Clean room design

Question 1

why is aseptic manufacturing more demanding

Answer 1

there is no final sterilisation step

Question 2

where are most sterile manufacturing processes performed

Answer 2

in clean rooms

Question 3

give examples of sources of contamination

Answer 3

bacteria, fungi, viruses
from skin, wounds, cleaning materials, packaging, poor disinfection, poor hygiene

Question 4

what are clean rooms

Answer 4

self contained facilities with dedicated ventilation systems
- control air quality, temperature and humidity

Question 5

how is air filtered in a clean room

Answer 5

air filtered by High efficiency particulate air (HEPA) filters

Question 6

describe the air handling in clean rooms

Answer 6

1. dirty air from the surrounding area is prevented from entering the clean room by controlling air pressure
2. cleanest room at highest (positive) pressure
   - air flows from the cleanest to dirtiest areas

Question 7

name the 2 categories clean rooms fall under in terms of air flow

Answer 7

unidirectional and non unidirectional

Question 8

how is airflow controlled in a unidirectional clean room

Answer 8

1. normally have vertical airflow- air flows downwards through HEPA filters located in ceiling
2. air is extracted through perforated flooring or grilles mounted at floor level

Question 9

how is airflow controlled in a non unidirectional clean room

Answer 9

1. air flows from HEPA filters located in various positions and returned through opposite locations
2. air flow may be turbulent in nature

Question 10

describe the internal room design of a clean room

Answer 10

1. floors, walls and ceilings should be made of a smooth, impervious material and rounded corners
2. all doors should be controlled to prevent unwanted flow of air from one area to another
3. there should be no shelves, window ledges or door frames
4. there should be no water sources, sinks or drains

Question 11

describe the features that should be found in the wash room

Answer 11

1. hand washing facilities should be available external to changing rooms
2. taps should be elbow or foot operated

Question 12

what are particle loads

Answer 12

• highest standards of environmental control are included in the design of clean rooms
• there are a maximum number of particles allowed in clean rooms at rest and during operation

Question 13

give an example of a clean room Grade A

Answer 13

Laminar flow cabinets and isolators

Question 14

give an example of a clean room grade B

Answer 14

the aseptic room

Question 15

give an example of a clean room grade C

Answer 15

the preparation room

Question 16

give an example of a clean room grade D

Answer 16

support rooms

Question 17

what is work zone 1

Answer 17

area where aseptic preparation is actually carried out
- laminar air flow cabinets are used during aseptic processing to protect products from contamination

Question 18

what is work zone 2

Answer 18

• horizontal laminar flow- filters are at the back of units and air streams over the critical zone towards the operator
• vertical laminar flow- filters are above the work surface and force clean air downwards in parallel streams

Question 19

what is work zone 3

Answer 19

• isolators are a clean environment in themselves and should also be sited within a clean room
• isolators act as a physical barrier between the product and the operator

Question 20

what is work zone 4

Answer 20

• most commonly used isolators are either positive pressure or negative pressure isolators
• positive pressure protects product and operator
• negative pressure gives a greater operator protection, but less protection for the product

Question 21

outline ways of contamination control

Answer 21

1. personal hygiene- hand washing
2. general hygiene- outside shoes shouldn’t be brought into a clean room
   - only approved clean room clothing is allowed
3. cleaning and disinfecting- typical cleaning schedule
   - horizontal surfaces attract more contamination than vertical ones
   - lower surfaces attract more contamination than higher ones
   - cleaning should occur at end of working day