Water Quality Requirements of AS/NZS 4187:2014 -...

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Water Quality Requirements of AS/NZS 4187:2014

Presenter Robin Burgess

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• Why Water Treatment

• Some Common Problems

• AS/NZS 4187:2014

• Purification Methods

• The Ring MainProduct Water Distribution Loop

• Summary

Table of contents

Why Water Treatment / Poor Quality Water Instruments

• Compromised sterilisation requires higher levels of Maintenance

• Shortens the life of instruments replacement costs

• Repairs and replacements can be costly >10% of Inventory Cost Annually

Equipment

• Premature ageing of reprocessing equipment

• Shortened life of reprocessing equipment

Compliance – Patient Safety

• AS/NZS 4187:2014

• ISO 15883

• EN 285

• GENCA

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Elevated hardness:

Water with residual hardness may cause white/grey staining described in the literature as “water spots”. Residual carbonate hardness may also cause a shift of pH when water is being heated and so contributes to the corrosion.

Elevated / High Chloride:

Chloride is the number one reason for pitting and stress corrosion. The effect depends on a number of factors such as concentration; contact time; temperature and resistance of the instrument material.

Elevated / High Silicate:

Silicate causes grey or coloured staining on instruments. To achieve completely stain free instruments, for example some instrument manufacturers recommend a maximum of 0.4mg/l. The effect increases dramatically in process steps where the water is allowed to dry on the instruments.

pH-Value:

An elevated or low pH-value may cause oxidation of the surface. The effect will depend on temperature, contact time and neutralization. Typical causes are carry over of chemistry and/or water impurities.

Elevated Conductivity:

Conductivity is an indicator for the sum of all free ions. Conductivity above the standard indicated impurities, but it is not always possible to determine the exact origin.

Why Water Treatment

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• Some Common Problems

Sodium

Na+

Chloride

Cl-

Carbonate

CO32-

Potassium

K+ Aluminum

Al3+

Iron

Fe2+

Copper

Cu2+

Zinc

Zn2+ Phosphate

PO43-

Sulfate

SO42-

Nitrate

NO3-

Fluoride

F-

Hydroxide

OH-

Bicarbonate

HCO3-

Water

H2OCalcium

Ca2+

Magnesium

Mg2+

Silicate

SiO2

Major cause of instrument damage:

• Sulfate, Nitrate and Phosphate can cause

―Oxidation

―Corrosion

• Chlorides

―Major cause of pitting (rust spots)

Corrosive Anions• Some Common Problems

Biofilm , Bacteria , Spores

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• Silicates (minerals with silicon)

• Found in locations where the tap water is taken from sandy locations

• Tend to deposit on instruments causing opaque (at the beginning), or dark blue when layers growing thicker

• In steam cause a typical “snake skin” pattern

Silicate

• Some Common Problems

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• .

• Some Common Problems

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• Some Common Problems

• Hard Water Elements

Sodium

Na+

Chloride

Cl-

Carbonate

CO32-

Potassium

K+ Aluminum

Al3+

Iron

Fe2+

Copper

Cu2+

Zinc

Zn2+ Phosphate

PO43-

Sulfate

SO42-

Nitrate

NO3-

Fluoride

F-

Hydroxide

OH-

Bicarbonate

HCO3-

Water

H2OCalcium

Ca2+

Magnesium

Mg2+

Silicate

SiO2

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Scale Build-up in Washer Disinfectors

Over exposure to Acid / Silicate

• Some Common Problems / Hard Water Elements

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Can be result from old and or damaged piping , inproper Material in RO Supply

Metal Ions• Some Common Problems / Metal Ions

Poor Quality Supply in Lines / Building Works

Plating from other less noble metal instrument

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Final Rinse Water – Washer Disinfectors (as per Section 7.2.3.1, AS/NZS 4187:2014)

100

AS/NZ4187:2014

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.Steam Generator Feedwater and Stream Quality – Steam Sterilizers (Table B.1 and Table B.2)

AS/NZ4187:2014

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• AS/NZS 4187:2014 Water Quality Testing

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• Purification Methods

Water Type Characteristic

Potable Drinking water that normally contains both ionic & organic impurities

Softened Removal of calcium & magnesium

Deionized Removal of ionic impurities, but not all organic contaminates

Reverse Osmosis Removal of nearly all ionic & organic impurities

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Deionized Water

Tap Water

Control

• Purification Methods

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• Purification Methods

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Installations in the past

• Purification Methods

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Installations now and in the future

• Purification Methods

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• Purification Methods

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Purification to Distribution Loop

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One of the most important parts of the pure water system is the design of the ring main. We need to ensure that the system is built to ensure the consistent quality of water required.

Some key considerations:

• Turbulence flow by pump to retard the biofilm development• Velocity Maintenance in Return Line• Tank Turn Over – Volume Produced• Monitoring & Data logging of the process parameters• No Dead Legs

The Ring MainProduct Water Distribution Loop

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The Ring Main and Distribution Loop

Example product water capacity:

Six 86-Series Washer-Disinfectors and Five GSS67H Sterilizer Redundancy / Failure ?

If unit produced 500Ltr Hr 300Ltr Storage

240Ltr

100 Ltr

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Getinge Australia recommend the following materials to be used for RO ring mains:

• Georg Fischer Infrared welded Polypropylene Homopolymer [PPH-IR] piping

• Georg Fischer Type 519 Diaphragm Valves

• Georg Fischer PROGREF check valves

• ESP Sanitary Sampling Ports/Valves

• PNN Series Hydrophilic Nylon 0.2 Micron Membrane Filters (for advanced bacterial and endotoxin removal within circulating ring main product water).

• Big Blue carbon and particle filter set on feed water line (depending on water quality)

The Ring Main Product Water Distribution Loop

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• Summary Water

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• Summary

•Water for cleaning maybe of lesser quality only if

contaminant levels are not significant.

•If water quality is poor, then purifying method(s) should

be implemented.

•Water used for the final rinse of instruments and steam

sterilization should be of best quality e.g. RO

•For the longevity/integrity of your instruments and

equipment know your water/ steam quality and test it

regularly.