This document discusses the use of disinfectants in hospitals. It defines types of disinfectants like sterilants, high level disinfectants, and low level disinfectants. It also covers factors that affect disinfectant efficacy and the ideal properties of disinfectants. Specific high level disinfectants discussed include glutaraldehyde, hydrogen peroxide, orthophthaldehyde, and peracetic acid. Intermediate level disinfectants mentioned are chlorine compounds and iodophors. The document also summarizes the uses and properties of various disinfectants.

1. Disinfectant Use
In Hospital
 Dr. Yogita Mistry
 GMC,Surat

2. Objectives:
 Definition
 Categories of disinfectant
 Factors affecting efficacy of disinfectant
 Property of Ideal Disinfectant
 Different disinfectant with few points
 Use of disinfectant in hospital
 Use of disinfectant in our hospital

3. Definition
Sterilization- is the process that kills all the living
micro-organisms including spores, viruses and
fungi.
Disinfectants –are those germicides or chemical
substances which are used to destroy or inhibit
the growth of pathogenic vegetative bacteria (not
their spores) on inanimate (nonliving )surfaces
such as glassware or surgical instruments.
Antiseptics-are those germicides or chemical
substances which are used to destroy the
pathogenic bacteria (not the spores) on animate
(living) surfaces such as skin /mucous
membranes.

4. Definition
 Decontamination- means marked reduction
or destruction of viable pathogenic organisms
to a level that will allow a healthy persons
natural defenses to prevent any infection.
 Sanitation- means reduction in microbial load
from an inanimate surface to a level set forth
by public health department.

5.  Chemical steriliant: When chemical are used to
destroy all forms of microbial life(including spores) , it is
called chemical sterilient. For these disinfectant are
used with prolonged exposure time.(3-12 hours).
 High level disinfectant: When a chemical sterilient
with same concentration is used for shorter exposoure
period, it can kill all microorganisms except large
number of bacterial spores.
 Low level disinfectant: Can kill most vegetative
bacteria, some fungi and virus.
 Intermediate level disinfectant: Might be cidal for
mycobacteria, vegetative bacteria, most viruses, most
fungi, but not spore.

6.  Cleaning: Removal of visible soil (organic and
inorganic material) from objects and surface. It is
an essential step before high level disinfectant or
sterilization.

7. A rational approach to
disinfection and
sterilization

8.  Spaulding believed the nature of disinfection
could be understood readily if instruments and
items for patient care were categorized as
critical, semicritical, and noncritical according
to the degree of risk for infection involved in
use of the items.

9.  Critical Items
 Critical items confer a high risk for infection if they
are contaminated with any microorganisms.
 Object that enter sterile tissue/vascular system
 Example:
 Surgical instruments
 Cardiac & urinary catheter
 Implants
 USG probes used in sterile body cavity

10.  Sterile
 Heat sensitive items: ETO, hydrogen peroxide or
 Liquid chemical sterilients:
 2.4% gluteraldehyde based formulation
 0.95% gluteraldehyde + 1.64% phenol /phenate
 7.5% stabilized hydrogen peroxide
 7.35% stabilized hydrogen peroxide+0.23%
peracetic acid
 0.2% peracetic acid
 0.08% peracetic acid+1% hydrogen peroxide

11.  Semicritical Items:
 Items which contact mucous membrane/ non intact skin
 Respiratory therapy, anesthesia equipment
 Laryngoscope blade
 Esophageal manometry probes
 Cystoscope
 As these mucous membrane are usually infected by
microorganisms and not by spores. So small no. of
spores are permissible.
 High level disinfectant used for short time/ Intermediate
level disinfectant (sodium hypochlorite/iodophors)

12.  Non critical items:
 Those that come in contact with intact skin but not
mucous membrane
 Bedpans
 Blood pressure cuff
 Computers
 Bedside table, furniture,floor
 Cleaning at regular interval
 Mopping with water, detergent, disinfectant(low
level disinfectant-phenol/quternary ammonium
componds)

13. Factors affecting the
efficacy of disinfectant

14.  Number and location of microorganism
 Innate resistant of microorganisms
 Bacterial spore>
cryptosporidium>mycobacteria>nonlipid /small
viruses> fungi> vegetative bacteria> Lipid/medium
size virus
 Gn=Gp
 Rickettsia, chlamydia, mycoplasma
 prions

