STERILISATION RANGE

Synergy Health (UK) Ltd, Healthcare Solutions 1 Western Ave, Matrix Park, Chorley, Lancashire, PR7 7NB, UKTel: +44(0)1772 299900, Fax: +44(0)1772 299901 Email: healthcaresolutions@synergyhealthplc.comwww.synergyhealthplc.com

Azowrap is a registered trademark of Synergy Health Limited. © Synergy Health Limited 2017SHI6350 Rev00

FOR A PACKAGING SYSTEM TO BE EFFICIENT, IT MUST BE

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PorousTo allow efficient passage of the sterilisation media

BarrierEffective against bacteria to prevent recontamination

StrongTo maintain integrity of the packaging

SYNERGY HEALTH BRINGS YOU

The delivery of sterile surgical instruments to the operating theatre not only depends on the quality of the sterilisation process, but also upon the efficacy of the packaging material used.

The AZOWRAP sterilisation single use range includes crepe, non-woven and SMS fabrics in single sheet, interleaved and bonded formats. This wide range enables you to tailor the complete Packaging System to the instrument container, ensuring efficient sterilisation and anti-microbial protection throughout the life cycle of the instrument tray.

POROUS

During the sterilisation of surgical instruments, the packaging system must allow the rapid entry and exit of the sterilisation medium into the interior of the pack in order to ensure that the contents are fully sterilised.

BARRIER

Whilst allowing the penetration and extraction of the sterilisation medium, the sterile barrier system must prevent the ingress of microorganisms and unwanted foreign bodies to the pack interior, in order to maintain sterility of the contents.

AIR PERMEANCE – THE BENDTSEN POROSITY TEST – ISO 5636-3

This test determines the volume of air that can flow through a 10 cm2 section of test material in 1 minute, using a pressure gradient of 1.47 kPa.

AIR COMPRESSOR

THROUGH AIR FLOW CONTROL

PAPER SAMPLE

REGULATED PRESSURE 1.47 kPa

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WATERBORNE PARTICLES

DUSTVIRUS

FUNGI

NO BACTERIA

AIRBORNE PARTICLES

MICROORGANISMS

NO MICROORGANISMS

MAXIMUM PORE SIZE TEST – EN 868-2 Annex E

This test uses increasing pressure to force air through the pores of the test material. The pressure required to generate the first air bubble, is correlated with a pore size using data provided in the EN 868 standard.

The maximum pore size should not exceed 50µm (individual value), and the average of 10 values should be ≥ to 35μm. INCREASING AIR

PRESSURE

FIRST AIR BUBBLE

WETTING LIQUID LAYER

TEST MATERIAL

PAPER SAMPLE

HIGH POROSITY TEST – EN ISO 20811

This test measures the volume of air that can flow through a section of test material per minute using a pressure gradient of 12.7mm of water.

Unlike the test for crepe paper, the result is expressed as litre/min/100cm2.

AIR FLOW METER

AIR

MATERIAL

MANOMETER

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The flow properties of the AZOWRAP range are dependent on the pores found within the wrap material. If the pores are too large, microorganisms can penetrate too easily. Too small and the sterilisation medium with have difficulty both penetrating and evacuating the pack.

Sterilisation wrap porosity must adhere to the requirements found within standard EN 868-2.

Below are some of the test methods employed to ensure that the AZOWRAP range meets those requirements.

The AZOWRAP range achieves this via the ‘tortuous path’ principle.

The fibres of the wrap material combine during the manufacturing process, to form a complex network of channels and pores, creating a ‘tortuous path’ and preventing easy access to the interior of the pack.

Microorganisms can be carried by both air and liquids, therefore it is essential that the capability of the bacterial barrier is tested in both the wet and dry states.

Evaluation of the AZOWRAP range is performed using three main tests:

- Dry DIN test

- Wet DIN test

- Bacterial Filtration Efficiency (BFE) Test

TEST PERFORMED ON AZOWRAP™ NON-WOVEN STERILISATION WRAPS

TESTS PERFORMED ON AZOWRAP™ CREPE STERILISATION WRAPS

BIG PORE DIAMETER

Maintenance of Sterile State

LOW

Maintenance of Sterile State

HIGH

SMALL PORE DIAMETER

SAME MEAN POROSITY

Cellulose Wet Laid Non-woven SMS Non-woven

WET AND DRY DIN TESTS

Test samples of wrap material are placed on top of agar, inside a petri dish. A sample of microorganism, in either wet of dry form, is then placed on top of the wrap material. Any microorganisms passing through the wrap to the agar below results in a test ‘fail’.

