SIST ENV 852:2002

SLOVENSKI STANDARD
SIST ENV 852:2002
01-junij-2002
Cevni sistemi iz polimernih materialov za transport pitne vode - Vrednotenje
migracije - Navodilo za razlago laboratorijsko pridobljenih migracijskih vrednosti
Plastics piping systems for the transport of water intended for human consumption -
Migration assessment - Guidance on the interpretation of laboratory derived migration
values
Kunststoff-Rohrleitungssysteme für den Transport von Wasser für den menschlichen
Verzehr - Bewertung der Migration - Anleitung für die Beurteilung von aus
Laborversuchen abgeleiteten Migrationswerten
Systemes de canalisations plastiques pour le transport d'eau destinée a la
consommation humaine - Evaluation de la migration - Guide d'interprétation des valeurs
de migration déterminées en laboratoire
Ta slovenski standard je istoveten z: ENV 852:2001
ICS:
13.060.20 Pitna voda Drinking water
23.040.20 Cevi iz polimernih materialov Plastics pipes
SIST ENV 852:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ENV 852:2002

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SIST ENV 852:2002
EUROPEAN PRESTANDARD
ENV 852
PRÉNORME EUROPÉENNE
EUROPÄISCHE VORNORM
August 2001
ICS 67.250; 83.140.30
English version
Plastics piping systems for the transport of water intended for
human consumption - Migration assessment - Guidance on the
interpretation of laboratory derived migration values
Kunststoff-Rohrleitungssysteme für den Transport von
Wasser für den menschlichen Verzehr - Bewertung der
Migration - Anleitung für die Beurteilung von aus
Laborversuchen abgeleiteten Megrationswerten
This European Prestandard (ENV) was approved by CEN on 22 July 2001 as a prospective standard for provisional application.
The period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the ENV can be converted into a European Standard.
CEN members are required to announce the existence of this ENV in the same way as for an EN and to make the ENV available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final
decision about the possible conversion of the ENV into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. ENV 852:2001 E
worldwide for CEN national Members.