15.  Concentration and potency of disinfectant
 Physical and chemical factors
 Temperature
 High pH=Gluteraldehyde, Quternary ammoniym
compounds
 Low pH= Phenol, Hypochlorite, Iodine
 pH works by altering the disinfectant molecules/cell
surface
 Humidity= effects on gaseous
disinfectant(formaldehyde,chlorine dioxide)
 Water hardness= high cations=make insoluble ppt with
disinfectant= decrease killing of organisms

16.  Organic and Inorganic matters:
 Interfere with antimicrobial activity of disinfectant by
 Chemical reaction between organic materials and
disinfectant resulting in a complex formation that
are less or no germicidal.
 By protection of microorganisms from attack
 Duration of exposure
 Biofilms
 Residual proteins and salt

17. Microbial Contamination Of
Disinfectant
 Leads to HAI
 Not reported with high level disinfectant/ sterilient
 They are usually not contaminated at point of
manufacture, but contaminated during use, storage,
dilution

18. Property Of Ideal Disinfectant
 Broad spectrum: should have a wide
antimicrobial spectrum
 Fast acting: should produce a rapid kill
 Not affected by environmental factors: should
be active in the presence of organic matter (e.g.,
blood, sputum, feces) and compatible with soaps,
detergents, and other chemicals encountered in
use
 Nontoxic: should not be harmful to the user or
patient
 Surface compatibility: should not corrode
instruments and metallic surfaces and should not
cause the deterioration of cloth, rubber, plastics,
and other materials

19.  Residual effect on treated surfaces: should leave
an antimicrobial film on the treated surface
 Easy to use with clear label directions
 Odorless: should have a pleasant odor or no odor to
facilitate its routine use
 Economical: should not be prohibitively high in cost
 Solubility: should be soluble in water
 Stability: should be stable in concentrate and use-
dilution
 Cleaner: should have good cleaning properties
 Environmentally friendly: should not damage the
environment on disposal

20. High Level Disinfectant
 Formaldehyde
 Gluteraldehyde
 Orthophtahdehyde
 Hydrogen peroxide
 Peracitic acid

21. Formaldehyde
 Formaldehyde is used as
a disinfectant and sterilant
both in the liquid and
gaseous states.
Formaldehyde is sold and
used principally as a
water-based solution
called formalin, which is
37% formaldehyde by
weight. The aqueous
solution is bactericidal,
tuberculocidal, fungicidal,
virucidal and sporicidal

22. Formaldehyde
 Formaldehyde should be
handled in the workplace as a
potential carcinogen with an
employee exposure standard
that limits an 8 hour time-
weighted average exposure to a
concentration of 0.75 ppm. For
this reason, employees
should have limited
direct contact with
formaldehyde and these
considerations limit its
role in sterilization and
disinfection processes

23. Formaldehyde
 MOA: Alkylating amino and sulfhydral groups of
proteins and ring nitrogen atoms of purine base
 Microbicidal action:
 2%=Most virus
 8%=Poliovirus
 4%=Tuberculocidal in 2 minutes for 104 bacilli
 2.5% =Salmonella typhi
 4%=Sporicidal with 2 hour exposure
 Use: to prepare viral vaccine (polio, influenza)
 To preserve anatomical specimen

24. Gluteraldehyde
 Aldehydes have a wide
germicidal spectrum.
Gluteraldehydes are
bactericidal, virucidal,
fungicidal, sporicidal and
parasiticidal. They are
used as a disinfectant or
sterilant in both liquid and
gaseous forms. They
have moderate residual
activity and are effective
in the presence of limited
amounts of organic
material

25. Gluteraldehye
 High level disinfectant & chemical sterilent
 Aqueous solution=acidic and not sporicidal, only
when it is alkaline “activated” solution and it will
be sporicidal
 Once activated self life is 14 days
 Newer gluteraldehyde formulation:
 Gluteraldehyde+phenol+ sodium phenate
 Potentiated acid gluteraldehyde
 Stabilized alkaline gluteraldehyde

