2 - BIOSAFETY CABINET

Question 1

are enclosed workspaces with a
ventilated hood that is designed to contain pathogenic microorganisms
during microbiological processes.

Answer 1

Biological Safety Cabinet

Question 2

is an engineering control intended to protect laboratory workers, the laboratory environment, and work materials from exposure to infectious or biohazardous aerosols and splashes.

Answer 2

Biological Safety Cabinet

Question 3

What does BSC uses to provide protection

Answer 3

uses inward directional airflow,
high-efficiency particulate air (HEPA) filtration,
laminar airflow

Question 4

Air is guided in only one direction, towards the inside of the BSC and away from you. Contaminated air is kept inside the BSC. This is called

Answer 4

inward directional flow

Question 5

HEPA-filtered air flows downward onto the work surface. The airflow is parallel, smooth, and does not easily mix while you work.

Answer 5

Laminar airflow

Question 6

Air exhausted from the BSC is HEPA-filtered and may be either

Answer 6

recirculated or removed

Question 7

❑It removes the most penetrating particle size (MPPS) of 0.3 μm with an efficiency
of at least 99.97 %

Answer 7

HEPA (High efficiency particulate air) Filter

Question 8

The typical HEPA filter is a

Answer 8

single sheet of borosilicate fibers treated with a wet-strength water-repellant binder

Question 9

HEPA removes particulate matter by this three mechanisms

Answer 9

interception, impaction, diffusion

Question 10

The HEPA filtering efficiency depends upon

Answer 10

fiber diameter, filter thickness and face velocity

Question 11

The filter medium is pleated to increase the overall surface area, with pleats being separated by

Answer 11

corrugated aluminum tubes

Question 12

(HEPA Filtration Mechanisms)
- larger particles are unable to avoid fibers by following the curving contours of
the air stream and are forced to embed in one of them directly

Answer 12

Impaction

Question 13

(HEPA Filtration Mechanisms)
- particles below 0.3 μm are captured by this mechanism in a HEPA filter. As a result of the collision with gas molecules by the smallest particles, especially those below 0.1 μm in diameter. The small particles are effectively blown or bounced around and collide with the filter media fibers.

Answer 13

Diffusion

Question 14

(HEPA Filtration Mechanisms)
- particles following a line of flow in the air stream come within one radius of a fiber and adhere to it. Mid size particles are being captured by this process.

Answer 14

Interception

Question 15

A microorganism that is unlikely to cause human disease or animal disease.

Answer 15

❑Risk Group 1 (no or low individual and community risk)

Question 16

• A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment. Laboratory exposures may cause serious infection, but effective treatment and preventative measures are available and the risk of spread of infection is limited.

Answer 16

❑Risk Group 2 (moderate individual risk, low community risk)

Question 17

A pathogen that usually causes serious human or animal disease but does not ordinarily spread from one infected individual to another. Effective treatment and
preventive measures are available.

Answer 17

❑Risk Group 3 (high individual risk, low community risk)

Question 18

A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available.

Answer 18

❑Risk Group 4 (high individual and community risk)

Question 19

is the most basic biosafety cabinet that provides protection to the environment and the laboratory personnel.

Answer 19

Class I

Question 20

are typically used to either enclose specific equipment like centrifuges or
for procedures like aerating cultures that might potentially generate aerosols.

Answer 20

Class I

Question 21

Biosafety cabinets of this class are either ducted (connected to the building exhaust system) or unducted (recirculating filtered exhaust back into the laboratory).

Answer 21

Class I

Question 22

❑The room air is drawn in through the opening that also allows the entry of the operator’s arm during work.

❑The air inside the cabinet then takes in the aerosol particles that may have been generated and moves it away from the operator towards the HEPA filter.

❑The air moving out of the cabinet is thus, sterilized via the HEPA filters before its discharge to the environment.

Answer 22

Class I

Question 23

is a ventilated cabinet, which provides personnel, product, and environmental protection

Answer 23

Class II

Question 24

provide both kinds of protection since makeup air is also HEPA-filtered.

Answer 24

Class II

Question 25

❑The principle of operation of Class II cabinets involves a fan mounted in the top of the cabinet that draws a curtain of sterile air over the workstation where the biological products are being handled. ❑The air then moves underneath the work station and back up to the top of the cabinet before passing through the HEPA filters.

Answer 25

Class II

Question 26

❑The exhaust that moves out of the facility consists of air being drawn into the front of the cabinet underneath the work surface. ❑The air drawn in acts as a barrier against the potentially contaminated air coming back out to the operator.

Answer 26

Class II

Question 27

The alarm on/off switch. The alarm will sound when the sash is raised above the height designated on the BSC.

Answer 27

Alarm Switch

Question 28

The on/off switch for the blower motor. The blower motor controls airflow in the BSC

Answer 28

Cabinet blower switch

Question 29

A connection to the building exhaust system on top of a BSC which includes one or more openings or gaps. An audible and a visual alarm will notify the user of a potential loss in canopy containment.

Answer 29

Canopy (also called a thimble) and alarm

Question 30

The connection to the building exhaust system on top of a BSC that is air tight with no openings or gaps. Also called "hard duct."

Answer 30

Direct duct

Question 31

The large pan below the BSC work surface that retains spillage from the work area. Commonly referred to as a catch basin.

