July 18, 2021: Pharmaceutical Interview Questions and Answers

#CleanRoomConditions, #AsBuiltAtRestInOperational, #TypesOfAirLocks, #DifferentialPressureBtweenCleanRoom, #ComparisonOfPascalsToMm, #OnlineCalculationPascalsToMm

1. What are the different clean room conditions? Explain it.

There are three conditions of clean rooms – as built, at rest and in-operation.

As built:

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Condition where the installation is complete with all services connected and functioning but with no production equipment, materials, or personnel present.

At rest:

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Condition where the installation is complete with equipment installed and operating in a manner agreed upon by the customer and supplier, but with no personnel present.

In operational:

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This condition relates to carrying out room  classification tests with the normal production process with equipment in operation, and the normal staff present in the room.

Reference: WHO Working document QAS/02.048/Rev.2

2. What are the different types of air locks? Explain it.

There are three types of air locks, Cascade airlock, Sink airlock and Bubble airlock.

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Cascade airlock: high pressure on one side of the airlock and low pressure on the other side.

Bubble Airlock: high pressure inside the airlock and low pressure on both outer sides.

Sink Airlock: low pressure inside the airlock and high pressure on both outer sides.

Reference: WHO Working document QAS/02.048/Rev.2

3. What should be the differential pressure between two adjacent clean room zones?

The most widely accepted pressure differential to achieve containment between the two adjacent zones is 15 Pa, but pressure differentials of between 5 Pa and 20 Pa could be acceptable.

Where the design pressure differential is too low and tolerances are at opposite extremities, a flow reversal can take place. E.g. where a control tolerance of ±3 Pa is specified, the implications of the upper and lower tolerances on containment should be evaluated.

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4. Comparison of pascals to mm of water?

PascalsMillimeters of waterPascalsMillimeters of waterPascalsMillimeters of water
1Pa0.10mm H2O16Pa1.63mm H2O31Pa3.16mm H2O
2Pa0.20mm H2O17Pa1.73mm H2O32Pa3.26mm H2O
3Pa0.31mm H2O18Pa1.84mm H2O33Pa3.37mm H2O
4Pa0.41mm H2O19Pa1.94mm H2O34Pa3.47mm H2O
5Pa0.51mm H2O20Pa2.04mm H2O35Pa3.57mm H2O
6Pa0.61mm H2O21Pa2.14mm H2O36Pa3.67mm H2O
7Pa0.71mm H2O22Pa2.24mm H2O37Pa3.77mm H2O
8Pa0.82mm H2O23Pa2.35mm H2O38Pa3.87mm H2O
9Pa0.92mm H2O24Pa2.45mm H2O39Pa3.98mm H2O
10Pa1.02mm H2O25Pa2.55mm H2O40Pa4.08mm H2O
11Pa1.12mm H2O26Pa2.65mm H2O41Pa4.18mm H2O
12Pa1.22mm H2O27Pa2.75mm H2O42Pa4.28mm H2O
13Pa1.33mm H2O28Pa2.86mm H2O43Pa4.38mm H2O
14Pa1.43mm H2O29Pa2.96mm H2O44Pa4.49mm H2O
15Pa1.53mm H2O30Pa3.06mm H2O45Pa4.59mm H2O
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