26.  MOA: alkylation of sulfhydryl , hydroxyl, carboxy
and amino groups of microorganism which alters
RNA, DNA, protein systhesis
 Use: As a high level disinfectant for medical
equipment such as endoscope, spirometry tubing,
dialyzer, anaesthesia and respiratory equipment
 S/e: irritant, dermatitis, mucosal irritation,
pulmonary syndrome, epistaxis, asthama,rhinitis

27. Hydrogen peroxide
 MOA: Generate destructive hydroxyl free radical
which attack membrane lipid, DNA, essential cell
membrane
 Broad acting
 Use: stable and effective disinfection of inanimate
surfaces
 0.5%=Bactericidal & virucidal in 1 minutes,
tuberculocidal in 5 minutes
 3%=VRE
 7%=Sporicidal
 6%-25%=Chemical steriliant
 13.4%= New rapid acting available

28. Hydrogen Peroxide
 Stabilized peroxides
may also be blended
with iodophors or
quaternary ammonia.
Hydrogen peroxide is
also blended with
paracetic acid in high
concentrations for use
as a high-level
disinfectant

29. Orthophthaldehyde
 MOA: interaction with aminoacid, protein,
microorganism
 Excellent microbicidal activity in vitro over a wider
pH range as comparable as gluteraldehye
 Not irritant to eye/nasal mucosa
 Disadvantage: it will stain the protein gray
 Use as a high level disinfectant

30. Peracetic acid
 Rapid action against all microorganisms
 Enhance the removal of organic material and
leaves no residue
 Remain effective in presence of organic matter
and is sporicidal even at low temperatures
 MOA: denaturation of proteins, disrupt the cell
wall permiability
 Use: as a high level disinfectant for cleaning of
endoscopes

31. Intermediate Level
Disinfectant
 Chlorine and chlorine compounds
 Iodine and Iodophors

32. Chlorine and Chlorine compunds
 Hypochlorite available as :
 Liquid(sodium hypochlorite)
 Solid (calcium hypochlorite)
 5.25%-6.25% sodium hypochlorite=House hold
bleach
 Its microbial activity is attributed largely to
undissociated hypochlorous acid (HOCL)
 Dissociation of HOCL depends on pH
 Disinfectant efficacy of clorine decreases with
increase in pH that lead to HOCL=OCL-

33.  Chlorine agents are most
commonly used due to:
 Broad spectrum of
antimicrobial activity
 No toxic residue
 Unaffected by water
hardness
 Inexpensive
 Fast acting
 Remove dried/fixed
organism and biofilms from
surface
 Low incidence of serious
toxicity

34. Hypochlorite's
 Other disadvantages of
hypochlorites include
corrosiveness to metals in
high concentrations (>500
ppm), inactivation by
organic matter, discoloring
or “bleaching” of fabrics,
and release of toxic
chlorine gas when mixed
with ammonia or acid.

35. Side effects of household bleach
concentration
 Occular irritation/ oropharyngeal, esophageal
gastric burns
 Discolouration/ bleaching of fabrics
 Release of toxic chlorine gas when mixed with
amonia/acid

36.  Alternative chlorine compounds are:
 Demand release chlorine dioxide
 Sodium dichloroisocyanurate
 Chloramine-T
 Advantage:
 They retain chlorine longer
 More prolonged bactericidal effects
 It is acidic from so HOCL remain for longer time

37. Microbicidal activity
 5000ppm=10 6 Cl.difficle spore in less than 10
minutes
 1000 ppm=M.tb
 500 ppm=Candida in 30 seconds
 100 ppm=B.atropheaus in lesstthan 5 minutes,
106-107 S.aureus, Salmonella, Proteus,
pseudomonas
Bleach Dilution Chlorine level in
ppm
5.25-6.25% None 52500-61500 (5 liter)
1:10 5250-6150 (4500-
500)
1:100 525-615 (4900-
100)
1:1000 53-62 (4950-
50)

38. Use:
 Tonometer head,
 For decontamination of blood spill
 Disinfection of water supply
 Legionella contaminated hospital water

39. Iodine And Iodophor
Disinfectants
Iodine tinctures:
2% iodine + 2.4% sodium
iodide (NaI) in 50% ethanol; It
is used as a skin disinfectant,
as a nonirritant antiseptic on
wounds and abrasions.
Strong iodine tincture:
Contains 7% iodine and 5%
potassium iodide (KI)
dissolved in 95% ethanol.
It is more potent but also more
irritating than tincture of
iodine.

