Bsi bs en 00852 1 1996

/home/gencode/cen/bsen8521/en8521 1 4634 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |[.]

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

|

852-1 : 1996

BS 2782 : Part 11 : Method 1122A : 1996

The European Standard EN 852-1 : 1996 has the status of a

British Standard

ICS 23.040.20

NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW

Plastics piping systems for the

transport of water intended

for human consumption Ð

Migration assessment

Part 1 Determination of migration values

of plastics pipes

This British Standard, having

been prepared under the

direction of the Sector Board for

Materials and Chemicals, was

published under the authority of

the Standards Board and comes

into effect on

15 November 1996

 BSI 1996

The following BSI references

relate to the work on this

standard:

Committee reference PRI/61

Draft for comment 92/47152 DC

ISBN 0 580 26266 9

BS EN 852-1 : 1996

Amendments issued since publication

Amd No Date Text affected

Committees responsible for this British Standard

The preparation of this British Standard was entrusted to Technical Committee PRI/61, Plastics piping systems and components, upon which the following bodies were represented:

British Gas Plc British Plastics Federation British Plumbing Fittings Manufacturers' Association British Valve and Actuator Manufacturers' Association Chartered Institution of Water and Environmental Management Department of the Environment (British Board of AgreÂment) Department of the Environment (Building Research Establishment) Department of the Environment (Property and Buildings Directorate) Department of Transport

Electricity Association Federation of Civil Engineering Contractors Health and Safety Executive

Institute of Building Control Institute of Materials Institution of Civil Engineers Institution of Gas Engineers National Association of Plumbing, Heating and Mechanical Services Contractors Pipeline Industries Guild

Plastics Land Drainage Manufacturers' Association Society of British Gas Industries

Society of British Water Industries Water Companies Association Water Services Association of England and Wales

The following bodies were also represented in the drafting of the standard, through subcommittees and panels:

ERA Technology Ltd

Engineering Equipment and Materials Users' Association RAPRA Technology Ltd

BS EN 852-1 : 1996

Contents

Page

Method

Annexes

B (normative) Additional procedures for testing pipes with nominal size in

Figures B.1 Test arrangement 1 8

B.2 Test arrangement 2 9

B.3 Cross section pipe segment 10

BS EN 852-1 : 1996

National foreword

This British Standard has been prepared by Technical Committee PRI/61 and is the

English language version of EN 852-1 : 1996 Plastics piping systems for the transport

of water intended for human consumption Ð Migration assessment Ð Part 1: Determination of migration values of plastics pipes, published by the European

Committee for Standardization (CEN)

It is incorporated into BS 2782 Methods of testing plastics Part 11: Thermoplastics

pipes, fittings and valves, as Method 1122A : 1996, for association with related test

methods for plastics materials and plastics piping components

This test method has been prepared for reference by other standards under preparation by CEN for specification of plastics piping systems and components It has been implemented to enable experience of the method to be gained and for use for other fresh applications

It is also for use for the revision or amendment of other national standards as practicable, but it should not be presumed to apply to the purposes of BS 6920 or to any other existing standard or specification which contains or makes reference to a different test method until that standard/specification has been amended or revised to make reference to this method and adjust any requirements as appropriate

Cross-references

Publication referred to Corresponding British Standard

ISO 3696 : 1987 BS EN ISO 3696 : 1995 Water for analytical laboratory use Ð

Specification and test methods

ISO 7393-2 : 1985 BS 6068 Water quality

Part 2 Physical, chemical and biochemical methods Section 2.26 : 1986 Method for determination of free chlorine

and total chlorine : colorimetric method using N,N-diethyl-1,4-phenylenediamine, for routine control purposes

NOTE 1 There is no British Standard identical to EN 1420-1 pending the ratification thereof and its implementation as BS EN 1420-1.

NOTE 2 In equation B.3 the preferred expression for `tg (¯ a)' is `tan (¯ a)'.

