MICROBIOLOGY- LABORATORY SAFETY Flashcards
kills all forms of microbial life
Sterilization
destroys pathogenic organisms
Disinfection
removal of pathogenic microorganisms
Decontamination
Factors affecting Sterilization, Disinfection, and Decontamination
-Organic load
-Type of organism present
-Concentration and exposure time
-Physical and chemical nature of the surface
-Temperature
-pH
-Humidity
-Presence of biofilm
Methods of Sterilization
-Incineration
-Moist heat
- Dry heat
-Filtration
-Ionizing (gamma) radiation
-Chemicals
Safest method and Effective against prions and infective proteins
Incineration
What is the temperature range for incineration as a method of sterilization?
870°C-980°C
What are the temperature settings for steam under pressure in moist heat sterilization?
121°C and 132°C
What is the fastest and simplest method of sterilization?
Moist heat
Which device is used for moist heat sterilization?
Autoclave
What can moist heat sterilization be used to sterilize?
Biohazardous trash and heat-stable objects
How long does dry heat sterilization typically require?
1.5-3 hours
What temperature range is used in dry heat sterilization?
160-180°C
What types of materials are suitable for dry heat sterilization?
Glassware, oil, petrolatum, or powders
What types of substances can be sterilized using filtration?
Antibiotic solutions, toxic chemicals, radioisotopes, vaccines, and carbohydrates
What type of membrane is used for filtering liquids in filtration sterilization?
Cellulose acetate or cellulose nitrate membrane with vacuum
What type of filter is used for air in filtration sterilization?
High-efficiency particulate air (HEPA) filter
What is the pore size of a HEPA filter used in air filtration?
0.3 µm
What type of items are commonly sterilized using ionizing (gamma) radiation?
Disposables
What is the most common chemical used in gaseous form for sterilization?
Ethylene oxide
What can vapor-phase hydrogen peroxide be used to sterilize?
HEPA filters, metals, non-metal devices (medical instruments)
What chemical is used in gas plasma form for sterilization?
Hydrogen peroxide
Methods of Disinfection
- Physical methods
- Chemical methods
- Antiseptics
What temperature and duration are required for boiling as a physical method of disinfection?
100°C for 15 minutes (effective against vegetative bacteria)