AS/NZS 4187:2014 Steam Implications By Graeme Harley & Henry - - PowerPoint PPT Presentation

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Present by Wayne Harvey State Manager QLD & PNG National Healthcare and Pharma Sector Manager

AS/NZS 4187:2014 Steam Implications

By Graeme Harley & Henry Biggelaar

While Spirax Sarco Australia has attempted to make the information in this presentation as accurate as possible, the information in this presentation is for personal and/or educational use only and is provided in good faith without any express or implied warranty. There is no guarantee given that the information provided applies to any specific plant, process or organisation. Spirax Sarco Pty Limited does not accept responsibility for any loss or damage occasioned by use of the information. Readers should at all times seek independent and specific advice on their steam systems. Use of the information contained in this presentation is at the risk of the reader.

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1. Review the Australia Standards and Changes 2. Requirements to satisify the standards 3. Steam Quality 4. Steam Purity 5. Steam Quality versus Purity

Objectives

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• Australian Commission on Safety and Quality in Healthcare
• Standard 3 – Preventing and Controlling Healthcare Associated Infections

Standards Requirements

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Prior to 2014, the Australian Standards were:

• AS/NZS 4187:2003 Cleaning, disinfecting and sterilizing reusable medical and surgical

instruments and equipment, and maintenance of associated environments in health care facilities

• AS 1410:2003 Sterilizers – Steam - Pre-vacuum

Australian Standards

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• AS/NZS 4187:2003 referred to AS 1410:2003, which had methodology and limits for

steam quality testing in line with EN 285

• However AS/NZS 4187:2003 also included limits for the values placed on dryness

value and superheat that differ from those in AS 1410:2003, and so EN 285

• AS/NZS 4187:2003 and AS 1410:2003 had limited detail on steam purity, with

AS 1410:2003 giving recommendations on feedwater for steam generators only

Australian Standards

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• AS/NZS 4187 was revised with the current standard being AS/NZS 4187:2014
• AS/NZS 4187:2014 no longer refers to AS/NZS 1410, and instead references the

following standards:

• EN 285 Sterilization – Steam Sterilizers – Large Sterilizers
• ISO 17665 Sterilization of health care products – Moist heat –

Part 1: Requirements for the development, validation and routine control

• f a sterilization process for medical devices

Part 2: Guidance on the application of ISO 17665-1

• CFPP 01-01 Part C*

[Choice Framework for local Policies and Procedures 01-01 – Management and decontamination of surgical instruments (medical devices) used in acute care, Part C: Steam sterilization] *CFPP 01-01 Part C has been replaced by HTM 01-01 Part C

Australian Standards

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• The requirements of this Standard

are applicable to all HSO’s

• The standard does not reiterate all
• f the technical requirements

already defined in National or International Standards. For Example the standard refers directly to EN 285 and ISO 17665

• New validation requirements for

Washer Disinfectors

• Increased focus on steam purity

and clean steam

Standards and Requirements for HSO’s

AS/NZS 4187:2014 Key Points

AS/NZS 4187:2014 ISO 17665-2

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Washer Disinfectors validated to ISO 15883 Steam sterilization validated to ISO 17665 – Part 1

Standards and Requirements for HSO’s

AS/NZS 4187:2014 Key Points Validation

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Steam Quality Steam quality tests, e.g. steam dryness value, super heat and non-condensable gases tests shall be conducted as part of IQ or OQ and in accordance with EN 285

• Minimum steam dryness value is 0.95

(AS/NZS 4187:2003 required 0.97)

• Superheat limit of 25°C above atmospheric conditions for the expanded steam

(AS/NZS 4187:2003 required less than 2°C superheat in the steam supply)

• The volume of non-condensable gases should not exceed 3.5% of the volume
• f condensed steam

AS/NZS 4187:2014 is now fully aligned with EN 285 and ISO 17665

Standards and Requirements for HSO’s

AS/NZS 4187:2014 Key Points Steam

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Steam Purity The focus on steam purity and the move to clean steam is a major update in AS/NZS 4187:2014, which now has the following requirements:

• Water supplied to the steam generator is in accordance with EN 285 Table B.1
• Steam purity tests shall be conducted as part of IQ or OQ and in accordance with the

requirements of EN 285 (see also Table 10.1) and the results shall not exceed the limits specified in EN 285 Table E.2

Standards and Requirements for HSO’s

AS/NZS 4187:2014 Key Points Steam

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However, EN 285 was revised in 2015 and:

• Table E.2 was removed
• Table 4 was added

Table 4 is almost identical to Table A.1 in ISO 17665-2, which deals with contaminants with regard to corrosion, so is looking at clean steam EN 285:2015 requires:

“steam that does not contain contaminants in quantities that can impair the sterilization process or harm or contaminate the sterilizer or sterilized load”

Standards and Requirements for HSO’s

AS/NZS 4187:2014 Key Points Steam

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Testing Steam Quality and Purity

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The three tests done to determine steam quality are: 1. Dryness Value Testing 2. Non-Condensable Gas (NCG) Testing 3. Superheat Testing Steam Quality Testing is fairly well entrenched and there is little change here, apart from dryness value and super heat test limits aligning with EN 285 and ISO 17665

Steam Quality Tests

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Steam Quality Test Points

The test points for the steam should be as close to the sterilizer as possible, but before the final separator and pressure reduction into the sterilizer.