NOTE 3 In B.5, to clarify the variables a and a, references should have been made in the text to figure

B.3 and a should be taken to mean the arc length on the inside surface of the pipe segment.

Also in B.5, in the second paragraph and in the two definitions of A, reference is made to a `hatched

circle segment', but no hatched area is shown on the figures in EN 852-1 : 1996 as ratified.

Pending issue of a correction, the area A should be interpreted as corresponding to the cross-sectional

area of the channel provided by the test piece G to contain the relevant liquid when arranged as shown in

figure B.1 Hence A is the area of the segment of the cross section shown in figure B.3 as bounded by the pipe internal cross section up to the height h.

This document comprises a front cover, an inside front cover, pages i and ii, pages 1

to 10, an inside back cover and a back cover

Warning note This British Standard, which is identical with EN 852-1 : 1996, does not

necessarily detail all the precautions necessary to meet the requirements of the Health and Safety at Work etc Act 1974 Attention should be paid to any appropriate safety precautions and the method should be operated only by trained personnel

Compliance with a British Standard does not of itself confer immunity from legal obligations.

European Committee for Standardization Comite EuropeÂen de Normalisation EuropaÈisches Komitee fuÈr Normung

Central Secretariat: rue de Stassart 36, B-1050 Brussels

1996 All rights of reproduction and communication in any form and by any means reserved in all countries to CEN and its members

Ref No EN 852-1 : 1996 E

ICS : 23 040 20

Descriptors: Water pipelines, potable water, plastics tubes, tests, estimation, migrations, components

English version

Plastics piping systems for the transport of water intended for

human consumption Ð Migration assessment Ð Part 1: Determination of migration values of plastics pipes

SysteÁmes de canalisations plastiques pour le

transport d'eau destineÂe aÁ la consommation

humaine Ð EÂ valuation de la migration Ð

Partie 1: DeÂtermination des valeurs de migration

des tubes plastiques

Kunstoff-Rohrleitungssysteme fuÈr den Transport von Wasser fuÈr den menschlichen Verzehr Ð Bewertung der Migration Ð

Teil 1: Bestimmung der Migrationswerte von Kunststoff Rohren

This European Standard was approved by CEN on 1996-01-27 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 Central Secretariat 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 Central Secretariat has the

same status as the official versions

CEN members are the national standards bodies of Austria, Belgium, Denmark,

Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands,

Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom

Page 2

EN 852-1 : 1996

Foreword

This European Standard has been prepared by

Technical Committee CEN/TC 155, Plastics piping

systems and ducting systems, the secretariat of which

is held by NNI, and consists of two Parts:

± Part 1: Determination of migration values of

plastics pipes;

± Part 2: Determination of the number of

migrations and conversion of laboratory values.

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

November 1996, and conflicting national standards

shall be withdrawn at the latest by November 1996

It is based on ISO 8795 : 1990 Plastics pipes for the

transport of water intended for human

consumption Ð Extractibility of constituents Ð Test

method, published by the International Organization for

Standardization (ISO) It differs from ISO 8795 : 1990

due to the need for the test method to be applicable to

European conditions and practice

The main modifications are:

a) test liquids:

± pH 11, which is not a European condition, is

deleted;

± pH 7 has been changed to pH 9, to cover

European conditions (see Directive 80/778/EEC

Appendix 1.B);

± addition of test liquid with an active chlorine

content of 1 mg/l;

b) a stagnation period has been added;

c) exposure time: 72 h is specified;

d) temperatures:

27 ÊC is deleted (tropical condition not relevant to

Europe);

70 ÊC is specified for moderate hot water

conditions;

e) large diameter pipes: a test arrangement for large

diameter pipes has been added

Annex A, which is normative, describes the preparation

of test liquids

Annex B, which is normative, describes additional procedures for testing pipes with nominal sizes in excess of 80

Annex C, which is informative, gives a bibliography When a standard on this subject covering the requirements in the referring standard is issued by CEN/TC 164, this CEN/TC 155 standard will be withdrawn