40. Idophors
 Combination of iodine and solubilizing agent/ carrier
 Which causes sustained release of iodine
 Example: povidone iodine=polyvinylpyrrolidone and
Iodine, which is free of toxicity and irritant effects
 It must be diluted according to manufacturer’s
direction
 MOA: protein and nucleic acid disruption
 It is bactericidal, tuberculocidal, virucidal but it require
prolong contact time
 Use: disinfection of blood culture bottles, medical
equiment-thermometer, endoscope
 Not use on silicone catheter: due to adverse effects
on silicone tubing

41. Skin disinfectant Surgical
scrubs

42. Low Level Disinfectant
 Phenol
 Quaternary ammonium compounds
 Alcohol
 Surfactant
 Heavy metals

43. Alcohol
 Ethyl alcohol, Isopropyl alcohol, Methyl alcohol
 MOA: Denaturation of protein
 Absolute ethyl alcohol= less batericidal than
water+ alcohol because denaturation is quick in
presence of water.

44. Microbicidal activity
No acitivity when diluted by 50%
Methyl alcohol Ethyl alcohol Isopropyl alcohol
Weak bactericidal 60-80% =
Bactericidal,
Virucidal(enveloped/nonenvelo
ped)fungicidal (tissue phase>
culture phase)
95%= Tuberculocidal
All except non
enveloped virus

45. Alcohols
 Alcohols are commonly
used topical antiseptics.
 They can be used as a
reasonable substitute
for handwashing as
long as hands are not
visibly soiled.
 They are also used to
disinfect the surface of
medical equipment.
Alcohols require time to
work and they may not
penetrate organic
material.

46. Alcohols
 They also evaporate
rapidly which makes
extended exposure time
difficult to achieve unless
the items are immersed.
Alcohol irritates tissues.
They are generally too
expensive for general use
as a surface disinfectant

47.  Not recommonded for sterilizing medical and
surgical material due to lack of sporicidal action
and they can not penetrate protein rich material
 Use in disinfection of oral/rectal thermometer,
scissers, stethoscopes

48. PHENOLICS
 Examples: Benzyl-4-chlorophenol, Amyl phenol,
Phenyl phenol
 Advantages and disadvantages: good general
purpose disinfectants, not readily inactivated by
organic matter, active against wide range of
organisms (including mycobacterium), but not
sporicidal.

49. Phenol as Disinfectant
 They are not effective
against nonenveloped
viruses and spores. These
disinfectants maintain
their activity in the
presence of organic
material. This class of
compounds is used for
decontamination of the
hospital environment,
including laboratory
surfaces, and noncritical
medical items

50. Phenol as Disinfectant
 Phenolics are not
recommended for semi
critical items because of
the lack of validated
efficacy data for many of
the available formulations
and because the residual
disinfectant on porous
materials may cause
tissue irritation even when
thoroughly rinsed.

51. Phenol as Disinfectant
 Phenolics are not
recommended for semi
critical items because of
the lack of validated
efficacy data for many of
the available formulations
and because the residual
disinfectant on porous
materials may cause
tissue irritation even when
thoroughly rinsed.

52. Surfactants
 Decrease surface tension
 Soaps and detergents
 Quaternary ammonium compounds : microbicidal

53. Antiseptics
 Biguanides:
Chlorhexidine
 Low toxicity
Used on skin
and mucous
membranes

55. Although chlorhexidine is effective in the presence of
blood, soap, and pus, its activity is reduced

56. Heavy Metals
 Denature proteins
 silver nitrate (topical cream)
 mercuric chloride (paint)
 copper sulfate (algaecide)
 zinc (mouthwash, paints)

