Chapter 12
Transfer
Procedures
By the end of this chapter,
you will be able to:
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The Transfer Process
Explain the term transfer process
The transfer process is the process used when
anything is transferred from an area of lower
environmental grade to one of higher standard.
Name two types of sanitisation
methods often used
It isn’t just the transfer of products to the
critical zone and includes transfer of other
items such as the examples below.
Describe the spray and
wipe technique
Explain the transfer process and
give some examples of items
that may be transferred
Introduction
This chapter examines techniques used to
transfer items into clean rooms and critical work
zones. We will look at how to effectively use the
spray and wipe technique and how we physically
transfer items using trays and hatches.
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Equipment
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Bin liners
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Clean room furniture, e.g. trolleys,
stools, portable benches
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Cardboard boxes or containers
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Sharps bins
Important! The transfer process involves
complete surface disinfection prior to the
introduction of an item into hatches of a clean
room or isolator. The contact time should
be clearly stated in the SOP, checked and
maintained in practice.
Chapter 12: Transfer Procedures
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Aseptic Processing
Sanitisation
(This is the term used in the pharmaceutical industry to
describe cleaning and decontamination)
Product components must be sanitised as
part of the transfer process using approved
sterile agents.
Sanitisation is generally done in one of 2 ways:
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Spray and wipe
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Gas sanitisation.
For the sanitisation process to work effectively
against micro-organisms, starting materials are
sprayed and wiped.
The usual procedure is to spray, wipe the
surface then spray again. However as long as
one decontamination includes a spray and
wipe combination this is satisfactory.
Alcohol solutions are usually used for the
spraying process. It has been tried and tested
over many years and it rapidly destroys a wide
range of micro-organisms.
The most common alcohols used are 70% v/v
ethanol (sometimes referred to as 70/30 ethanol
or IMS) or isopropyl alcohol 70% or IPA.
For maximum effectiveness the alcohol
needs a contact time of 2 minutes. Alcohol
evaporates quickly to leaves no residues which
makes it suitable to use with most surfaces.
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Chapter 12: Transfer Procedures
A clean part of the wipe must be used each
time it is wiped across the surface.
Chapter 12
Transfer Procedures
Spray and Wipe
Here is a summary of the advantages and disadvantages of spraying and wiping as stand alone activities.
Spraying
Advantages
Disadvantages
Quick
High vapour levels
Easy
Dependant on operator performance
Gives good coverage
Spores not killed
(although they may be rinsed off)
Can be controlled so packaging is not over
wetted or damaged
Wiping
Advantages
Disadvantages
Spores and particulates physically removed
from the surface
High dependency on operator performance
Easy
Wipes need to be turned
and changed frequently
Lower vapour levels
Wipes need to be stored correctly
So you can see that spraying or wiping by
itself isn’t as effective as combining the
two operations.
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To carry out the disinfection of assembled
work, the operator should be gowned
correctly.
The spray and wipe method is very dependent
on good practice from the operator so it is vital
that good training and validation takes place.
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Staff should wear disinfected gloves to carry
out the transfer process.
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Check gloves frequently for holes and tears
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Spray gloves frequently
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Remember to immediately apply alcoholic
hand rub as soon as gloves are removed.
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Aseptic Processing
Gas Sanitisation
Isolators and starting materials can be
sanitised with a gaseous agent, usually
hydrogen peroxide or peracetic acid.
Clean and disinfect work surfaces to be used
Disinfect and wipe a second work tray to be used
NB-Units may also use an autoclave sterilised tray
An example of a gassing isolator with the front
screen open
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Gas sanitisation involves the vaporisation
of the gas into the cabinet using a specialist
machine.
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Once the whole of the cabinet has been
filled with the gas and all surfaces covered,
the machine switches to pumping clean
air through.
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It is this process of air removing the gas
from the surface that sanitises it.
Effective gaseous biocides include:
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Ethylene oxide (not used in isolators-it can
be dangerous and explosive)
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Formaldehyde vapour (rarely used for
isolators because of toxicity issues)
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Peracetic acid vapour
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Hydrogen peroxide vapour
All the items should be separated into single
units and vial caps and infusion wrappers
removed, depending on your local procedure.
All components should be free from dirt, dust,
cracks or chips.
Items should be sprayed and wiped to ensure
that all surfaces are wetted.
Transferring components
Checks! Before the sanitisation process begins
all items in the tray should be checked to
ensure that they match with the assembly
check already carried out. (See Chapter 11)
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Chapter 12: Transfer Procedures
Each item should be taken in turn and all
surfaces wiped with sterile alcohol wipes using
a uniform wiping action.
Chapter 12
Transfer Procedures
Note: The same surface of the wipe should
not be used twice.
You should not use a rubbing or circular
action! (You are not cleaning windows!).
Place wiped items into the second tray
Isolator hatches inner surfaces need to be
disinfected using spray/wipe before a tray
is placed inside.