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Three test points are required in the steam supply to the sterilizer.

Steam Quality - Test Points Detail

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Steam purity and clean steam is a more recent inclusion in the standard, so there is a need to understand the requirements. AS/NZS 4187:2014 refers to EN 285, and also ISO 17665 – EN 285 contains methodology for sampling steam condensate – EN 285:2006+A2:2009 had two tables regarding limits on steam contaminants;

• Table E.2 - Contaminates in condensate from steam used by the sterilizer to be considered in relation to

contamination of the load

• Table B.2 - Contaminants in condensate from steam supply to the sterilizer measured at the sterilizer inlet

– EN 285:2015 has a single table regarding limits on steam contaminants;

• Table 4 - Suggested maximum values of contaminants in condensate from steam supply to the sterilizer

chamber

– Unlike Table E.2, Table 4 does not refer to Bacterial Endotoxins (Pyrogens), so can be considered with regard to corrosion of materials (the requirement for clean steam)

Steam Purity Testing

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– ISO 17665-2:2009 has two tables regarding limits on steam contaminants;

• Table A.1 - Contaminates in condensate measured at the steam inlet to the sterilizer to be considered in

relationship to the corrosion of materials

• Table A.2 - Contaminants in condensate from steam used by the sterilizer to be considered in relation to

contamination of the load

– ISO 17665-2:2009 Table A.1 and A.2 are the same as table B.2 and E.2 (respectively) in EN 285:2006+A2:2009 – EN 285:2015 Table 4 is identical to ISO 17665-2:2009 Table A.1, except Table A.1 has a lower conductivity limit (<= 3 μS/cm at 25°C table A.1 compared to <= 4.3 μS/cm at 20°C Table 4)

Steam Purity Testing

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– EN 285:2006+A2:2009 and EN 285:2015 both also contain a table on feedwater contaminants;

• Table B.1 - Contaminants in feed water supplied to a dedicated steam generator

– These tables are identical in both revisions of EN 285, except that there is a lower level

• f Chloride allowable in EN 285:2015

Steam Purity Testing

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– This should be regarded as the minimum steam purity requirement and includes testing for Bacterial Endotoxins (Pyrogens) – AS/NZS 4187:2014 references Table E.2 of EN285:2006+A2:2009, which is the same as Table A.2 in ISO 17665-2:2009 – Table E.2 has been removed from EN285:2015, so to keep in line with the intent of AS/NZS 4187:2014 testing for contamination with regard to Load should be done to Table A.2 of ISO 17665-2:2009 – Table 10.1 of AS/NZS 4187:2014 indicates annual testing

Steam Purity Testing Contamination with regard to Load

ISO 17665-2:2009

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– For a clean steam generator the steam purity still needs to meet the requirements of contamination with regard to Load, and in addition should also meet the requirements of contamination with regard to Corrosion – Testing for contamination with regard to Corrosion should be done to Table A.1 of ISO 17665-2:2009 (which is almost identical to Table 4 in EN 285:2015)

Steam Purity Testing Contamination with regard to Corrosion

(Conductivity limit of EN285 Table 4 is 4.3 μS/cm at 20°C) ISO 17665-2:2009

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– For a clean steam generator the Feedwater should also be tested (as per Table 10.1 of AS/NZS 4187:2014) – Feedwater for a dedicated generator should be tested to Table B.1 of EN 285:2015

Feedwater Purity Testing

EN 285:2015

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EN 285:2015 EN 285:2006+A2:2009 ISO 17665-2:2009

Table B.1 - Contaminants in feed water supplied to a dedicated steam generator Table B.1 - Contaminants in feed water supplied to a dedicated steam generator Table 4 - Suggested maximum values of contaminants in condensate from steam supply to the sterilizer chamber Table B.2 - Contaminants in condensate from steam supply to the sterilizer measured at the sterilizer inlet Table A.1 - Contaminates in condensate measured at the steam inlet to the sterilizer to be considered in relationship to the corrosion of materials Table E.2 - Contaminates in condensate from steam used by the sterilizer to be considered in relation to contamination of the load Table A.2 - Contaminants in condensate from steam used by the sterilizer to be considered in relation to contamination

• f the load

Steam Purity Tables - Summary

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While the need for steam quality has a long established history, steam purity and the move to clean steam is a more recent evolution of the standards. A clean steam generator must produce steam that meets both the Quality and Purity requirements, and must be able to be tested and measured for IQ or OQ. The desire to make generators small and compact can compromise the steam quality, causing problems with the sterilizer. When problems occur, counter measures, such as reducing load size or extending drying times may be used, but these do not address the potential issue of poor steam quality.

Steam Quality versus Purity

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The dryness test was initially developed for conditions where there is a separator and pressure reduction (typically 2:1) installed on the sterilizer steam inlet. These have a drying effect, and as they are after the test point will increase the dryness value of the steam actually entering the sterilizer. Clean steam generators may operate at lower pressures with little or no pressure reduction, so the loss of the drying effect could mean a higher steam dryness value may actually be needed to avoid wet loads.

Steam Quality versus Purity

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Present by Wayne Harvey State Manager QLD & PNG National Healthcare and Pharma Sector Manager

AS/NZS 4187:2014 Steam Implications

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