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SIST ENV 852:2002
ENV 852:2001 (E)
Contents
page
Foreword 3
................................................................................................................................................
Introduction 4
............................................................................................................................................
1 Scope 5
...........................................................................................................................................
2 Normative references 5
..................................................................................................................
3 Definitions and symbols 5
.............................................................................................................
3.1 Definitions 5
......................................................................................................................................
3.2 Symbols 7
.........................................................................................................................................
4 Principle 7
.......................................................................................................................................
5 Field use 7
.......................................................................................................................................
5.1 General 7
..........................................................................................................................................
5.2 Factors 7
...........................................................................................................................................
5.3 Determination of the conversion factor, F, for pipes, fittings and joints 8
.........................................
6 Number of migration periods and assessment procedure 8
.....................................................
6.1 Number of migrations 8
....................................................................................................................
6.2 Assessment procedure 9
..................................................................................................................
7 Calculation of the field concentration, C and the acceptance migration limit, M 10
.......
f;n al
7.1 Calculation of the field concentration, C 10
..................................................................................
f;n
7.2 Calculation of the acceptance migration limit, M 10
......................................................................
al
8 Assessment report 10
....................................................................................................................
Annex A (normative) Alternative schedules for successive migration periods 11
............................
Annex B (informative) Determination of the operational factor 12
.......................................................
Annex C (informative) Example of the determination of the conversion factor, F, for pipes,
fittings and joints 15
.................................................................................................................................
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SIST ENV 852:2002
ENV 852:2001 (E)
Foreword
This European Prestandard has been prepared by Technical Committee CEN/TC 155 "Plastics piping
systems and ducting systems", the secretariat of which is held by NEN
ENV 852 includes the following annexes:
Annex A, which is normative, describes alternative schedules for the migration periods.
Annex B, which is informative, describes approaches for the determination of the operational factor.
Annex C, which is informative, describes an example of the determination of a conversion factor, F,
for pipes, fittings and joints.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this European Prestandard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
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SIST ENV 852:2002
ENV 852:2001 (E)
Introduction
This document was prepared initially by CEN/TC 155/WG 2 as a standard to complement EN 852-1
(which later became EN ISO 8795). Because of various developments relating to the regulatory
content, it is not now the intention to issue it as a standard. However, it is proposed to produce it as an
ENV. The main objective of this is to make the information available as quickly as possible to
interested groups, particularly those involved in designing the regulatory framework of harmonised
standards, such as the European Acceptance Scheme (EAS ).
EN ISO 8795 provides instructions on how to produce a migration liquid and how to calculate a
migration value (M) after analysis of a migrating substance. However, EN ISO 8795 does not give
information on :
1) number of successive migration periods to be carried out;
2) how to interpret M values calculated from successive migration periods;
3) a method for converting the calculated M values into values that reflect field use
conditions;
4) acceptance criteria for the duplicate M values obtained by testing in accordance with
EN ISO 8795.
This information is included in this document (ENV 852). In the case of the conversion of M values
(point 3), two factors have been considered:
a) a geometrical factor F , which is a property of the product;
g
b) an operational factor F , which is calculated from the residence time of the water in contact
o
with the product. The values of F quoted in this document are based on certain assumptions and/or
o
risk analysis. These are explained in the document.
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SIST ENV 852:2002
ENV 852:2001 (E)
1  Scope
This Prestandard is applicable to plastics pipes, joints and fittings to be used for the transport of water
intended for human consumption and raw water used for the manufacture of water intended for human
consumption.
It gives guidance on:
1) number of successive migration periods to be carried out;
2) how to interpret M values calculated from successive migration periods;
3) a method for converting M values into values that reflect field use conditions;
4) acceptance criteria for the duplicate M values obtained by testing in accordance with
EN ISO 8795.
2  Normative references
This European Prestandard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Prestandard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
EN ISO 8795 Plastics piping systems for the transport of water intended for human consumption —
Migration assessment — Determination of migration values of plastics pipes and fittings and their
joints (ISO 8795:2001)
3  Terms, definitions and symbols
For the purposes of this European Prestandard the following terms, definitions and symbols apply.
3.1  Terms and definitions
3.1.1 Terms and definitions related to acceptance limits
3.1.1.1
C
concentration acceptance limit ( )
al
concentration of a constituent which shall not be exceeded
It is expressed in milligrams per litre (mg/l).
NOTE The limit is specified elsewhere, e.g. in national regulations.
3.1.1.2
migration acceptance limit (M )
al
migration value for a constituent, which shall not be exceeded
2
It is expressed in milligrams per square decimetres per 24 h [mg/(dm 24 h)].
NOTE The value is either specified elsewhere e.g. in national regulations or calculated from a concentration acceptance
limit C (see 3.1.1.1) and a conversion factor F (see 3.1.3.1)
al
3.1.2  Terms and definitions related to categorisation of pipe lines
3.1.2.1
domestic pipe line
pipe line between the service pipe line (see 3.1.2.2) and the tap. It is assumed to have a nominal size
in the range 12 to 25 inclusive
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SIST ENV 852:2002
ENV 852:2001 (E)
3.1.2.2
service pipe line
pipe line between the distribution pipe line (see 3.1.2.3) and the domestic pipe line (see 3.1.2.1). It is
assumed to have a nominal size in the range 32 and 90 inclusive
3.1.2.3
distribution pipe line
pipe line between a trunk main (see 3.1.2.4) and several service pipe lines (see 3.1.2.2). It is assumed
to have a nominal size in the range 100 to 280 inclusive
3.1.2.4
trunk main
pipe line which transports water from the water works to the distribution pipe line (see 3.1.2.3). It is
assumed to have a nominal size of 300 and larger
3.1.3  Terms and definitions related to conversion factors
3.1.3.1
conversion factor (F)
—
T
factor used to convert an experimentally derived migration value M (see 3.2) to C
f;n
24;n
(see 3.1.3.2)
It is expressed in days and decimetres to power minus one (day/dm).
3.1.3.2
field concentration (C )
f;n
calculated concentration of a particular constituent under assumed conditions of field use for migration
period n
It is expressed in milligrams per litre (mg/l).
3.1.3.3
geometrical factor (F )
g
relationship between the surface area of a component of a pipe line in contact with the water and the
volume of the water contained by that component (see 5.2.1)
1It is expressed in decimetres to the power minus one (dm ).
3.1.3.4
operational factor (F )
o
time the water is assumed to be in contact with the component in practice (see 5.2.3)
It is expressed in days.
3.1.4  Terms and definitions related to products
3.1.4.1
fitting
component, other than a pipe which is used in a pipe line (e.g. bends, tees, end caps, valves)
3.1.4.2
joint
connection between the ends of two components, which includes the method of sealing
3.1.4.3
nominal size (DN)
numerical designation of the size of the pipe, fitting or joint, which is whole number approximately equal
to the actual dimensions in millimetres (mm) as specified in the relevant System Standard
3.1.5
water
water intended for human consumption or raw water used for the manufacture of water intended for
human consumption
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SIST ENV 852:2002
ENV 852:2001 (E)
3.2  Symbols
n : The sequence number of the migration period (see clause 5);
T
M : Migration value M at the temperature T in degrees Celsius, for the migration time 24 h and
24;n
 the migration period n. It is expressed in milligrams per square decimetres per  24 h
2
[mg/(dm 24 h)];
—
T T
M : The arithmetic mean value of the results of the duplicate test pieces M .
24;n
24;n
4  Principle
A maximum of ten migrations is specified.
For assessment purposes the first three and the last three migrations are used.
A procedure for the interpretation of successive migrations is provided.
Procedures are given for the conversion of laboratory derived migration values to values based on
assumed conditions of field use. These values can be compared with either a concentration
acceptance limit or with a migration acceptance limit.
5  Field use
5.1  General
The concentration C shall be calculated using equation (1):
f;n
T
C F  M 24;n (1)
f, n
where:
C is the calculated concentration of a particular constituent under assumed conditions of
f;n
field use in milligrams per litre for migration period n;
F is the conversion factor in decimetres power minus one and days;
—
T
T
M is the arithmetic mean M values in milligrams per square decimetre per 24 h (day),
24;n
24;n
obtained by application of the relevant test methods and the assessment in accordance
with 6.2.2.
5.2  Factors
5.2.1 Conversion factor
The conversion factor F shall be calculated using equation (2):
F Fg  Fo (2)
where:
F is the conversion factor (see 3.1.3.1);
F is the geometrical factor (see 3.1.3.3);
g
F is the operational factor (see 3.1.3.
...