58. Mercurochrome-antiseptic

59. Zinc+ ferric oxide

60. Antifungal action

61. Uses Of
Disinfectant In
Hospital

62.  Hospital equipments
 Reprocessing of Endoscope
 HAI
 Heat sensitive endoscopes-GI , Bronchoscope, nasopharyngeoscope
 All must be properly cleaned first .
 Should minimally subjected to high level disinfectant
 Most common in use : 2% gluteraldehyde for 20 minutes
 Other imp: Orthophthaldehyde 0.55% (is now replacing gluteraldehyde due
to its less irritant property on eye and nasal mucosa,12 minutes)
 Other:
 7.35% hydrogen peroxide + 0.23% peracitic acid
 1 % hydrogen peroxide+ 0.08% peracitic acid
 7.5 % hydrogen peroxide
 But all 3 are more corrosive and causing functional damage on endoscope
 Automated endoscope reprocessors

63. Cleaning:
 Important process before using disinfectant
 Removal of soil and organic material from objects
 Normally done by water with detergent and enzymatic
products
 Enzymes: proteases: to remove blood and pus
 Lipase: enzymatic action on fat
 Amylase: starch
 It can be done mannually or by ultrasonic cleaners/water
-disinfector
 2 essential components of manual cleaning
 Friction-rubbing/scrubbing the soiled area with a brush
 Fluidics-fluids under pressure, use to remove soil and
debris from internal channels after brushing
 All enzymes =must be rinsed

64. 5 steps in reprocessing
 Cleaning: Mechanically cleaning of internal and external
surfaces by brushing, flushing with water and detergent
with /without enzymes
 Disinfection: Immerse endoscope in high level
disinfectant / chemical sterilient & perfuse. Disinfect all
accessible channels.
 Rinse: With sterile /filtered/tap water (that meets federal
clean water standard at point of use)
 Dry: Rinse with alcohol and dry with forced air after
disinfectant and before storage
 Storage: To prevent redecontamination and to promote
drying. Hanging vertically in a ventilated cabinets-good
method

65. Dental instruments

66. Type of instruments Example Method of
disinfection
Instruments that
penetrates soft tissue
and bone
Extraction forcep,
scalpel blade, bone
chisels, periodontal
scales, surgical burs
Critical items
Should be discarded or
sterilized only
Not penetrating bone
and soft tissue
Air / water syringe,
amalgam condensors
Semicritical items
Sterilized/ high level
disinfectant
Clinical contact
(Surfaces that might be
touched frequently with
gloved hands during
patient care)
Light handles,
switches, dental x-ray
equipments, chair side
equipment
Use barrier protective
covering, disinfect on
each day of use with
low or intermediate
level disinfectant
House keeping
surfaces
Clean with water,
detergent, disinfectant

67. Disinfection of HBV, HCV, HIV,
Tb contaminated items
 High level disinfectant is appropriate (CDC)
 For HCV : 2% gluteraldehyde for 20 minutes
 Chlorine compound are ineffcetive

68. In Hemodialysis Units
 In includes Hemodialysis machines, Water supply,
Water treated systems, Distribution system
 Non –critical surface: Dialysis chair/bed,
Countertops, External surface of machine,
Equipments
 Disinfect with EPA registered disinfectant/
hypochlorite solution (500-600 free chlorine)
 Hemodialyser: 7.2% peracetic acid, 20%
formaldehyde,

69. Inactivation Of Cl.difficle
 Carpeted room> non carpeted room
 Hypochlorite solution(1600 ppm available
chlorine)
 Contaminated medical devices like
colonoscopes & thermometers= 2%
gluteraldehyde for 20 minutes or
orthophthaldehyde with peracetic acid
 Hand washing, barrier methods, environmenta
cleaning

70. For Occupational exposure Of
Blood borne pathogens
 Disinfectant must be tuberculocidal
 M/c is hypochlorite solution (1:10 or 1:100
dilution)
 In presence of large spill: 1:10

71. Emerging pathogens
 Cryptosporidium: Most disinfectant not effective
except 6%-7.5% hydrogen peroxide
 E.coli O157:H7: Chlorine 1 ppm for 1 minutes
 H.pylori: Ethanol (80%), Gluteraldehyde (0.5%),
Chorhexidine gluconate (0.05-1%), Povidone iodine
(0.1%), Sodium hypochlorite (150 ppm)
 Rotavirus: 95% Ethanol, 70% Isopropanol, 2 %
Gluteraldehyde, 0.35% Peracetic acid, Sodium
hypochlorite(800 ppm free chlorine), Phenol based
products (14.7% )