This standard is one of a series of standards on test methods which support system standards for plastics piping systems and ducting systems

According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom

Page 3

EN 852-1 : 1996

 BSI 1996

1 Scope

This standard specifies a method for the determination

of the migration of constituents from the internal

surface of plastics pipes Organoleptic and

microbiological assessments are not included

This standard is applicable to all plastics pipes to be

used for the transport of water intended for human

consumption and raw water used for the

manufacturing of water intended for human

consumption It covers all constituents which are

extractable by water from a finished pipe It provides

for a change in procedure as necessary depending

upon the size of the pipe

For each application and each material, the relevant

test conditions need to be stated in the system

standard concerned

2 Normative references

This standard 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 standard only when

incorporated in it by amendment or revision For

undated references the latest edition of the publication

referred to applies

EN 1420-1 Influence of materials on water

intended for human consumption Ð Organic materials Ð Pipes, fittings and their coatings used in piping systems Ð Odour and flavour assessment of water Ð Part 1: Test method

ISO 3696 : 1987 Water for analytical laboratory

use Ð Specification and test methods

ISO 7393-2 : 1985 Water quality Ð Determination of

free chlorine and total chlorine Ð Part 2: Colorimetric method using N,N-diethyl-1,4-phenylenediamine, for routine control purposes

3 Definitions

For the purposes of this standard the following

definitions apply:

3.1 migration

Movement of substances from one material (plastics

pipe) into another (test liquid)

3.2 test liquid

A specified water for migration testing

3.3 migration value (M)

The mass of constituent(s) migrated from a specified inner surface area of a pipe test piece exposed to a test liquid at a specified temperature over a specified time

3.4 tapwater

Water intended for human consumption

4 Principle

Test pieces are subjected to stagnation and prewashing with tapwater for a specified time The test pieces are then filled with the specified test liquid at a specified temperature and kept for a series of specified migration periods The test liquid is then analysed to assess any constituents which were able to migrate

NOTE It is assumed that the following test parameters are set by the standard making reference to this standard:

a) the test liquid(s) (see 5.2);

b) the test temperature, T, if other than as given in clause 6;

c) the number of pairs of test pieces (see 8.3);

d) the constituents for which analysis is to be made both upon test pieces and the blank test and the required accuracy, taking

account of 9.5 (see also clause 10).

5 Reagents

5.1 Water, conforming to grade 3 of ISO 3696 : 1987,

with the following characteristics:

a) a conductivity of # 10 mS/m at 25 ÊC;

b) total organic carbon (TOC) content # 0,2 mg/l (as carbon);

c) negligible concentrations of any measurable substances that could interfere with measurements

to determine a) and b)

5.2 Test liquids

NOTE Methods for the preparation of test liquids are given in annex A.

5.2.1 Water, conforming to 5.1.

5.2.2 Chlorinated water, conforming to 5.1 with an

active chlorine concentration of (1±0,2) mg/l

5.2.3 Acidic water, comprising water conforming

to 5.1, adjusted to a pH of (4,5±0,1) with a KH2PO4

buffer solution conforming to A.1.2.

5.2.4 Chlorinated acidic water, comprising water

conforming to 5.1, adjusted to a pH of (4,5±0,1) with

a KH2PO4buffer solution conforming to A.1.2 and an

active chlorine concentration of (1±0,2) mg/l

5.2.5 Alkaline water, comprising water conforming

to 5.1, adjusted to a pH of (9,0±0,1) with a boric acid

buffer solution conforming to A.1.3.

5.3 Selection of test liquids

5.3.1 For cold water applications the test liquids shall

conform to 5.2.1 to 5.2.5 inclusive.

5.3.2 For warm and hot water applications (see

clause 6) the test liquid shall conform to 5.2.1.

