Jan 29, 2016
Chemical
DefinitionDefinition
Sterilization: The freeing of an article from all living organisms including bacteria and their spores.
Disinfection: Removal of some types of pathogenic organisms usually not including spores.
DISINFECTANT:
Chemical substances used for sterilization of inanimate objects (toxic to human)
ANTISEPTIC:
Chemical substance that used for sterilization of animate objects (not toxic to human)
Chemical MehodsChemical Mehods
Destroys1.All vegetative bacteria (except tubercle bacilli)
2.Enveloped viruses3.Some fungi
Examples1.Phenol group2.Quaternary ammonium compound
PhenolPhenol
Mouth washesScrub soapsSurface and household disinfectantsPhenol 5% used as disinfectant of stool in
typhoid or sputum in T.B
Quaternary ammonium compoundQuaternary ammonium compound
Surface disinfectantContraindicated as antiseptics
DestroysAll vegetative bacteria (including
tubercle bacilli)Enveloped and some non-enveloped
virusesMost fungi
ExamplesAlcoholHydrochloritesIodine and iodophores
AlcoholAlcohol
Examples:1.Ethyl alcohol2.Isopropyl alcohol
Uses:1.Topical antiseptics2.Disinfect the surface of medical
equipment
HypochloriteHypochlorite Examples: Clorox
Uses: Household bleach Surface disinfectant Water disinfectant
Iodine and Iodophore Iodine and Iodophore disinfectantsdisinfectants
1. Antiseptic2. Disinfection of blood
culture bottles3. Disinfection of
medical equipments such as thermometers and endoscopes
DestroysAll vegetative bacteria (including tubercle
bacilli)Enveloped and some non-enveloped virusesFungiSome bacterial spores
ExamplesH2O2GluteraldehydeFormaldehydePeracetic acid
H2O2H2O2
Mouth gurgleAntiseptic to clean wounds
GluteraldehydeGluteraldehyde
Example: Cidex
Uses: Very potent disinfectant
Disadvantages: Highly toxic used under trained supervision in a
well ventilated setting and with appropriate personal protective equipment
FormaldehydeFormaldehydeExample:Formalin, formadon
Uses:Disinfectant in both liquid and gaseous
state
Disadvantages:Potential carcinogen
ClassificationItemsExamplesReprocessing
Critical items (high risk)
Items that penetrate soft tissues
Surgical InstrumentsIUDVascular cathetersimplants
cleaning followed by sterilization
Semicritical items
(intermediate risk)
Items that in close contact with mucous membranes or with non intact skin
Respiratory equipments, flexible endoscopes, laryngoscopes, endotracheal tubes, thermometers.,
Cleaning followed by high level disinfection
Non critical item
(low risk)
Items that come in contact with normal and intact and inanimate environment skin
StethoscopeWalls, floors, ceiling,Furniture, sinks.
Cleaning and /or low level disinfection
ItemMethod of sterilization
Cat gutIonizing radiation
Endoscopes2% Gluteraldehyde 30 min, 10% phenol 6 hrs, ethylene oxide
Disposable syringesEthylene oxide, ionizing radiation
Egg/serum mediaInspissation (80 o C,30 min, for 3 days)
Faeces, urine, vomitusBleaching powder, cresol
Heart-lung machineEthylene oxide
Endoscope washer
ItemMethod of sterilization
Infected materialsIncineration
Lab mediaAutoclave(121 o C, 20min)
Oils, powders, glasswareHot air oven (160 o C 2 hrs, 180 o C 1 hr)
Operation theatre/roomFormaldehyde gas
Plastic/polythelene tubes Ethylene oxide, 2% gluteraldehyde
Serums, fluidsWater bath( 56 o C, 1 hr)
SkinTincture iodine, 70% methylated alcohol(spirit), savlon
ItemMethod of sterilization
SputumBurning, autoclave
Suture materialAutoclave
Thermometer, cheatle forceps10% chlorhexidine+ cetrimide 1% for 10 min
Toxins, antibiotic solutions, blood products
Filtration
VaccinesVaccine bath (60 o C , 1 hr)
Surgical instrumentsH2O2 gas plasmaAutoclaveInfra-red (metal instruments)
GownsAutoclave