EN ISO 23500-3:2019

SLOVENSKI STANDARD
01-maj-2019
1DGRPHãþD
SIST EN ISO 13959:2016
3ULSUDYDLQYRGHQMHNDNRYRVWLWHNRþLQ]DKHPRGLDOL]RLQSRGREQHWHUDSLMHGHO
9RGD]DKHPRGLDOL]RLQSRGREQHWHUDSLMH,62
Preparation and quality management of fluids for haemodialysis and related therapies -
Part 3: Water for haemodialysis and related therapies (ISO 23500-3:2019)
Leitfaden für die Vorbereitung und das Qualitätsmanagement von Konzentraten für die
Hämodialyse und verwandte Therapien - Teil 3: Wasser für die Hämodialyse und
verwandte Therapien (ISO 23500-3:2019)
Préparation et management de la qualité des liquides d'hémodialyse et de thérapies
annexes - Partie 3: Eau pour hémodialyse et thérapies apparentées (ISO 23500-3:2019)
Ta slovenski standard je istoveten z: EN ISO 23500-3:2019
ICS:
11.120.99 Drugi standardi v zvezi s Other standards related to
farmacijo pharmaceutics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 23500-3
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2019
EUROPÄISCHE NORM
ICS 11.040.40 Supersedes EN ISO 13959:2015
English Version
Preparation and quality management of fluids for
haemodialysis and related therapies - Part 3: Water for
haemodialysis and related therapies (ISO 23500-3:2019)
Préparation et management de la qualité des liquides Leitfaden für die Vorbereitung und das
d'hémodialyse et de thérapies annexes - Partie 3: Eau Qualitätsmanagement von Konzentraten für die
pour hémodialyse et thérapies apparentées (ISO Hämodialyse und verwandte Therapien - Teil 3:
23500-3:2019) Wasser für die Hämodialyse und verwandte Therapien
(ISO 23500-3:2019)
This European Standard was approved by CEN on 14 January 2019.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 23500-3:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 23500-3:2019) has been prepared by Technical Committee ISO/TC 150
"Implants for surgery" in collaboration with Technical Committee CEN/TC 205 “Non-active medical
devices” the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2019, and conflicting national standards
shall be withdrawn at the latest by September 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 13959:2015.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 23500-3:2019 has been approved by CEN as EN ISO 23500-3:2019 without any
modification.
INTERNATIONAL ISO
STANDARD 23500-3
First edition
2019-02
Preparation and quality management
of fluids for haemodialysis and related
therapies —
Part 3:
Water for haemodialysis and related
therapies
Préparation et management de la qualité des liquides d'hémodialyse
et de thérapies annexes —
Partie 3: Eau pour hémodialyse et thérapies apparentées
Reference number
ISO 23500-3:2019(E)
©
ISO 2019
ISO 23500-3:2019(E)
© ISO 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 1
4.1 Dialysis water quality requirements . 1
4.2 Chemical contaminant requirements . 2
4.2.1 General. 2
4.2.2 Organic Carbon, pesticides and other chemicals . 3
4.3 Dialysis water microbiological requirements . 3
5 Tests for microbiological and chemical requirements . 4
5.1 Dialysis water microbiology . 4
5.2 Microbial contaminant test methods . 4
5.3 Chemical contaminants test methods . 5
Annex A (informative) Rationale for the development and provisions of this document .8
Bibliography .16
ISO 23500-3:2019(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www .iso
.org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 150, Implants for surgery, Subcommittee
SC 2, Cardiovascular implants and extracorporeal systems.
This first edition cancels and replaces ISO 13959:2014, which has been technically revised. The main
changes compared to the previous edition are as follows:
— The document forms part of a revised and renumbered series dealing with the preparation and
quality management of fluids for haemodialysis and related therapies. The series comprise
ISO 23500-1 (previously ISO 23500), ISO 23500-2, (previously ISO 26722), ISO 23500-3, (previously
ISO 13959), ISO 23500-4, (previously ISO 13958), and ISO 23500-5, (previously ISO 11663).
A list of all parts in the ISO 23500 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www. iso. org/members. html.
iv © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
Introduction
Assurance of adequate water quality is one of the most important aspects of ensuring a safe and
effective delivery of haemodialysis, haemodiafiltration, or haemofiltration.