When all the items have been wiped and
placed in the second tray the whole tray and
contents should be oversprayed as it is moved
into the clean room hatch. Don’t forget to
spray the base of the tray.
Remember to spray the tray surface that your
hand was last in contact with.
The Isolator transfer hatches are usually timed
through a control panel.
The transfer hatches inner surfaces need to be
disinfected using spray/wipe before the tray is
placed inside.
Remember. During the transfer process you
should pay particular attention to the following:
The transfer hatch door should then be closed
and the tray left in the hatch for 2 minutes
minimum contact time.
Note: If your hands touch anywhere on the
hatch, then you must spray that too!
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Paper based products harbour more
micro-organisms than plastic ones.
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Labels can lift and expose the adhesive
at a later stage (glue is a known source of
microbial contamination).
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Edges, folds and creases need to be
straightened and wiped to ensure efficient
sanitisation.
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All surfaces should be sufficiently
wet-not soaked
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The worksheet should be intact and sealed
in a plastic bag. Operators must be able
to read it!
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Spray your gloves
frequently
Chapter 12: Transfer Procedures
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Aseptic Processing
Summary of the transfer process
Transfer to Critical Zone
This is the transfer from the hatch into the
critical zone.
The critical zone is the controlled workspace
where aseptic manipulation takes place
Two stages in sanitisation will have taken place
before transfer:
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Primary disinfection using wiping and
spraying in the support rooms.
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Secondary disinfection as part of the
transfer process.
Contact Time
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The tray must also have been left for at
least 2 minutes in the transfer hatch.
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Sufficient contact time must be allowed
during all parts of the sanitisation process.
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Chapter 12: Transfer Procedures
The tray is removed from the transfer hatch
and the tray and contents are sprayed
before placing onto the Laminar Air Flow
Cabinet surface.
Chapter 12
Transfer Procedures
In the isolator unit the container has been
sprayed into the transfer hatch and is waiting
for transfer into the critical zone
Transfer Out of Critical Zone
Before transfer out of the critical zone the
following should be observed:
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Waste should be disposed of by following
the correct procedure.
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On completion of a product all items for
checking must be reconciled, and placed in
the transfer tray.
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Final products should be wiped to remove
any external chemical contamination before
leaving the isolator or LAFC.
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Components for checking and finished
products must be kept together.
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Items leaving the critical zone are not
subject to a time delay and can be placed
directly in the hatch.
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If final product is placed in the same hatch
as when entering the room, make sure
there are no incoming products in the
hatch.
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All products should be moved to labelling
and checking
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All surfaces within the critical zone should
be cleaned and wiped with alcohol.
Chapter 12: Transfer Procedures
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Aseptic Processing
Test Yourself
Can you remember what you should pay particular attention to during the transfer process?
Test Yourself
Fill in the blanks in the following sentence:
The critical zone is ……………......……………………… where ……................................…….
…………………….................................................……. takes place.
Workflow
There may be more than one product being
made at a time in an aseptic unit.
Products need to be separated in some way
so that there is no confusion about the starting
materials, components, worksheets and labels
which could lead to confusion and errors.
All components for the product should be
assembled prior to processing
Manipulations should be undertaken in
one operation.
There should not be a break in the process
to add further components especially in
the critical zone. (Remember: The critical
zone is the controlled space where aseptic
manipulation takes place.)
Trays should not be overfilled (boxes with lids
can be used as an alternative to prevent items
falling out).
Labels should be adequately segregated and
reconciled to avoid mislabelling.
If the same facilities are used for different
product types:
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Activities must be segregated by time.
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Specific cleaning arrangements should be
set up to avoid cross contamination.
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Consideration should be given to
permanently separating product types by the
use of a separate cleanrooms or isolators.
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Chapter 12: Transfer Procedures
When all the products are completed they
should be identified by a label.
Note: Products made at the same time (using
the same worksheet) should be kept together.
Chapter 12
Transfer Procedures
Activity
Make sure you watch the following videos at:
http://www.medslearning.leeds.ac.uk/pages/aseptics/videos.html
and then refer to your local procedures:
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Spray and Wipe-Spraying video 6
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Spray and Wipe-Wiping video 7
If there are any variations in your local procedures, make a note of them below and discuss
with your supervisor.
Spraying:
Wiping:
Chapter 12: Transfer Procedures
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Aseptic Processing
Questions
Q1
What are the advantages of the spray and wipe processes?
Spraying:
Wiping:
(4)
Q2
(3)
Describe how the Gas Sanitisation process works.
(4)
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Chapter 12: Transfer Procedures
Chapter 12
Transfer Procedures
Q3
When transferring items into the clean room, what are the 6 stages of the transfer process?
1.
2.
3.
4.
5.
6.
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Aseptic Processing
Q4
Why should products of different types be segregated?
(2)
Q5
How long should the tray be left in the transfer hatch when transferring into and out of
the critical zone?
Into critical zone:
Out of critical zone:
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Chapter 12: Transfer Procedures