Page 4

EN 852-1 : 1996

6 Test temperatures

Unless otherwise specified in the referring standard,

the test temperature shall be selected as follows:

a) for cold water applications the test temperature is

(23±2) ÊC;

b) for warm water applications the test temperature

is either (60±2) ÊC or (70±2) ÊC, depending upon

the class of pipe;

c) for hot water applications the test temperature is

(90±2) ÊC.

7 Apparatus

7.1 Connections, stoppers and containers, made of

material which is inert at the specified test conditions,

such as glass or PTFE or stainless steel (see also

annex B)

NOTE The material PTFE should only be used when there is a

small contact area with the test liquid, thus not for containers.

7.2 Thermostatically controlled environment or

enclosure, capable of maintaining the relevant test

temperature(s) (see clause 6).

8 Test pieces

8.1 General

The test pieces shall have an age of at least 14 days

after manufacturing of the pipe

8.2 Preparation

For each test, take two test pieces from a pipe, each of

sufficient length and surface to give the volume of the

test liquid necessary to determine, with the required

accuracy, the amount of any migrated consituent(s)

The value of S/V shall not be less than 5 (dm21),

where:

S is the inner surface area of test piece, in

square decimetres, exposed to the test liquid;

V is the volume of test liquid, in litres;

except as follows For pipes with nominal sizes in

excess of 80, where the S/V value of 5 cannot be

conformed to, then the test arrangement shall be

adjusted to one of the methods as given in annex B

NOTE The value of S/V is dependent on the analytical

requirements for each specific constituent of interest, particularly

the minimum concentration to be determined [see d) of the note

to clause 4] The lowest value for S/V is then determinant.

8.3 Number

The number of pairs of test pieces shall be as specified

in the referring standard

9 Procedure

9.1 General 9.1.1 Carry out the procedures given in 9.2 to 9.5 in

duplicate at the same time

Complete the sequence consisting of stagnation (9.2), prewashing (9.3) and finally migration (9.4)

within 10 days (see 9.1.2).

9.1.2 Carry out a blank test in parallel with 9.1.1,

using the same test conditions (test liquid, test temperature, migration time and stoppers) in a

container of sufficient volume conforming to 7.1, but

made of glass Determine at the end of each migration

period (see 9.4) the concentration, C0, of each

specified constituent [see d) of the note to clause 4]

and associated interfering substances with the required accuracy

NOTE If a bulk supply of test liquid is used for the duplicate test then one blank test is sufficient.

9.2 Stagnation time

9.2.1 Pipes to be tested at 23 ÊC

9.2.1.1 Close one end of each test piece, using a

stopper (see 7.1).

9.2.1.2 Fill the test piece with tapwater and let it

stand for (24±0,5) h at the test temperature (see

clause 6).

9.2.1.3 After this period remove the water and

stopper Prewash the test piece in accordance with 9.3.

9.2.2 Pipes to be tested at elevated temperatures

9.2.2.1 Close one end of each test piece using a

stopper (see 7.1).

9.2.2.2 Fill the test piece with tapwater at the test

temperature (see clause 6) and let it stand for

(7,5±0,5) h at the test temperature

9.2.2.3 After this period, remove the water and refill

the test piece with fresh tapwater which has been brought to the test temperature and let it stand for (16±0,5) h at the test temperature.

9.2.2.4 After this period, remove the water and

stopper Prewash the test piece in accordance with 9.3.

9.3 Prewashing 9.3.1 Connect the test piece to a source of tapwater

via a suitable connector (see 7.1) such that the test

surface is totally covered during prewashing

9.3.2 Let the tapwater flow through the test piece

with a velocity between 2 m/min and 4 m/min

9.3.3 Maintain the water flow for a period

between 60 min and 70 min

9.3.4 Stop the water flow and rinse out the test piece

using water conforming to 5.1.

9.4 Migration test 9.4.1 Close one end of each test piece, which has

been subjected to the prewashing, using a stopper

(see 7.1).

