily to
insure they are working correctly
Medical washers and
washer/disinfectors are
regulated by the FDA