AGAR MEDIUM

SAMPLE

BACTERIA

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BFESingle Wrapping

layer

BFEDouble Wrapping

Layer

AZOWRAP Crepe 96% to 99% 99.9%

AZOWRAP Non-woven 90% 98%

AZOWRAP SMS 93% 99%

New Linen 48% 75%

Re-used Linen 17% 59%

BACTERIAL SUSPENSION

PETRI DISH WITH MEDIUM

ANDERSEN SAMPLER

PAPER

CONDENSOR

PUMP

AEROSOL CHAMBER

HIGH PRESSURE AIR SOURCE

BFE TEST – ASTM F2101

The bacterial filtration efficiency test uses aerosolised staphylococcus aureus to challenge the filtration capabilities of the test material. The aerosol is passed over the sample of test material using high pressure air. Any microorganisms passing through the test sample, are collected in petri dishes below, cultured and then counted providing a measure of BFE.

The higher the % BFE, the better the filtration capability of the sterilisation wrap.

Comparison of BFE values for single use and reusable wrapping

In addition to the testing using microorganisms, the AZOWRAP range undergoes a range of testing designed to further determine its barrier capabilities to water at elevated pressures.

THE MASON JAR METHOD – EN 868-2 Annex E

The Mason jar method is a test of bacterial barrier performance under wet conditions, specifically for non-woven materials

The results of the test are expressed in minutes, and are defined as the time taken for the first drop of saline solution to penetrate the test piece

Although the latest revision of EN 868 does not specify a minimum requirement, the previous revision did specify a minimum limit of >75 minutes.

This limit is applied to all AZOWRAP non-woven materials.

SALINE SOLUTION

510ML

Pressure due to water weight

TIME FOR 1 DROP TO BE OBSERVED

MATERIAL TESTED

HYDROSTATIC TEST – EN 20811

The hydrostatic test determines the height of water (in cm) required to force 3 water droplets through the test piece of material. This dynamic pressure test exposes the wrap material to ever increasing water pressure, until the point that leakage occurs.

The higher the column of water required, the more resistive the material is.

The hydrostatic test, described in EN 20811, is required for non-woven wrap material only, to comply with part 2 of the EN 868 standard. The standard does not stipulate a minimum requirement.

Typical Values for the AZOWRAP range

HYDROSTATIC HEAD TESTER

WATER PRESSURE

WATER COLUMN

(CM)

TEST FABRIC

Units MethodAZOWRAP Non-woven

57gsm

AZOWRAP Non-woven

66gsm

AZOWRAP SMS 43gsm

AZOWRAP SMS 55gsm

Mason Jar mins EDANA 170-1-02 110 140 110 300

Hydrostatic test mbar ISO 811 30 29 54 56

The requirements of the ‘packaging system’ are defined in ISO 11607: PART 1

– The sterile barrier system is the minimum package that prevents ingress of microorganisms and allows aseptic presentation of the product at the point of use

– Protective packaging is the configuration of materials, designed to prevent the sterile barrier system and its contents from damage, from time of assembly to the point of use

Because each instrument tray is unique, there is no singular global solution for meeting the ‘Packaging system’ requirements of ISO 11607. CSSD’s must validate their storage, transport, and handling solutions individually through risk assessment.

The AZOWRAP range has undergone testing designed to provide data, that will assist CSSD’s in making these risk assessments

STRONG

The maintenance of pack integrity is as dependent on the ability of the wrap to resist tearing or puncture, as it is on the ability to prevent the ingress of microorganisms. Any tear, hole or burst would provide an ingress point for microorganisms, and compromise the sterility of the contents. Therefore, the packaging system must combine a sterile barrier system with protective packaging properties.

PACKAGING SYSTEM

Serile Barrier System

Protective Packaging

TENSILE STRENGTH AT BREAK – EN ISO 1924-2

The force required to break a standardised sample of test material in tension. The test can be performed either wet or dry, to simulate the conditions found within the autoclave.