Page 5

EN 852-1 : 1996

 BSI 1996

9.4.2 Fill the test piece with the specified test liquid

(see clause 4 and 5.2) Close the other end of each test

piece using a stopper (see 7.1) and maintain the filled

test piece at the specified temperature for (72±1) h

9.4.3 For the first migration, at the end of the first

test period remove the stopper, empty the test liquid

from the test piece into a suitable container Determine

to the specified accuracy the amount of each specified

constituent present, C1(see 9.5 and clause 10).

9.4.4 For any subsequent migration n repeat the

steps 9.4.2 and 9.4.3 to determine C n where n

corresponds to the number of times those steps have

been carried out (the migration number)

NOTE The total number of migrations should conform to the

requirements of EN 852-2.

9.5 Analysis of constituents

While maintaining the necessary precautions for the

test piece integrity, transfer the test liquid to be

analysed into a container of inert material (see 7.1)

and, if applicable, allow to cool down to (23±2) ÊC

Carry out the required analysis for extracts using

appropriate analytical methods where the extracted

substances to be determined and the limits of

detection and accuracy, i.e total tolerable random

(precision) and systematic (bias) error of the analytical

results, shall be as specified in the referring standards

10 Expression of results

The measured concentrations of the relevant

constituent(s) shall be expressed in milligrams per

litre The migration value, M, for a migrated constituent

shall be calculated using the following equation:

M24=1C723

3

V S

where:

M24 is the migration value, in milligrams per square

decimetres per 24 h;

C72 is the concentration of the migrated amount of

each constituent, in milligrams per litre over a

period of 72 h, where C72= C1{ or C n } 2 C0;

V is the volume of test liquid, in litres;

S. is the inner surface area of test piece, in

square decimetres, exposed to the test liquid

The results for M and C shall be expressed as M t;a T and

where

C t;a T

T is the migration temperature, in degrees

Celsius;

t is the migration time, in hours;

a is the sequence number of the migration

period

EXAMPLES:

M24;123 is M for the first migration at 23 ÊC for a

migration time, t, of 72 h divided by 3;

M24;370 is M for the third migration at 70 ÊC for a

migration time, t of 72 h divided by 3;

C72;123 is C for the first migration at 23 ÊC for a

migration time, t, of 72 h;

C72;370 is C for the third migration at 70 ÊC for a

migration time, t, of 72 h.

NOTE The migration value M is independent of the size of the

pipe tested and is expressed in mass per unit area per unit time While the migration time is 72 h and the unit time is 24 h the factor 1/3 is introduced in the equation For practical reasons it is assumed that the migration is linear in time From the expression

of M as M t;a T it is easy to read which migration time, in hours, and which migration temperature, in degrees Celsius, and which sequence number of the migration period was used.

11 Test report

The test report shall include the following information: a) a reference to this standard and to the referring standard;

b) a complete identification of the pipe test piece tested, including the following:

1) name of manufacturer and production site; 2) name and type of material;

3) pipe marking including production code; 4) dimensions of the sample: nominal size and nominal wall thickness;

5) description of the test piece;

c) the analytical method, its accuracy and the detection limit used for the determination of the constituent(s) concerned;

d) the volume of the test liquid, V, in litres, and the

inner surface area of the test piece exposed to the

test liquid, S, in square decimetres;

e) the test liquid, the type of buffer and the test temperature;

f) concentrationsC 72;a T and C0in milligrams per

litre (mg/1) and the calculated migration value M 24;a T

in milligrams per square decimetre, 24 h [mg/(dm2´24 h)] of each constituent determined for each of the two test pieces after the first and any subsequent migration;

g) the arithmetic mean ofC 72;a T andM 24;a T of the

duplicate test pieces (see 9.1.1) for each constituent

determined after the first and any subsequent migration;

h) any factors which may have affected the results, such as any incidents or any operating details not specified in this standard;

i) the date of test

Page 6

EN 852-1 : 1996

Annex A (normative)

Test liquids

A.1 Chemical solutions

A.1.1 Sodium hypochlorite (NaOCl) solution

A solution of sodium hypochlorite (NaOCl) in water

conforming to 5.1 with a concentration of 0,1 % by

mass available chlorine is prepared on the day of use

by dilution of a sodium hypochlorite solution

(technical grade) with water conforming to 5.1.