Answer 31

Drain spillage trough

Question 32

The lever that opens and closes the drain for liquid under the work surface from the drain spillage trough.

Answer 32

Drain valve

Question 33

The air vent in the work surface at the front opening of a BSC.

Answer 33

Front grille

Question 34

: A filter with a minimum biological particulate removal efficiency of 99.97%.

Answer 34

HEPA Filter

Question 35

The on/off switches for the fluorescent light and ultraviolet light in a BSC.

Answer 35

Light Switch

Question 36

The on/off switch for the power outlet inside a BSC.

Answer 36

Power outlet switch

Question 37

The gauge that reads in units and referred to as "inches of water." It is an indication of the static pressure inside of a cabinet plenum.

Answer 37

Pressure differential gauge/magnehelic gauge

Question 38

The air vent in the work surface at the back wall of the BSC

Answer 38

Rear grille

Question 39

The front sliding window of a BSC

Answer 39

Sash

Question 40

The on/off valve located on the side of a BSC and used to connect to the building vacuum system.

Answer 40

Vacuum petcock

Question 41

The work area inside a BSC.

Answer 41

Work surface

Question 42

▪Internal fan – draws room air – 75lfm (linear feet/min) velocity ▪Supply air flows through HEPA – particulate free air to the work surface

Answer 42

Class II A1

Question 43

▪Reduced turbulence ▪Reduced cross contamination ▪Downward moving air – splits into two: 1) To the front grille 2) To the rear grille

Answer 43

Class II A1

Question 44

▪30% of the air – exhaust HEPA filter ▪70% of the air – recirculates through HEPA filter back into the work zone of the cabinet

Answer 44

Class II A1

Question 45

▪Not to be used for work involving volatile toxic chemicals ▪Exhaust the air outside the building ( through use of canopy hood and filter housing )

Answer 45

Class II A1

Question 46

▪ Inflow air velocity 100lfm ▪all positive pressure contaminated plenums within the cabinet are surrounded by a negative air pressure plenum ----> ensures leakage

Answer 46

Class II A2

Question 47

▪Approximately 60% to 70% of the contaminated air is recycled and pushed back into the workstation in the chamber through the downflow HEPA filter, while the remaining 30% to 40% is exhausted through the exhaust HEPA filter

Answer 47

Class II A2

Question 48

❑ For hazardous chemicals and carcinogens ❑Inflow velocity 100lfm

Answer 48

Class II B1

Question 49

❑uses single-pass airflow to control the flow of hazardous vapors ❑divides the airflow so that the contaminated air is directed towards the exhaust system while the air between the operator and the workstation mixes with the inflow and is recirculated.

Answer 49

Class II B1

Question 50

❑The exhaust air dispersed out of the facility should be passed through the HEPA filters to provide protection to the environment. ❑These cabinets have a dedicated duct system which allows the release of the contaminated air out of the facility. ❑40% of the air ----> recirculated, 60% ---> exhausted out of the facility.

Answer 50

Class II B1

Question 51

▪Total exhaust cabinet ▪No air recirculation ▪Simultaneous biological and chemical containment

Answer 51

Class II B2

Question 52

▪Inflow air velocity 100lfm ▪Exhaust 1200 cubic feet/min of room air Expensive cabinet --> high cost of heavier gauge and higher capacity exhaust fan hence only for research

Answer 52

Class II B2

Question 53

located near the work surface, supplies HEPA-filtered air downward to the work surface.

Answer 53

supply HEPA Filter

Question 54

located near the top of the BSC, exhausts HEPA-filtered air back into the laboratory or to the outdoors through a canopy connection to the building exhaust system.

Answer 54

exhaust HEPA Filter

Question 55

is a dedicated BSC exhaust connection that incorporates one or more small openings or air gaps between the top of the BSC and the building exhaust system.

Answer 55

Canopy

Question 56

allows a BSC to exhaust noxious or toxic vapors directly from the cabinet to the outdoors. Not all Type A2 BSCs will have this.

Answer 56

Canopy

Question 57

have no within-cabinet recirculation; 100% of the exhaust is HEPA-filtered and exhausted to the outdoors.

Answer 57

Type B2 BSC

Question 58

recirculate some HEPA-filtered air into the BSC but exhausts the majority of the HEPA-filtered air to the outdoors.

Answer 58

Type B1 BSC

Question 59

Uses to work with volatile chemicals and radionuclides

Answer 59

Type 1 and Type 2 BSC

Question 60

- are leak-tight, totally enclosed but ventilated cabinets, where all air that either enters or leaves through the facility pass through a HEPA filter. ❑The cabinets are provided with rubber gloves that are attached to the system to be used during operations in the cabinet.

Answer 60

Class III

Question 61

❑The cabinet even has a transfer chamber that facilitates the sterilization of materials before they leave the glove box. ❑Even though the gloves restrict the hand movement of the operator inside the cabinet, it prevents direct contact between the operator and the samples.

Answer 61

Class III

Question 62

In Class III, the exhaust air is treated with

Answer 62

double HEPA filters

Question 63

❑Highly infectious agents, hazardous operations ❑Non opening view window ❑Passage of materials through a dunk tank

Answer 63

Class III

Question 64

❑Double door pass through box with autoclave ❑ Supply and exhaust air --> HEPA ❑Negative pressure cabinet ❑Long heavy duty rubber gloves attached in a gas tight manner to port in the cabinets

Answer 64

Class III