Section 9 - Laminar Flow Cabinets Flashcards
What is high efficiency particulate air (HEPA) filtration?
Process that filters microorganisms and particulates out while providing sufficient airflow to sweep aerosols and particulates out of the work area
What are the components of a HEPA filtration system?
- 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
The HEPA filtration system is capable of removing ___% of all particulates ___ diameter or larger
99.97%; 0.3 um
What is the rate of flow for a HEPA filtration system?
24 m/minute
What should be done to the work surface and interior of the cabinet prior to use?
Wiped w/ disinfectant solution using non-shedding cloth
Why should the space between the HEPA filter and the work area be empty?
To maintain laminar flow and avoid turbulence
What is the function of a chemical fume hood?
- Provides operator w/ protection from gasses and vapors
- Does not protect product or environment from particulate contamination
What is the function of a laminar flow clean bench?
- Provides product w/ protection from particulate contamination
- No operator protection b/c air flows toward operator
- No protection for environment
What should not be used/done on a laminar flow clean bench?
- Infectious or toxic particulates
- Activities possibly generating aerosols
What is the function of biological safety cabinets?
- Offers protection for product from particulate contamination
- Protects operator and environment from particulates
What are biological safety cabinets useful for?
Handling infectious or toxic particulate material or aerosols
What are the 3 classes of biological safety cabinets?
- 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
What is protected from particulates in a class 1 biological safety cabinet?
Operator and environment, but not product
What should not be used in a class 1 biological safety cabinet and why?
Toxic vapors or gasses b/c will pass through HEPA filter and enter environment
What are the most common types of class 2 biological safety cabinets?
- Type A - exhausts into room
- Type B - exhausts outside (classified into B1, B2, and B3)
What is exhausted air passed through in class 2 biological safety cabinets?
HEPA filter
What is the air flow rate for class 2 biological safety cabinets and where does the HEPA filtered air go?
- Flow rate = 24 m/min
- 70% of HEPA filtered air goes into cabinet and 30% goes back into room
What is the air flow rate for class 2 type B1 biological safety cabinets and where does the HEPA filtered air go?
- Flow rate = 32 m/min
- 30% of HEPA filtered air goes into cabinet and 70% is exhausted outside
What is an advantage to class 2 type B1 biological safety cabinets?
- No return of air back into room
- All contaminated ducts and plenums are under negative pressure to prevent accidental contamination of room
What is the air flow rate for class 2 type B2 biological safety cabinets and where does the HEPA filtered air go?
- Flow rate = 32 m/min
- 100% of HEPA filtered air is sent outside
What is the air flow rate for class 2 type B3 biological safety cabinets and where does the HEPA filtered air go?
- 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
What is the function of a barrier isolator?
- Provides physical barrier btwn work and work process
- Supplies and materials passed through airlock system
Where are isolators found and why?
In some hospital pharmacies to comply w/ USP 797 as an alternative to a clean room
What is needed w/in a clean room?
- 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
What is the requirement for a class 100 room?
May not have particle counts exceeding 100 particles of size 0.5 um per cubic foot
What are the 3 classes of clean rooms for pharmaceutical manufacturing?
Class 100, class 10,000 and class 100,000
What is the entrance like for a clean room and what must staff wear?
- Entrance is air-lock or double door entry
- Staff generally wear non-shedding garments which cover body including head and feet
What type of pressure are clean rooms maintained under and why? Which rooms have the highest pressure?
- Positive pressure to prevent entrance of air-borne particulates
- Highest pressure in cleanest rooms
How is a clean room monitored to make sure limit of particulates is not exceeded?
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
How are microbial counts conducted for a clean room?
Settle plates or air impingers
How are settle plates conducted for clean rooms?
Petrie dishes of nutrient agar are exposed to air for 20 minutes, incubated, and number of colonies is counted
Are laminar flow cabinets a good substitute for aseptic technique?
No
