EN 12497:2005

• Abstract:

  This European Standard is one in a series of Standards for the determination of heavy metals in an aqueous extract of paper and paperboard intended for contact with food. This European Standard specifies the test method for the determination of mercury in an aqueous extract.; It is applicable to paper and board with extractable mercury content exceeding 0,06 mg per kg.; NOTE 1 The above limit of determination is 5 times below than the actual limit existing today or proposed in Europe.; NOTE 2 Mercury content levels below 0,06 mg per kg can be measured by this European Standard if very sensitive equipment is available and if all other laboratory conditions fulfil the requirements for trace element analysis.

• Status: Published
• Publication Date: 23-Aug-2005
• Withdrawal Date: 27-Feb-2006
• ICS: 67.250 - Materials and articles in contact with foodstuffs
• ICS: 85.060 - Paper and board
• Technical Committee: CEN/TC 172 - Pulp, paper and board
• Drafting Committee: CEN/TC 172/WG 3 - Analytical methods for the assessment of paper and board in contact with foodstuffs
• Current Stage: 9060 - Closure of 2 Year Review Enquiry - Review Enquiry
• Start Date: 02-Sep-2026
• Completion Date: 02-Sep-2026
• Ref Project: SIST EN 12497:2005 - Paper and board - Paper and board intended to come into contact with foodstuffs - Determination of mercury in an aqueous extract

• Replaces: ENV 12497:1998 - Paper and board - