MICROBIOLOGY- LABORATORY SAFETY

Question 1

kills all forms of microbial life

Answer 1

Sterilization

Question 2

destroys pathogenic organisms

Answer 2

Disinfection

Question 3

removal of pathogenic microorganisms

Answer 3

Decontamination

Question 4

Factors affecting Sterilization, Disinfection, and Decontamination

Answer 4

-Organic load
-Type of organism present
-Concentration and exposure time
-Physical and chemical nature of the surface
-Temperature
-pH
-Humidity
-Presence of biofilm

Question 5

Methods of Sterilization

Answer 5

-Incineration
-Moist heat
- Dry heat
-Filtration
-Ionizing (gamma) radiation
-Chemicals

Question 6

Safest method and Effective against prions and infective proteins

Answer 6

Incineration

Question 7

What is the temperature range for incineration as a method of sterilization?

Answer 7

870°C-980°C

Question 8

What are the temperature settings for steam under pressure in moist heat sterilization?

Answer 8

121°C and 132°C

Question 9

What is the fastest and simplest method of sterilization?

Answer 9

Moist heat

Question 10

Which device is used for moist heat sterilization?

Answer 10

Autoclave

Question 11

What can moist heat sterilization be used to sterilize?

Answer 11

Biohazardous trash and heat-stable objects

Question 12

How long does dry heat sterilization typically require?

Answer 12

1.5-3 hours

Question 13

What temperature range is used in dry heat sterilization?

Answer 13

160-180°C

Question 14

What types of materials are suitable for dry heat sterilization?

Answer 14

Glassware, oil, petrolatum, or powders

Question 15

What types of substances can be sterilized using filtration?

Answer 15

Antibiotic solutions, toxic chemicals, radioisotopes, vaccines, and carbohydrates

Question 16

What type of membrane is used for filtering liquids in filtration sterilization?

Answer 16

Cellulose acetate or cellulose nitrate membrane with vacuum

Question 17

What type of filter is used for air in filtration sterilization?

Answer 17

High-efficiency particulate air (HEPA) filter

Question 18

What is the pore size of a HEPA filter used in air filtration?

Answer 18

0.3 µm

Question 19

What type of items are commonly sterilized using ionizing (gamma) radiation?

Answer 19

Disposables

Question 20

What is the most common chemical used in gaseous form for sterilization?

Answer 20

Ethylene oxide

Question 21

What can vapor-phase hydrogen peroxide be used to sterilize?

Answer 21

HEPA filters, metals, non-metal devices (medical instruments)

Question 22

What chemical is used in gas plasma form for sterilization?

Answer 22

Hydrogen peroxide

Question 23

Methods of Disinfection

Answer 23

• Physical methods
• Chemical methods
• Antiseptics

Question 24

What temperature and duration are required for boiling as a physical method of disinfection?

Answer 24

100°C for 15 minutes (effective against vegetative bacteria)

Question 25

What temperature and duration are used for pasteurization as a physical method of disinfection?

Answer 25

70°C for 30 minutes (effective against food pathogens)

Question 26

What type of radiation is used in non-ionizing radiation disinfection?

Answer 26

UV light

Question 27

What are the common types of alcohol used for disinfection?

Answer 27

60-90% ethyl or isopropyl alcohol solution

Question 28

Which chemicals are considered aldehydes and are sporicidal within 3-10 hours?

Answer 28

Formaldehyde and Glutaraldehyde

Question 29

What chemical is used for surface sterilization of surgical instruments?

Answer 29

Peracetic acid

Question 30

What concentration of hydrogen peroxide is commonly used for disinfecting inanimate objects?

Answer 30

3% hydrogen peroxide

Question 31

What type of compounds are used for disinfecting bench tops or other surfaces?

Answer 31

Quaternary ammonium compounds

Question 32

What class of chemicals, derivatives of carbolic acid (phenol), includes Amphyl?

Answer 32

Phenolics

Question 33

What group of chemicals includes chlorine and iodine and is used for disinfection?

Answer 33

Halogens

Question 34

What widely used antiseptic is known for its effectiveness?

Answer 34

Iodine

Question 35

What concentration of alcohol is commonly used as an antiseptic?

Answer 35

70% alcohol

Question 36

What antiseptic is used in a 1% solution?

Answer 36

Silver nitrate

Question 37

How should hazardous chemicals in the workplace be identified and marked?

Answer 37

With a National Fire Protection Association (NFPA) label stating the health risk.

Question 38

What provides guidelines on the proper labeling of chemical containers?

Answer 38

Chemical hygiene plan

Question 39

What documents provide detailed information about hazardous chemicals, including their properties and safety precautions?

Answer 39

Material Safety Data Sheets (MSDSs)

Question 40

What programs should workplaces have to ensure employees are informed about chemical safety?

Answer 40

Written chemical safety training and retraining programs

Question 41

What equipment is used to protect against chemical odors in laboratories?

Answer 41

Fume hoods

Question 42

Are fume hoods typically equipped with HEPA filters to trap pathogenic microorganisms?

Answer 42

No, fume hoods do not usually have HEPA filters for this purpose.

Question 43

Types of fire extinguishers

Answer 43

Type A: trash, wood, and paper Type B: chemical fires Type C: electrical fires Mnemonics Class A - Ang Tigas = Solids Class B- Basa = Liquids Class C- Curyente = Electrical

Question 44

HAZARDOUS MATERIALS CLASSIFICATION

Answer 44

YELLOW- REACTIVITY RED- FIRE HAZARD Flash Point BLUE- HEALTH HAZARD WHITE- SPECIFIC HAZARD

Question 45

RACE STANDS FOR?

Answer 45

RESCUE ALARM CONTAIN EXTINGUISH/ EVACUATE

Question 46

What was the aim of CDC's Universal Precautions in 1987?

Answer 46

To reduce the risk of HBV transmission in clinical laboratories and blood banks.

Question 47

According to the 1996 Standard Precaution guidelines, how should blood and body fluids from every patient be treated?

Answer 47

As potentially infectious. This guideline applies to blood and all body fluids except sweat.

Question 48

ENGINEERING CONTROLS

Answer 48

-Laboratory environment -Biologic Safety Cabinet -Personal Protective Equipment -Postexposure Control

Question 49

What should be prominently displayed on laboratory doors and equipment containing infectious material?

Answer 49

Biohazard symbol

Question 50

What is the primary purpose of Biologic Safety Cabinets (BSCs)?

Answer 50

To protect workers from aerosol exposure to infectious disease agents.

Question 51

How is the air inside a Biologic Safety Cabinet typically sterilized?

Answer 51

Either by heat, UV light, or most commonly, by passage through a HEPA filter.

Question 52

How are Biologic Safety Cabinets classified?

Answer 52

Into Class I-III according to the effective levels of biologic containment they provide.

Question 53

DESCRIBE Class I Biologic Safety Cabinet (BSC)?

Answer 53

-Allow room (unsterilized) air to pass into the cabinet and around the area and material within, sterilizing only the air to be exhausted -Negative pressure -May be ventilated to the outside or exhausted to the work area -Causally operated with an open front

Question 54

DESCRIBE Class II Biologic Safety Cabinet (BSC)?

Answer 54

-Sterilize air that flows over the infectious material as well as the air to be exhausted -Vertical laminar flow BSCs --Class IIA: self-contained, 70% of the air is recirculated into the work area --Class IIB: exhaust air is discharged outside the building, radioisotopes, toxic chemicals, or carcinogens

Question 55

DESCRIBE Class III Biologic Safety Cabinet (BSC)?

Answer 55

-Affords the most protection to the worker -Completely enclosed and have negative pressure, most protection to the worker -Infectious material is handled with rubber gloves that are attached and sealed to the cabinet

Question 56

Examples of PPEs include

Answer 56

-Fluid repellent facemask - Apron -Gloves - disposable goggles or full-face visor - FFp3 respirator - Long sleeved disposable gown

Question 57

What are the Post Exposure Control

Answer 57

-All laboratory accidents and potential exposures must be reported to the supervisor and safety officer -Prophylaxis: Hepatitis B virus immunoglobulin (HBIG) or HBV booster immunization in the event of exposure to Hepatitis B -Postexposure prophylaxis: Neiserria meningitidis (possible disease transmission) -HIV testing

Question 58

Classification of Biologic Agents Based on Hazard

Answer 58

* Biosafety Level 1 (BSL-1) * Biosafety Level 2 (BSL-2) * Biosafety Level 3 (BSL-3) * Biosafety Level 4 (BSL-4)

Question 59

What are the characteristics of organisms classified under Biosafety Level 1 (BSL-1)?

Answer 59

-They have no known potential for infecting healthy people. -They are well-defined and characterized. -Examples include Bacillus subtilis and Naegleria gruberi.

Question 60

What are the characteristics of organisms classified under Biosafety Level 2 (BSL-2)?

Answer 60

-They are most commonly found in clinical specimens. -They include agents of infectious diseases such as HIV, HBV, Salmonella organisms, and several others.

Question 61

What are the characteristics of organisms handled under Biosafety Level 3 (BSL-3)?

Answer 61

o Handling of material suspected of organisms unlikely to be encountered in a routine clinical laboratory o Mycobacteium tuberculosis, Coxiella burnetii, and mold stages of fungi o Primarily transmitted by infectious aerosol

Question 62

What are the characteristics of organisms handled under Biosafety Level 4 (BSL-4)?

Answer 62

o Exotic agents that are considered high risk and cause life-threatening disease o Marburg virus or Congo-Crimean hemorrhagic fever o All procedures are performed under maximum containment (Class III BSC) o Usually handled by health or research laboratories