This document contains minimum requirements, chemical and microbiological, for the water to be used
for preparation of dialysis fluids, concentrates, and for the reprocessing of haemodialysers and the
necessary steps to ensure conformity with those requirements.
Haemodialysis and related therapies such as haemodiafiltration can expose the patient to more than
500 l of water per week across the semi-permeable membrane of the haemodialyser or haemodiafilter.
Healthy individuals seldom have a weekly oral intake above 12 l. This over 40-fold increase in exposure
requires control and regular surveillance of water quality to avoid excesses of known or suspected
harmful substances. Since knowledge of potential injury from trace elements and contaminants of
microbiological origin over long periods is still growing and techniques for treating drinking water are
continuously developed, this document will evolve and be refined accordingly. The physiological effects
attributable to the presence of organic contaminants in dialysis water are important areas for research,
however, the effect of such contaminants on patients receiving regular dialysis treatment is largely
unknown, consequently no threshold values for organic contaminants permitted in water used for the
preparation of dialysis fluids, concentrates, and reprocessing of haemodialysers has been specified in
this revised document.
Within this document, measurement techniques current at the time of publication have been cited.
Other standard methods can be used, provided that such methods have been appropriately validated
and are comparable to the cited methods.
The final dialysis fluid is produced from concentrates or salts manufactured, packaged, and labelled
according to ISO 23500-4 mixed with water meeting the requirements of this document. Operation of
water treatment equipment and haemodialysis systems, including on-going surveillance of the quality
of water used to prepare dialysis fluids, and handling of concentrates and salts are the responsibility
of the haemodialysis facility and are addressed in ISO 23500-1. Haemodialysis professionals make
choices about the various applications (haemodialysis, haemodiafiltration, haemofiltration) and should
understand the risks of each and the requirements for safety for fluids used for each.
This document is directed towards manufacturers and providers of water treatment systems and also
to haemodialysis facilities.
The rationale for the development of this document is given in informative Annex A.
INTERNATIONAL STANDARD ISO 23500-3:2019(E)
Preparation and quality management of fluids for
haemodialysis and related therapies —
Part 3:
Water for haemodialysis and related therapies
1 Scope
This document specifies minimum requirements for water to be used in haemodialysis and related
therapies.
This document includes water to be used in the preparation of concentrates, dialysis fluids for
haemodialysis, haemodiafiltration and haemofiltration, and for the reprocessing of haemodialysers.
This document excludes the operation of water treatment equipment and the final mixing of treated
water with concentrates to produce dialysis fluid. Those operations are the sole responsibility of
dialysis professionals. This document does not apply to dialysis fluid regenerating systems.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 23500-1, Preparation and quality management of fluids for haemodialysis and related therapies —
Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 23500-1 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
4 Requirements
4.1 Dialysis water quality requirements
The quality of the dialysis water, as specified in 4.2 and 4.3, shall be verified upon installation of a water
treatment system. Regular surveillance of the dialysis water quality shall be carried out thereafter.
NOTE Throughout this document it is assumed that the water undergoing treatment is potable water and
therefore meets the appropriate regulatory requirements for such water. If the water supply is derived from
an alternate source such as a privately-owned borehole or well, contaminant levels cannot be as rigorously
controlled.
ISO 23500-3:2019(E)
4.2 Chemical contaminant requirements
4.2.1 General
Dialysis water shall not contain chemicals at concentrations in excess of those listed in Tables 1 and
2, or as required by national legislation or regulations. Table 1 does not include any recommendation
in respect of organic carbon, pesticides and other chemicals such as pharmaceutical products and
endocrine disruptors that can be present in feed water. It is technically difficult and costly to measure
such substances on a routine basis. The effect of their presence on haemodialysis patients is difficult
to define and consequences of exposure are probably of a long-term nature. Furthermore, there is an
absence of evidence of their widespread presence in water although it is recognized that inadvertent
discharges are possible. In view of this, it is not at present possible to define limits for their presence in
water used in the preparation of dialysis fluid.
Nanofiltration and reverse osmosis are capable of significant rejection of many such compounds.
Granular Activated Carbon (GAC) is also highly effective at removing majority of these chemicals.
However, as Granular Activated Carbon is widely used in the removal chlorine/chloramine, their use in
the removal or organic carbons, pesticides and other chemicals will be dependent upon the size of the
carbon filters and/or beds and users shall be aware of appropriate dimensioning since the majority of
carbon valences can be already occupied and not available for further removal activity.
NOTE 1 See A.3 for an explanation of values supplied.
NOTE 2 The maximum allowable levels of contaminants listed in Tables 1 and 2 include the anticipated
uncertainty associated with the analytical methodologies listed in Table 4.
Where the dialysis water is used for the reprocessing of haemodialysers (cleaning, testing, and mixing
of disinfectants), the user is cautioned that the dialysis water shall meet the requirements of this
document. The dialysis water should be measured at the input to the dialyser reprocessing equipment.
Table 1 — Maximum allowable levels of toxic chemicals and dialysis fluid electrolytes in
a
dialysis water
Maximum concentration
Contaminant
b
mg
Contaminants with documented toxicity in haemodialysis
Aluminium 0,01
Total chlorine 0,1
Copper 0,1
Fluoride 0,2
Lead 0,005
Nitrate (as N) 2
Sulfate 100
Zinc 0,1
a
A physician in charge of dialysis has ultimate responsibility for ensuring the quality of
water used for dialysis.
b
Unless otherwise indicated.
When chlorine is added to water, some of the chlorine reacts with organic materials and
metals in the water and is not available for disinfection (the chlorine demand of the water).
The remaining chlorine is the total chlorine, and is the sum of free or non bound chlorine and
combined chlorine.
There is no direct method for the measurement of chloramine. It is generally established by
measuring total and free chlorine concentrations and calculating the difference. When total
chlorine tests are used as a single analysis the maximum level for both chlorine and chloramine
shall not exceed 0,1 mg/l. Since there is no distinction between chlorine and chloramine, this
safely assumes that all chlorine present is chloramine.
2 © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
Table 1 (continued)
Maximum concentration
Contaminant
b
mg
Electrolytes normally included in dialysis fluid
Calcium 2 (0,05 mmol/l)
Magnesium 4 (0,15 mmol/l)
Potassium 8 (0,2 mmol/l)
Sodium 70 (3,0 mmol/l)
a
A physician in charge of dialysis has ultimate responsibility for ensuring the quality of
water used for dialysis.
b
Unless otherwise indicated.
When chlorine is added to water, some of the chlorine reacts with organic materials and
metals in the water and is not available for disinfection (the chlorine demand of the water).
The remaining chlorine is the total chlorine, and is the sum of free or non bound chlorine and
combined chlorine.
There is no direct method for the measurement of chloramine. It is generally established by
measuring total and free chlorine concentrations and calculating the difference. When total
chlorine tests are used as a single analysis the maximum level for both chlorine and chloramine
shall not exceed 0,1 mg/l. Since there is no distinction between chlorine and chloramine, this
safely assumes that all chlorine present is chloramine.
Table 2 — Maximum allowable levels of other trace elements in dialysis water
Maximum concentration
Contaminant
mg/l
Antimony 0,006
Arsenic 0,005
Barium 0,1
Beryllium 0,000 4
Cadmium 0,001
Chromium 0,014
Mercury 0,000 2
Selenium 0,09
Silver 0,005
Thallium 0,002
4.2.2 Organic Carbon, pesticides and other chemicals
The presence of organic compounds, such as pesticides, polycyclic aromatic hydrocarbons and other
chemicals such as pharmaceutical products and endocrine disruptors in respect of haemodialysis
patients are difficult to define. Consequences of exposure are probably of a long-term nature and it is
technically difficult and costly to measure these substances on a routine basis. Furthermore, there is
an absence of evidence of their widespread presence in water although it is recognized that inadvertent
discharges are possible. In view of this, it is at present not possible to define limits for their presence in
water used in the preparation of dialysis fluid.
4.3 Dialysis water microbiological requirements
Total viable microbial counts in dialysis water shall be less than 100 CFU/ml, or lower if required by
national legislation or regulations. An action level shall be set based on knowledge of the microbial
dynamics of the system. Typically, the action level will be 50 % of the maximum allowable level.
Endotoxin content in dialysis water shall be less than 0,25 EU/ml, or lower if required by national
legislation or regulations. An action level shall be set, typically at 50 % of the maximum allowable level.
ISO 23500-3:2019(E)
Fungi (yeasts and filamentous fungi) can coexist with bacteria and endotoxin in the dialysis water.
Further studies on the presence of fungi in haemodialysis water systems, their role in biofilm formation
and their clinical significance are required and in view of this, no recommendation in respect of
permitted maximum limits is made.
NOTE See A.4 for a history of these requirements.
5 Tests for microbiological and chemical requirements
5.1 Dialysis water microbiology
Samples shall be collected where a dialysis machine connects to the water distribution loop, and from a
sample point in the distal segment of the loop or where such water enters a mixing tank.
Samples should be analysed as soon as possible after collection to avoid unpredictable changes in the
microbial population. If samples cannot be analysed within 4 h of collection, they should be stored
at <10 °C without freezing until ready to transport to the laboratory for analysis. Sample storage for
more than 24 h should be avoided, and sample shipping should be in accordance with the laboratory’s
instructions.
Total viable counts (standard plate counts) shall be obtained using conventional microbiological assay
procedures (pour plate, spread plate, membrane filter techniques). Membrane filtration is the preferred
method for this test. Other methods may be used, provided that such methods have been appropriately
validated and are comparable to the cited methods. The use of the calibrated loop technique is not
acceptable.
5.2 Microbial contaminant test methods
Methodology to establish microbial contaminant levels is given in Table 3. Such methods provide only a
relative indication of the bacterial bioburden rather than an absolute measure.
Recommended methods and cultivation conditions can also be found in ISO 23500-4 and ISO 23500-5 as
well as this document (Table 3). The methodology detailed uses Tryptone Glucose Extract Agar (TGEA)
and Reasoner’s Agar No. 2 (R2A) incubated at 17 °C to 23 °C for a period of 7 days and Tryptic Soy Agar
[8]
(TSA) at an incubation temperature of 35 °C to 37 °C and an incubation time of 48 h . The background
for the inclusion of TSA for standard water and standard dialysis fluid used for standard dialysis is
explained in detail in A.4.
Different media types and incubation periods can result in varying colony concentrations and types of
[8][9][10]
microorganisms recovered . The use of Reasoner’s 2A agar (R2A) has been shown in previous
studies to result in higher colony counts than tryptic soy agar (TSA) for water and dialysis fluids
[10][11][12]
samples . In a more recent publication, in 2016, the authors indicated that there were no
significant differences for comparisons of bacterial burden of standard dialysis water and standard
dialysis fluid yielding colony counts ≥50 CFU/ml when assayed using R2A and TSA at the conditions
[8]
stated in the preceding paragraph of this subclause .
Historic studies with tryptone glucose extract agar (TGEA) incubated at 17 °C to 23 °C for a period
[13] [8]
of 7 days also yielded higher colony counts than TSA. Maltais et al. in their comparison of this
medium with TSA showed that the proportion of standard dialysis water samples yielding colony
counts ≥50 CFU/ml was significantly different from that found using TSA at an incubation temperature
of 35 °C to 37 °C and an incubation time of 48 hours (p = 0,001). The proportions of dialysis fluid
samples in which microbial burden was ≥50 CFU/ml were not significantly different on the two media
and incubation conditions.
The culture medium and incubation times selected should be based on the type of fluid to be analysed
e.g. standard dialysis fluid, water used in the preparation of standard dialysis fluid, ultrapure dialysis
fluid, water used for the preparation of ultrapure dialysis fluid or fluid used for online therapies
such as haemodiafiltration. The method selected, should be based on the analysis of the advantages,
disadvantages and sensitivity, of each of the methods detailed above. According to the United States
4 © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
Pharmacopeia, “the decision to use longer incubation times", should be made after balancing the need
for timely information and the type of corrective actions required when alert or action level is exceeded
with the ability to recover the microorganisms of interest. The advantages gained by incubating
for longer times namely recovery of injured microorganisms, slow growers, or more fastidious
microorganisms, should be balanced against the need to have a timely investigation and take corrective
action, as well as the ability of these microorganisms to detrimentally affect products or processes”
[e.g. patient safety].
Other methods may be used, provided that such methods have been appropriately validated and are
comparable to the cited methods. Blood agar and chocolate agar shall not be used.
Currently there are no requirements for routine surveillance for the presence of fungi (i.e. yeasts
and filamentous fungi) which can coexist with other microbial species, however if indication of their
presence is required, membrane filtration is the preferred method for the provision of a sample
suitable for analysis. Culture media used should be Sabouraud, or Malt Extract Agar (MEA) media.
Other methods may be used, provided that such methods have been appropriately validated and are
comparable to the cited methods. An incubation temperature of 17 °C to 23 °C and an incubation time
of 168 h (7 d) are recommended. Other incubation times and temperatures can be used, provided it has
been demonstrated that such methods have been appropriately validated and are comparable to the
cited methods.
The presence of endotoxins shall be determined by a Limulus amoebocyte lysate (LAL) assay or other
validated method.
Table 3 — Culture techniques
Incubation
Culture medium Incubation time
temperature
Tryptone Glucose Extract Agar (TGEA) 17 °C to 23 °C 7 d
Reasoner's Agar no. 2 (R2A) 17 °C to 23 °C 7 d
a
Sabouraud or Malt Extract Agar 17 °C to 23 °C 7 d
b
Tryptic Soy Agar (TSA) 35 °C to 37 °C 48 h
a
Intended for the quantification of yeasts and filamentous fungi. Currently there are no requirements in
this document for their routine surveillance; they have been included for completeness.
b
The use of TSA has been only validated for measurement of standard dialysis water.
5.3 Chemical contaminants test methods
Conformity with the requirements listed in Table 1 can be shown by using chemical analysis methods
[1][2][3] [4]
referenced by the ISO , the American Public Health Association or the US Environmental
[5][6]
Protection Agency methods referenced in applicable pharmacopoeia, or by any other equivalent
validated analytical method.
Conformity to the requirements listed in Table 2 can be shown in one of the three ways below.
— Where such testing is available, the individual contaminants in Table 2 can be determined using
[1][2][3] [4]
chemical analysis methods referenced by ISO , the American Public Health Association or
[5][6]
the US Environmental Protection Agency , or other equivalent analytical methods.
— Where testing for the individual trace elements listed in Table 2 is not available, and the source
water can be demonstrated to meet the standards for potable water as defined by the WHO or local
[7]
regulations , an analysis for total heavy metals can be used with a maximum allowable level of
0,1 mg/l.
— If neither of these options is available, conformity with the requirements of Table 2 can be met
by using water that can be demonstrated to meet the potable water requirements of the WHO or
local regulations and a reverse osmosis system with a rejection of > 90 % based on conductivity,
ISO 23500-3:2019(E)
resistivity, or TDS. Samples shall be collected at the end of the water purification cascade or at the
most distal point in each water distribution loop.
Table 4 lists for information suitable test methods for each contaminant, along with an appropriate
reference.
Table 4 — Analytical test methods for chemical contaminants
Contaminant Analytical technique Reference, method number
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Aluminium
Atomic absorption (electrothermal)
American Public Health Assn, #3113
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Antimony
Atomic absorption (platform)
US EPA, #200.9
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Arsenic
Atomic absorption (gaseous hydride)
American Public Health Assn, #3114
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Barium
Atomic absorption (electrothermal)
American Public Health Assn, #3113
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Beryllium
Atomic absorption (platform)
US EPA, #200.9
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Cadmium
Atomic absorption (electrothermal)
American Public Health Assn, #3113
Inductively coupled plasma mass spectrometry or
ISO 17294–2:2016
EDTA (Ethylene diamine tetraacetic acid) titrimet-
Calcium ric method or
American Public Health Assn, #3500-Ca D
atomic absorption (direct aspiration) or
American Public Health Assn, #3111B
ion specific electrode
DPD(N-Diethyl-p-Phenylenediamine) ferrous titri-
metric method or
DPD (N-Diethyl-p-Phenylenediamine)colourimetric American Public Health Assn, #4500-Cl F
Total chlorine
method American Public Health Assn, #4500-Cl G
Thio-Michler’s Ketone (TMK/MTK) colourimetric
method
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Chromium
Atomic absorption (electrothermal)
American Public Health Assn, #3113
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Copper Atomic absorption (direct aspiration) or
American Public Health Assn, #3111
neocuproine method
American Public Health Assn, #3500-Cu D
Ion chromatography or ISO 10304–1:2007
Ion selective electrode method or
ISO 10359–1:1992
Fluoride sodium 2-(parasulfophenylazo)-1,8-dihydroxy-
-
3,6-naphthalenedisulfonate American Public Health Assn, #4500-F C
-
(SPADNS) method American Public Health Assn, #4500-F D
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry
Lead
Atomic absorption (electrothermal)
American Public Health Assn, #3113
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Magnesium Atomic absorption (direct aspiration) American Public Health Assn, #3111
Ion chromatography
EPA 300.7:1986
Flameless cold vapour technique
Mercury American Public Health Assn, #3112
(atomic absorption)
6 © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
Table 4 (continued)
Contaminant Analytical technique Reference, method number
ISO 10304–1:2007
Ion chromatography or
Spectrophotometric method using sulfosalicylic ISO 7890–3:1988
Nitrate
acid
American Public Health Assn, #4500-NO3
or Cadmium reduction method
E
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
American Public Health Assn, #3111
Atomic absorption (direct aspiration) or
Potassium
flame photometric method or
American Public Health Assn, #3500-K D
ion specific electrode
American Public Health Assn, #3500-K E
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Selenium Atomic absorption (gaseous hydride) or
American Public Health Assn, #3114
atomic absorption (electrothermal)
American Public Health Assn, #3113
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Silver
Atomic absorption (electrothermal)
American Public Health Assn, #3113
Inductively coupled plasma mass spectrometry or
ISO 17294–2:2016
Atomic absorption (direct aspiration) or
Sodium
American Public Health Assn, #3111
flame photometric method or
American Public Health Assn, #3500-Na D
ion specific electrode
ISO 10304–1:2007
Ion chromatography or
Sulfate
American Public Health Assn, #4500-
Turbidimetric method
2-
SO E
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Thallium
Atomic absorption (platform)
US EPA, 200.9
Total heavy European Pharmacopoeia, 2.4.8
Colourimetric
metals US Pharmacopoeia, < 231 >
ISO 17294–2:2016
Inductively coupled plasma mass spectrometry or
Zinc Atomic absorption (direct aspiration) or American Public Health Assn, #3111
dithizone method
American Public Health Assn, #3500-Zn D
ISO 23500-3:2019(E)
Annex A
(informative)
Rationale for the development and provisions of this document
A.1 General
Water treated in accordance with the requirements of this standard is predominantly used for the
preparation of dialysis fluid but can also be used for other applications such as the reprocessing
of haemodialysers intended for multiple use. When dialysis water is mixed with concentrated
electrolyte solutions manufactured in accordance with ISO 23500-4:2019, the requirements detailed in
ISO 23500-5:2019 apply.
A.2 Feed water
Water used in the preparation of dialysis fluid usually originates as potable water from a municipal
water supply, although in some instances the water can be from a local borehole or well. Potable water
complies with the WHO Guidelines for drinking water, or its local equivalent. These requirements define
the permitted water contaminants and their levels. As dialysis patients are exposed to larger volumes
of water than the general population, the water needs to undergo additional treatment to reduce any
risk from water contaminants and to meet the appropriate requirements detailed in 4.2 and 4.3 of this
document.
If the feed water to the water treatment infrastructure is via an indirect feed, e.g. a hospital water
system, disinfectants and antimicrobial agents can be added to supress the development of legionella
within the water system. Commonly used agents include hydrogen peroxide and silver stabilized
hydrogen peroxide. Unintended exposure to both have resulted in adverse events in dialysis patients
as remaining residues cannot be removed by reverse osmosis and rely on the use of activated carbon.
If drinking water has chlorine and /or chloramine added to minimize bacterial content, both of these
compounds are toxic to dialysis patients and are removed by the water treatment system as outlined in
ISO 23500-2; Guidance for the preparation and quality management of fluids for haemodialysis and related
therapies — Part 2: Water treatment equipment for haemodialysis applications and related therapies.
Removal of those compounds renders the water susceptible to bacterial proliferation and biofouling
unless appropriate preventative measures are taken as outlined in ISO 23500-1 Guidance for the
preparation and quality management of fluids for haemodialysis and related therapies — Part 1: General
requirements.
While the majority of bacteria in the feed water are faecal in origin, and the measures that the water
utility takes are intended to minimize their proliferation, the feed water can also contain other microbial
compounds such as cyanotoxins that occur in the presence of cyanobacteria or blue green algae.
