Equipment

Question 1

A HEPA filter removes particles from the air by

Answer 1

interception, inertial impaction and diffusion.

Question 2

HEPA (P100) filter efficiency

Answer 2

99. 97 percent efficient for

0. 3 micrometer (µm) particles at a flow rate of 85 liters per minute (lpm)

Question 3

N95 efficiency

Answer 3

95 percent efficient against 0.3 µm particles at 85 lpm

Question 4

BSC certification provides assurance of

Answer 4

– balance of inflow and exhaust air
– distribution of air onto work surface
– integrity of cabinet
– function of electrical and physical features (optional
field test)

Question 5

BSC airflow smoke patterns tests

Answer 5

– Airflow along entire perimeter inward?
– Airflow in work area downward? Dead spots?
Refluxing?
– Ambient air passing onto or over work
surface?
– Refluxing outward at window gasket and
seals?

Question 6

HEPA Filter Leak Test DOP alternatives

Answer 6

polyalpha olefin (PAO), di[2-ethylhexyl] sebecate,
PEG, light mineral oil (medical grade)

Question 7

Class I BSC

Answer 7

• Similar to fume hood with HEPA exhaust
• No product protection

• If externally vented okay for volatile chem /
radioisotopes
• House sonicators, harvesters, etc.
• May be suitable for BSL 1,2 or 3

Question 8

Class II Type A1 BSC lf/m

Answer 8

75 lf/m face velocity

Question 9

Class I BSC lf/m

Answer 9

75 lf/m face velocity

Question 10

Class II Type A1 BSC general

Answer 10

• 70% recirc. air, 30% exhausted (thru HEPA)
• Halogen gas test to verify positive pressure
plenums are leakproof
• Exhaust to room or thimble connected to
external exhaust duct
– Audible & visual alarms for exhaust system
failure when thimble connected
• No volatiles

Question 11

Class II Type A2 BSC general

Answer 11

• formerly Type B3

• Same as Type A1, but positive pressure
contaminated plenums surrounded by
negative pressure plenum

• Suitable for volatile toxic chems and
radionuclides (minute amounts, if
exhausted to the outside)

Question 12

Class II Type A2 BSC lf/m

Answer 12

100 lf/m face velocity

Question 13

Class II Type B BSCs

general

Answer 13

All Class II Type B BSCs are hard-ducted to an external exhaust system

Question 14

Class II Type B BSCs

lf/m

Answer 14

100 lf/m

Question 15

Class II, Type B1

Answer 15

– Positive pressure plenums (filtered air)
– All contaminated air in neg. pressure plenum
– Small amts of volatile rad/toxic chems in rear of hood
(directly exhausted)
-emergency power supply to exhaust blower
– Interlock to prevent supply blower operation when
exhaust is insufficient & alarms

Question 16

Class II, Type B1 Recirc/Exhaust %

Answer 16

– 30% recirc air, 70% exhaust, thru HEPA

Question 17

Cell Sorters risk

Answer 17

• Risk is high with unfixed

Question 18

Cell Sorters containment

Answer 18

BSL3 recommended unless in containment device
• Dependent on risk assessment – BSL2 with BSL3 practices
• Wear additional PPE (e.g. PAPR, N-95, wrap around gown)
and run in a negative pressure facility