NOTE The sodium hypochlorite solution is not sufficiently stable

for prior preparation.

A.1.2 Acidic buffer solution (pH 4,5)

An acidic buffer solution is prepared by

dissolving 13,61 g of potassium dihydrogen phosphate

(KH2PO4) in 1000 ml of water conforming to 5.1 and

diluting this solution by 1 : 100 with water conforming

to 5.1.

1,2 ml 0,1 N HCl per litre diluted solution is then added

A.1.3 Alkaline buffer solution (pH 9,0)

An alkaline stock buffer solution is prepared by mixing

a solution A and 1000 ml of solution B as follows

Solution A shall comprise 420 ml of 0,1 N sodium

hydroxide in water conforming to 5.1.

Solution B is made by dissolving 6,18 g of boric acid

in 0,1 M potassium chloride made with water

conforming to 5.1 and diluting to (1000±1) ml with the

same (0,1 M potassium chloride) solution

This alkaline stock buffer solution is diluted 1 : 100

with water conforming to 5.1.

A.2 Preparation of test liquids

A.2.1 Water having an active chlorine

concentration

Add a sufficient quantity of a sodium

hypochlorite (NaOCl) solution conforming to A.1.1 to

water conforming to 5.1 to give an active chlorine

concentration of (1,0±0,2) mg/l Determine this

concentration according to ISO 7393-2

A.2.2 Acidic water

Add to water conforming to 5.1 enough phosphate

buffer solution conforming to A.1.2 to obtain a pH

of (4,5±0,1)

A.2.3 Acidic water with an active chlorine

concentration

Determine in accordance with ISO 7393-2 the active

chlorine concentration in the acidic water conforming

to A.2.2 Add a sufficient quantity of a sodium

hypochlorite (NaOCl) solution conforming to A.1.1 to

give an active chlorine concentration of (1,0±0,2) mg/l

A.2.4 Alkaline water

Add to water conforming to 5.1 enough alkaline buffer

solution conforming to A.1.3 to obtain a stable pH

of (9,0±0,1).

Annex B (normative) Additional procedures for testing pipes with nominal size in excess of 80

B.1 Arrangements for testing

Use the test arrangements shown in figures B.1 and B.2

Take precautions to ensure that there is no loss of test liquid during the migration periods

B.2 Flushing of the test piece

Flush the test piece in accordance with either 9.3 or,

to avoid the use of large quantities of water, the procedure given in annex B of EN 1420-1

In case of dispute, the procedure given in 9.3 shall be

used

B.3 Blank test

Carry out the blank test in accordance with 9.1.2,

ensuring that all materials that will come into contact with the test liquid will be included in the blank test

and that they are present at the same S/V ratio as in

the actual test arrangement

B.4 Sealing

Silicone will not be used for sealing

Seal the test assembly by mechanical fixing as follows Secure the end pieces against the pipe segments to provide a seal e.g by means of clamps or bolts If a seal cannot be achieved then use PTFE tape or film in the form of a gasket, with minimal surface in contact

with test liquid (see 7.1).

B.5 Calculation of the S/V value for test

arrangement 1

Calculate the S/V value for test arrangement B.1

when S and V are calculated as follows.

From the cross section of the pipe segment calculate

the arc length a and the surface area A of the hatched

circle segment using the following equations

(B.1)

a = a 3πdi

360 where:

a is the arc length, in millimetres;

di is the internal diameter of the pipe from which the segment is taken, in millimetres;

a is the sector angle, in degrees i.e

(B.2) cos (¯a) =di2 2h

di

where:

h is the height of the segment, in millimetres

(B.3)

A = a 3 ïp 2 2

360 (di)  [ (¯di2 h)23 tg(¯ a) ]