72.  HPV and noroviruses: Not 100 % inactivation by
disinfectant
 SARS: 70% Ethanol and Povidone iodine for 1
minutes, 2.5% Gluteraldehyde for 5 minutes

73. Bioterrorist agents
 Susceptibility of these agents to germicide invitro
is similar to that of other related pathogen
(B.anthrax=B.athropheus)
 Many of them are stable enough in the
environment leads to transmission of agents.
 Data suggest that current disinfection and
sterilization practices are appropriate for
managing patient care equipment and
environment surfaces when potentially
contamination with bioterrosrist agents

74. Suceptibility Of Antibiotic
Resistant Bacteria To Disinfcetion
 Both are not related to each other except with few
exceptions like:
 MRSA strains –less susceptible than MSSA
starins to chlorhexidine, propamide, quternary
ammonium compounds, but are equally
susceptible to phenol

75. Air disinfection in patient care
areas
 Disinfection spray fog techniques are unsatisfactory
in patient care area.
 Other methods: Air filteration, UV radiation, Chlorine
dioxide

76. OT Disinfection
 Sterilization 100% is not achivable.
 It require standard air flow pattern, standard cleaning,
disinfection also.
 Fumigation: Formaldehyde gas is use
 Prepared by adding 150 gram of KMNO4 to 300 ml of
formaline for every 1000 cubic feet of space.
 Room should be tightly closed and sealed for 12-24 hours.
 It is carcinogenic
 Neutralization should be done by 250 ml of 10% amonia/
liter of formaline used is placed in centre of room for 3
hours.
 OT should be ventilated before the entry of any person.
 Ideally should be done on week ends.

77.  Newer agents: Hydrogen peroxide with silver
nitrate/ peracetic acid/other compounds
 Contact hours: 1 hour
 OT can be used within 1 hour
 VIKRON: Contain
 Pottasium peroxymonosulphate,
 Sodium dodecyl benzenesulphate, sulphanic acid,
inorganic buffer.
 Can be used for managing spill in OT.

78. Surface cleaning/
disinfection
 Non critical items
 Divided as Housekeeping and medical
equipments surface
 Housekeeping: Hospital floor, bed site table,
furniture, door knobs, handles
 Only soap and water are ineffective. Disinfectant
should be used. Phenolic compounds=94-99.9%

79.  Major problem:
 Bacterial counts are nearly back to its pretreatment
level within few hours.
 Ideally disinfectant should be left for 10 minutes on
surface, but such long time is not practical.
 Multiple scientific paper have demonstrated significant
microbial reduction with contact time of 30-60 seconds.
 Mop water become increasingly dirty during cleaning.
 Some hospital uses a new mopping technique
‘microfiber material’ to clean the floor.
 They are densly constructed, polyester/polyamide fibers
 1/16 the thickness of a human hair
 Positively charged , so attract the dust are more
absorbant than a conventional cotton-mop.

80. In our hospital
OT disinfection Formaldehyde gas
Instruments Sterilied by autoclave / ETO/ plasma
sterilized supplied by CSSD
Patient care before OT Betardine wash
At the time-local site cleaning By betardine
Endoscope Gluteraldehyde/ Automated machine
ENT ward instruments Kept in savlon. Then boied in DW
for 20 minutes. The dried and
reused.
OT table, Trolley Cleaning with hypochlorite
MICU Diluted savlon is kept in container
for health workers to clean the
hands inbetween
Hemodializer Company provided disinfectant run
by machine itself

81. References:
 Top ten disinfectants to control HAIs.
http://www.hospitalmanagement.net/features/feat
ureppcdisinfectantshaiglobaldata.
 Guideline for Disinfection and Sterilization in
Healthcare Facilities, 2008.
William A. Rutala, Ph.D., M.P.H.1,2, David J. Weber, M.D., M.P.H.1,2,
and the Healthcare Infection Control Practices Advisory Committee
(HICPAC).
 CDC-A Guide to Selection and Use of
Disinfectants.
 Shridhar rao- Testing of disinfectant.

82. Thank you