Airlocks
Presented by Gordon Farquharson
August 2015
Agenda
Regulatory expectation
Different functional configurations
Good design practice
What often goes wrong
Qualification of airlock performance
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Regulatory expectation/guidance
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PIC/S Annex 1 guidance
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PIC/S Annex 3 guidance
PIC/S Annex 5 guidance
PIC/S Annex 10 guidance
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PIC/S Glossary
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WHO HVAC OSD supplementary Guidance
Airlocks
The Dp values are indicative – they aren’t a requirement
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Biosafety Regulations
• For the containment of human & animal pathogens.
• There are different regulations in each nation, but the principles
are all similar.
• Facility design impact:
– Conflict – Containing Hazards vs Protecting Processes
-ve pressure
vs
+ve pressure
Let’s look at the essential features of the biosafety regulations.
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Biosafety levels: BL-1
Laboratory
Practices
Special Practices
Containment
Equipment
Laboratory
Facility
Access limited
Leak-proof container for
off-site decontamination
None
Easily cleaned
Daily and after-spill
decontamination
Pest control
Waste
decontaminated
Screens in
windows
No mouth pipette
Personal Wash
Minimise aerosols
Uniform
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Hand wash
sink
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Biosafety levels: BL-2
Laboratory
Practices
Special Practices
Same as BL-1
Same as BL-1 except
Principal investigator limits
Can also
perform BL-1 if access
Policies and procedures for
isolated
access
Hazard warning sign if special
procedures
Special gowning for laboratory
No spare animals in laboratory
Avoid skin cross contamination
Waste decontamination
Limited use of syringes
Report spills to NIH
Worker blood samples
Biosafety manual
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Containment
Equipment
Laboratory
Facility
Biosafety
cabinets (Class
I, II) if aerosols
or high number
of organisms
Same as BL-1
Autoclave for
waste
decontaminatio
n
Biosafety levels: BL-3
Laboratory
Practices
Special Practices
Containment
Equipment
Laboratory Facility
Same as BL-2
Same as BL-2 and:
Same as BL-2
No entry
under age 16
Doors closed
Lesser
organisms in
same
laboratory
must follow
BL-3
Hazard sign required
Biosafety
cabinets (Class
I, II, III) or
physical
containment
devices
More limits on access
No open work
Clean-up when finished
Gowning
decontamination
Airlock or gown room
access
Sink near door has nocontact faucet
Closed/sealed windows
Self-closing doors
Mask/respirator
Special animal cages
HEPA on vacuum
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Separated from
building flow
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Ducted exhaust
BSC exhaust outdoors
Biosafety levels: BL-4
Laboratroy
Practices
Special Practices
Containment
Equipment
Laboratory Facility
Same as BL-3
Double container
for waste
Class III BSC
Separate building or isolated
zone
Sealed internal shell, can be
decontaminated
Flooded floor drain traps
connected to waste
decontamination
HEPA on vents and drains
Minimize dust surfaces
Seamless bench tops
Dedicated central vacuum
with HEPA at point of use
Backflow prevention for
process fluids
Doors self closing and
locking
Break resistant windows
Class I or II
Decontaminate
everything but
BSC using one
product leaving the piece suit with
laboratory
ventilation
Access tightly
controlled, locked
doors, logbook
Emergency
protocols
Access in/out
through shower
rooms
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Biosafety levels: BL-4 cont…
Laboratory
Practices
Special Practices
Containment Laboratory Facility
Equipment
Same as
BL-3
No street clothing,
special uniform
Class III BSC Double door autoclave or
dunk tank for
Class I or II decontamination out
Hazard signs
Decontaminate
incoming materials,
airlock access
No spare materials,
clothing, animal
BSC using
one piece
suit with
ventilation
Heat decontamination for
liquid wastes
Shower drain and toilet drain
disinfection
Dedicated HVAC with DP
monitoring
Worker health
monitoring
HEPA exhaust
Class III BSC exhaust to
outdoors through HEPA
One-piece suit, suit-up area
Chemical shower for suit
decontamination, redundant
HEPA exhaust
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Airlock functional configurations
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Objective of airlocks
Before we look at different conceptual options, we need to
understand some basics:
• To maintain room differential pressure as personnel and/or
materials enter or leave.
• To maintain cleanliness differentials.
• To provide an intermediate zone between rooms to implement a
status change:
– Gowning / Un-gowning of personal. Personnel changing
rooms are special kinds of airlock.
– Cleaning / Decontamination of materiel surfaces.
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Cleanroom application for the control
of Dp and cleanliness
Doors closed
Corridor Grade D +
A/L C ++
Room Grade C +++
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When all doors closed:
• Door closed pressures
maintained.
• Corridor is Grade D.
• A/L must be at cleaner
Grade C.
• Room is Grade C.
Cleanroom application for the control
of Dp and cleanliness
Grade D Door open
Corridor Grade D +
A/L D +
Room Grade C +++
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When Grade D side door is open:
• A/L and Corridor pressures
equalise.
• Grade C room pressure is
maintained.
• A/L assumed to be Grade
D = Corridor.
• Room maintains Grade C.
Cleanroom application for the control
of Dp and cleanliness
Grade C Door open
Corridor Grade D +
A/L C +++
Room Grade C +++
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When Grade C side door is open:
• A/L and Room pressures
equalise.
• Grade C room pressure is
maintained.
• A/L assumed to be Grade
C = Room.
• Room maintains Grade D.
What are the different types of Airlock
used in the Pharma world?
•
•
•
•
Cascading Pressure Airlock
Pressure Bubble Airlock
Pressure Sink Airlock
Potent Compound Airlock
del Valle, Manuel A. PE “Design and Operation of Biotechnology: Design and
Operation of Biopharmaceutical Airlocks” CleanRooms February 2000
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Cascading pressure airlock
+
Clean Area
+ 30
P
aTypically, an
equal amount of
air is supplied to
and returned
from the airlock
³ 15 Pa
Less Clean Corridor
+15
0.05 in H2O = 12.5 Pascals
Pressurized air cascades from a clean to a less clean adjacent area
del Valle, Manuel A. PE “Design and Operation of Biotechnology: Design and Operation of
Biopharmaceutical Airlocks” CleanRooms February 2000
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Pressure Bubble Airlock
Contained
- Clean Area
³.15
Pa
+
+
³.15
-15
Clean conditioned
air is used to
pressurize the
airlock.
+15
Pa
Less Clean Corridor
0
0.05 in H2O = 12.5 Pascals
Cleaned conditioned air is used to pressurize the airlock. This air
dissipates through the airlock doors to adjacent areas.
del Valle, Manuel A. PE “Design and Operation of Biotechnology: Design and Operation
of Biopharmaceutical Airlocks” CleanRooms February 2000
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Pressure sink airlock
Contained
+ Clean Area
³15
+15
Pa
-
0
³ 15 Pa
+
Less Clean Corridor
All of the air that
infiltrates into the
airlock and all of
the supply air is
exhausted
+15
0.05 in H2O = 12.5 Pascals
Negative pressure is maintained relative to the adjacent areas and all
of the air entering the room is exhausted.
del Valle, Manuel A. PE “Design and Operation of Biotechnology: Design and Operation
of Biopharmaceutical Airlocks” CleanRooms February 2000
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Potent Compound Airlock
+
³15 Pa
0
Potent Compound
Clean Area
+
³.30 Pa
-
-
-
+ +15
Clean conditioned air is
used to pressurize the
airlock off of the corridor.
There is no return. All of
the air that infiltrates into
the airlock off the Potent
Compound
Clean Area
and all of the
³.15Pa supply air is
exhausted
-15
-
.00
Less Clean Corridor
0.05 in H2O = 12.5 Pascals
A two-cell combination of the pressure bubble and pressure sink
airlocks
del Valle, Manuel A. PE “Design and Operation of Biotechnology: Design and Operation of
Biopharmaceutical Airlocks” CleanRooms February 2000
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Estimation of leakage
Important for any HVAC pressurisation design
•
•
•
•
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Designer must estimate the known leakage rate
Designer must allow for any unknown leakage rates
Doors should be the main leakage path
Leakage rate through small gaps can be determined from:
– Q = 0.827 x A x (DP)0.5
– Where:
› Q = leakage rate m3/sec
› A = leakage area m2
› and, DP = differential pressure between spaces Pa
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Estimation of leakage around door cracks
Door Size
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Leakage (Iitre/s) at Differential Pressure (Pa)
5
10
15
20
25
30
35
40
45
Single
24
35
42
49
55
60
65
69
73
Double
53
74
91
105
118
129
140
149
158
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Airlock Good Design Practice
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Good airlock practice – Check list
 Describe the function:
 Cleanliness levels:
Define levels.
Ventilation & air filtration
requirement.
••Internal
furniture & equipment.
Recovery
time.
•
•
• Cleaning / decontamination ;
gowning; etc.
 Adequate space:
•
Internal furniture & equipment.
 Interlocks:
Choose types:
• Electromechanical.
• Traffic lights.
 Pressurisation &
pressure control objectives.
 Time delays.
 Leak tightness.
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Things that go wrong with airlocks
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Common airlock problems
•
•
•
•
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Door leakage prevents adequate room pressure maintenance.
Internal space too small.
Recovery time not adequately characterised.
Changing / Gowning rooms:
– Inadequate space.
– Process not well defined.
– Inadequate segregation of different phases of change
process.
› Separation of entry & exit (Spatial or Temporal)
− Failure to comply with Annex 1 “final part of change room
should be the same grade as the space accessed”.
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Qualification of airlock performance
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Airlock performance qualification (PQ)
To prove the function:
• Confirm supply & return airflow volume.
• Test pressure stability:
1. Open each door in turn, and confirm that the overall
critical room/zone pressure regime remains within
specification (some small changes should be anticipated
because the leakage path resistance for the higher
pressure room is reduced when individual doors are
open.
2. Open individual doors to different airlocks to mimic
normal simultaneous use worst-case situations.
• Cleanliness classification
A. At rest
B. Operational
• Recovery time to qualify interlock time delays.
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Thank you for your time.
Questions?
Gordon Farquharson
Executive Consultant
gordon.farquharson@pharmout.net
www.pharmout.net
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