From
The FRAVALET™ Company Limited
Innovation in Health Care Delivery
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
KI-DISCUS
A summary
of the basic
steps to be
taken in
performing a
KI-DISCUS
containment
test
Presented by
Professor Raymond Clark OBE
CEng FSEE and
Professor M. Leonardo de
Calcina-Goff FSEE FBPA
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
KI-DISCUS
Containment Testing System
KI-DISCUS is manufactured by:
Containment Technology Limited
9 Telford Road
Ferndown Industrial Estate
Wimborne
Dorset
BH21 7QW
United Kingdom
Managing Director David Pollington
Telephone: + 44 (0) 1202 870189
Fax: + 44 (0) 1202 870212
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
BIOLOGICAL SAFETY - relies very much on good safety
cabinets and other LEV systems
To provide worker and
environmental protection
the air flows at the front
apertures of open fronted
containment facilities
must adequately contain
potentially pathogenic
aerosols that may be
generated in the working
area.
This is a requirement of
Standards and
Regulatory Authorities
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Flow visualisation and air velocity measurements
complement safety cabinet performance assessment but
cannot take the place of containment tests
The sequence of
performance
tests for the front
aperture is:
1. Flow
visualisation
2. Air velocity
measurement
1
2
3. Containment
to measure
OPERATOR
PROTECTION
FACTOR
Professor R. P. Clark & M. L. de Calcina-Goff
3
The FRAVALET Company Limited
Schlieren flow visualisation puts containment on the map
In the 1970’s Schlieren
cine-photography
dramatically identified
poor performing cabinets
where potentially
contaminated air would
spill out of the cabinet and
surround the worker
These studies highlighted the
need for tests to measure
containment or “OPERATOR
PROTECTION”
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Development of containment tests
Originally a
microbiological test was
used with spores or
bacteria sprayed
towards the front
aperture
However, this produced
contamination and
could be dangerous
Another easy and safe test
was needed and KI-DISCUS
was developed
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
How to carry out KI-DISCUS
containment tests
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
The directions given here apply equally to Class I and II safety
cabinets as well as fumecupboards, open fronted cabinets for
radiopharmaceutical and cytotoxic work etc.
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
First make sure that the cabinet or cupboard to be tested has been
properly decontaminated according to regulatory authority
requirements (COSHH in the UK)
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Wheel the KI-DISCUS equipment to the front of the cabinet to
be tested and disassemble the various parts of the trolley
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
It is important to find a clean, dry bench top away from the
cabinet for the filter development equipment
Lay out the two small glass dishes, one
filled with palladium chloride and the
other with distilled water, together with
the filter papers (to dry the membranes
from the samplers), the magnifier and 3
pairs of tweezers
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Return to the cabinet and begin to assemble the components at
the front aperture
The trolley is placed at the centre line of
the aperture. The artificial arm is
assembled and placed in the circular
support in the air suction tube mounted in
the base of the KI-DISCUS trolley
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
The suction tube is next adjusted in height so that the artificial
arm is level
The spirit level built
into the end section of
the arm indicates
when it is level
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
The air samplers are next positioned at the aperture
Two air samplers are placed
on the spigots on either side
of the arm. The support for
holding the upper two
samplers is assembled and
the samplers placed in the
prescribed positions. The air
hoses are connected to the
suction take off points in the
lower part of the trolley.
The air samplers are placed between 150-160mm
from the plane of the aperture. The openings of the
upper 2 are placed level with the top of the aperture
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
KI-Discus arrangement - Class I cabinet
C
L
150-160
155
155
65-75
100
150
150
>250
Professor R. P. Clark & M. L. de Calcina-Goff
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
KI-Discus arrangement - Class II cabinet
C
L
100
155
150-160
155
65-75
150
150
Professor R. P. Clark & M. L. de Calcina-Goff
>250
The FRAVALET Company Limited
The spinning disc generator is next positioned according to the
type of cabinet being tested
For a Class I cabinet or fume cupboard the
generator disc is placed centrally under the arm
with the disc edge 100mm inside the cabinet as
measured from the plane of the aperture
For a Class II safety cabinet the
spinning disc is placed level with
the top of the aperture and again
100mm inside the cabinet
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
The air samplers are next loaded with the filter membranes
The filter loading
may be done
either with the
samplers in
position in front of
the aperture or
with them taken to
a bench away
from the cabinet
To avoid contamination it is most important that one pair of
tweezers is dedicated to loading the membranes into the air
samplers. Care must be taken to ensure that the blue
“separator” discs between the white membranes are removed
before the membranes are placed in the samplers
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
The air flow through the samplers is next adjusted
Once the samplers are loaded and placed
on their suction tubes, the air flow through
them is adjusted using the barrel valve on
each sampler. The suction pump is
switched on and the pressure gauge is
attached to the measuring point on each
sampler in turn
The barrel valve is adjusted to give a reading of 8 ins wg
(200mm wg) which ensures the correct air flow rate through
the sampler orifice of 100 litres/minute
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Setting up the spinning disc generator
The time for the peristaltic pump
to deliver 20ml will previously
have been measured and the run
time set on the digital timer.This
ensures that when the start button
is pressed exactly 20 ml of KI
will be dispensed on to the
spinning disc for aerosolization
To prime the tubing to the spinning
disc, on MANUAL CYCLE, switch
on the pump until KI has
completely filled the supply line to
the spinning disc.
Once everything is set up, the test
begins by pressing the automatic
start button
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
Developing the filter membranes after the test
At the end of a test the
spinning disc and air
samplers will
automatically stop in the
correct sequence.
Remove the filter
membranes from the
samplers using the sharp
pointed tweezers
(designated solely for
this purpose)
Without wetting the tweezers place the
filter into the palladium iodide solution
with the surface on which any KI
landed, upwards
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
After some 20 seconds the development process will be
complete
Use a third pair of
tweezers (again
designated solely
for this purpose) to
remove the filter
membrane from the
palladium chloride .
When the filter membrane is
fully impregnated with
palladium chloride the chemical
reaction turning KI into
palladium iodide will be
complete
Professor R. P. Clark & M. L. de Calcina-Goff
Rinse the filter membrane in water in the
second glass dish and lay it to dry on the
filter paper
The FRAVALET Company Limited
The magnifier is used to identify and count the number (n) of
grey/brown dots on each filter membrane
The protection factor
(PF) is evaluated from
the formula:
PF = (62 x 105) ÷ n
If there are more than 62
spots on ANY ONE filter
membrane then the test
has failed and the
protection factor is less
than 105
The convention is that membranes from all sampling
heads must EACH have fewer than 62 dots for the
cabinet to pass the test
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
At the end of a series of tests the spinning disc and artificial arm
must be carefully cleaned and dried using soft tissues and water
Careful cleaning will solve
most contamination problems
It is also important to wipe the cabinet to avoid
possible staining of painted surfaces
Professor R. P. Clark & M. L. de Calcina-Goff
The FRAVALET Company Limited
KI-DISCUS
The End
Presented by:
Professor Raymond P. Clark OBE CEng FSEE HonFRPS &
Professor M. Leonardo de Calcina-Goff
ASIS FRPS FSEE FBPA
The FRAVALET Company Limited
INNOVATION IN HEALTH CARE DELIVERY
5 B High Street, Newport Pagnell, Buckinghamshire, MK16 8AR
Telephone: 01908 211790
Email: fravalet@medi.demon.co.uk
Professor R. P. Clark & M. L. de Calcina-Goff