Tensile strength is measured in kN/m.

STRETCH AT BREAK – EN ISO 1924-2

Measured during the Tensile Strength at Break test, the result is indicated as the % increase of the length of the standardised sample prior to testing.

Minimum requirements for both tests are defined within EN 868-2 for both crepe and non-woven materials.

CLAMP

CLAMP

TRACTION

AZOWRAP SAMPLE

PREVENTING WET PACKS

A common issue encountered during the sterilisation process is that of wet packs or ‘moisture phenomenon’. The cause can be due to various factors;

Possible causes

Whatever the cause, the consequence is always the same, reprocessing of the tray. This is because the presence of residual water either inside or outside the pack presents a high risk of sterility failure for the following reasons:

– Presence of water implies an incorrect sterilisation process

– Presence of water provides a potential ingress route for microorganisms

How can wet packs be prevented?

If all the alternative causes have been investigated and eliminated, then there are products within the AZOWRAP range that may provide a solution.

To prevent and minimize the occurrence of wet packs it is recommended that AZOWRAP tray liners are used at the base of the baskets.

In conjunction with the AZOWRAP tray liners, it is also recommended that cellulosic fibre based wraps (AZOWRAP Crepe or AZOWRAP Non-woven) are used. Cellulosic fibres have superior absorbency properties when compared with SMS based wraps, and can absorb a greater quantity of residual moisture from inside the tray. This moisture is more easily dispersed during the drying cycle, compared with water pooled within the instrument tray.

INITIATED TEAR RESISTANCE – EN 21974

This test measures the force in milliNewtons (mN) required to tear a standardised sample of wrap material, a key property for avoiding unwanted perforation by the tray corners and during tray transportation. 

DIAPHRAGM

ANNULAR CLAMP

ANNULAR CLAMP

AZOWRAP SAMPLE

AIR PRESSURE

BURST TEST – EN ISO 2758 (DRY) – EN ISO 3689 (WET)

A vital test used to determine a materials ability to withstand the repeated pressurisation and depressurisation experienced during the steam sterilisation process. A circular sample of wrap is subjected to increasing air pressure until failure, with the result being given in kPa (kiloPascals).

The test can be performed in either wet or dry conditions to simulate the conditions within the autoclave.

EN 868-2 defines minimum requirements for non-woven materials in both wet and dry conditions.

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10%

30%60%

Improper wrapping and loading

Steriliser performance

Steam supply

External wetness Internal wetness

– Poor water or steam quality

– Residue from the cleaning process

– Incorrect positioning in the autoclave (densely packed together)

– Overloading the autoclave

– Incorrect/Overloading of instruments in the tray

– Tray wrapped without absorbent materials

– Superheated steam

– Faulty autoclave cycle

To determine the protective capabilities of wrapping materials, it is important to perform tests:

– Before and after sterilisation

– In the wet state, and the dry state

RESISTANCE TESTS

CLEAN SHEETS

In the CSSD, a good sterilisation process begins with clean tray wrap. Reducing the bioburden (the number of viable microorganisms in or on a medical device before sterilisation) decreases the number of microorganisms the sterilisation media must destroy, increasing the probability of a successful sterilisation cycle.

Reducing the bioburden of the tray wrap prior to sterilisation, gives added confidence that the sterilisation process will be able to deliver a sterile end product. The AZOWRAP sterilisation range is manufactured and packaged to ensure that a bioburden of 100CFU/100cm2 is never exceeded.

This limit is based on European and US pharmacopoeia (EP & USP) microbial quality limits for non-sterile dosage forms and raw materials:

Total Aerobic Microbial Count (CFU/g or CFU/ml) = 103

Total Combined Yeasts and Molds (CFU/g or CFU/ml) 102

All AZOWRAP products are tested in accordance with ISO 11737 for aerobic bacteria, yeasts and molds.

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STERILISATION

STERILISATION

Uncontrolled Bioburden > 100 CFU / 100cm2

Controlled Bioburden < 100 CFU / 100cm2

Risk that some microorganisms are left

No microorganisms left NEED TO DO CUTTER FOR FLAP