Cyanotoxins are considered natural contaminants that occur worldwide. Specific classes of cyanotoxins
have shown regional prevalence. The Americas encompassing North Central and South America often
show high concentrations of microcystin, anatoxin-a, and cylindrospermopsin in freshwater, whereas
those in Australia often show high concentrations of microcystin, cylindrospermopsin, and saxitoxins.
Other less frequently reported cyanotoxins include lyngbyatoxin A, debromoaplysiatoxin, and beta-
[14]
N-methylamino-L-alanine . Cyanobacterial blooms usually occur according to a combination of
environmental factors e.g. nutrient concentration, water temperature, light intensity, salinity, water
movement, stagnation and residence time, as well as several other variables. Cyanotoxins are primarily
produced intracellularly during the exponential growth phase. Release of toxins into water can occur
during cell death or senescence but can also be due to evolutionary-derived or environmentally-
[15]
mediated circumstances such as allelopathy or relatively sudden nutrient limitation .
8 © ISO 2019 – All rights reserved

ISO 23500-3:2019(E)
In many countries, cyanotoxins have been viewed primarily as a recreational water issue. However,
there is a growing awareness of the public health risk they pose in drinking water and thus the need to
monitor and remove cyanotoxins in the drinking water treatment process. The WHO has established
a suggested drinking water guideline value of 1 μg/l and a recreational exposure guideline value of
10 μg/l for microcystin-LR. Health Canada has also published a drinking water standard of 1,5 μg/l for
microcystin-LR. While in the United States the EPA has developed health advisory recommendations
for concentrations of cyanotoxins in drinking water, namely that for adults, the recommended levels for
drinking water are at or below 1,6 μg/l for microcystins and 3,0 μg/l for cylindrospermopsin.
Currently water utilities do not regularly look for cyanobacterial toxins in the water supply unless
cyanobacteria are present in the source water. Once cyanobacteria are detected in the water supply,
treatment can remove them using a variety of different methods, such as clarification or membrane
filtration, adsorption on activated carbon or reverse osmosis, and chemical oxidation by ozonation or
chlorination.
A.3 Chemical contaminants in dialysis water
A.3.1 General
Chemical contaminants present in potable water, can pose a risk to the patient receiving dialysis
treatment. Contaminants identified as needing restrictions on their allowable level compared with
potable water have been divided into three groups for the purposes of this document; 1) chemicals
known to cause toxicity in dialysis patients; 2) physiological substances that can adversely affect the
patient if present in the dialysis fluid in excessive amounts and 3) trace elements.
A.3.2 Chemicals known to cause toxicity in dialysis patients
Chemicals known to cause toxicity to dialysis patients include those which are added to drinking
water for public health benefits. Fluoride can be present naturally in potable water or be added in low
concentrations to minimize dental caries. The maximum limit for this compound in drinking water is
set at 1,5 mg/l. The toxicity of fluoride in dialysis patients at the levels present in fluoridated water, is
questionable. In the absence of a consensus on fluoride's role in uraemic bone disease, it was initially
[16]
thought prudent to restrict the fluoride level of dialysis fluid . Isolated cases of acute exposure of
dialysis patients to elevated levels of fluoride has been described in the scientific literature. Illness in
a group of eight dialysis patients, with the death of one patient, was reported as a result of accidental
[16]
over fluoridation of a municipal water supply . Fluoride levels of up to 50 mg/l were found in water
used for dialysis that was treated only with a water softener. In another case, where deionizers were
allowed to exhaust, 12 of 15 patients became acutely ill from fluoride intoxication. Three of the patients
died from ventricular fibrillation. Fluoride concentrations in the water used to prepare the dialysis
[17]
fluid were as high as 22,5 mg/l .
Aluminium is toxic to hemodialysis patients. Salts of aluminium, such as alum, are added to drinking
water in order to facilitate chemical precipitation and flocculation of colloidal particles (turbidity). In
[18][19]
hemodialysis patients, exposure to aluminium can result in severe neurologic symptoms .
The maximum aluminium level set for dialysis water has been specified to prevent accumulation of this
[20][21]
toxic metal in the patient . Despite this, occasional sporadic outbreaks of aluminium intoxication
have been repor
...