Section 9 - Laminar Flow Cabinets

Question 1

What is high efficiency particulate air (HEPA) filtration?

Answer 1

Process that filters microorganisms and particulates out while providing sufficient airflow to sweep aerosols and particulates out of the work area

Question 2

What are the components of a HEPA filtration system?

Answer 2

• Medium (cellulose or fiberglass)
• Separators that direct air in a uniform parallel (laminar) flow
• Frame
• Adhesive to seal medium to frame
• Gasket to seal frame to cabinet

Question 3

The HEPA filtration system is capable of removing ___% of all particulates ___ diameter or larger

Answer 3

99.97%; 0.3 um

Question 4

What is the rate of flow for a HEPA filtration system?

Answer 4

24 m/minute

Question 5

What should be done to the work surface and interior of the cabinet prior to use?

Answer 5

Wiped w/ disinfectant solution using non-shedding cloth

Question 6

Why should the space between the HEPA filter and the work area be empty?

Answer 6

To maintain laminar flow and avoid turbulence

Question 7

What is the function of a chemical fume hood?

Answer 7

• Provides operator w/ protection from gasses and vapors

- Does not protect product or environment from particulate contamination

Question 8

What is the function of a laminar flow clean bench?

Answer 8

• Provides product w/ protection from particulate contamination
• No operator protection b/c air flows toward operator
• No protection for environment

Question 9

What should not be used/done on a laminar flow clean bench?

Answer 9

• Infectious or toxic particulates

- Activities possibly generating aerosols

Question 10

What is the function of biological safety cabinets?

Answer 10

• Offers protection for product from particulate contamination
• Protects operator and environment from particulates

Question 11

What are biological safety cabinets useful for?

Answer 11

Handling infectious or toxic particulate material or aerosols

Question 12

What are the 3 classes of biological safety cabinets?

Answer 12

• Class 1 - partial containment cabinet which draws room air directly in from front and exhausts air through HEPA filter
• Class 2 - partial containment cabinets that protect product, operator, and environment from contamination

Question 13

What is protected from particulates in a class 1 biological safety cabinet?

Answer 13

Operator and environment, but not product

Question 14

What should not be used in a class 1 biological safety cabinet and why?

Answer 14

Toxic vapors or gasses b/c will pass through HEPA filter and enter environment

Question 15

What are the most common types of class 2 biological safety cabinets?

Answer 15

• Type A - exhausts into room

- Type B - exhausts outside (classified into B1, B2, and B3)

Question 16

What is exhausted air passed through in class 2 biological safety cabinets?

Answer 16

HEPA filter

Question 17

What is the air flow rate for class 2 biological safety cabinets and where does the HEPA filtered air go?

Answer 17

• Flow rate = 24 m/min

- 70% of HEPA filtered air goes into cabinet and 30% goes back into room

Question 18

What is the air flow rate for class 2 type B1 biological safety cabinets and where does the HEPA filtered air go?

Answer 18

• Flow rate = 32 m/min

- 30% of HEPA filtered air goes into cabinet and 70% is exhausted outside

Question 19

What is an advantage to class 2 type B1 biological safety cabinets?

Answer 19

• No return of air back into room

- All contaminated ducts and plenums are under negative pressure to prevent accidental contamination of room

Question 20

What is the air flow rate for class 2 type B2 biological safety cabinets and where does the HEPA filtered air go?

Answer 20

• Flow rate = 32 m/min

- 100% of HEPA filtered air is sent outside

Question 21

What is the air flow rate for class 2 type B3 biological safety cabinets and where does the HEPA filtered air go?

Answer 21

• Flow rate = 32 m/min
• Same design as type A but instead of exhausted air going into the room, it goes outside
• All contaminated ducts and plenums under negative pressure

Question 22

What is the function of a barrier isolator?

Answer 22

• Provides physical barrier btwn work and work process

- Supplies and materials passed through airlock system

Question 23

Where are isolators found and why?

Answer 23

In some hospital pharmacies to comply w/ USP 797 as an alternative to a clean room

Question 24

What is needed w/in a clean room?

Answer 24

• Entire ceiling or one wall composed of HEPA filter panels w/ air flow of 24 m/min
• Have been classified by allowable number of particles of 0.5 um or larger per cubic foot of air

Question 25

What is the requirement for a class 100 room?

Answer 25

May not have particle counts exceeding 100 particles of size 0.5 um per cubic foot

Question 26

What are the 3 classes of clean rooms for pharmaceutical manufacturing?

Answer 26

Class 100, class 10,000 and class 100,000

Question 27

What is the entrance like for a clean room and what must staff wear?

Answer 27

• Entrance is air-lock or double door entry

- Staff generally wear non-shedding garments which cover body including head and feet

Question 28

What type of pressure are clean rooms maintained under and why? Which rooms have the highest pressure?

Answer 28

• Positive pressure to prevent entrance of air-borne particulates
• Highest pressure in cleanest rooms

Question 29

How is a clean room monitored to make sure limit of particulates is not exceeded?

Answer 29

Automated monitors pass measured volume of air through a narrow chamber which contains a light source on one side and light detector on the other

Question 30

How are microbial counts conducted for a clean room?

Answer 30

Settle plates or air impingers

Question 31

How are settle plates conducted for clean rooms?

Answer 31

Petrie dishes of nutrient agar are exposed to air for 20 minutes, incubated, and number of colonies is counted

Question 32

Are laminar flow cabinets a good substitute for aseptic technique?

Answer 32

No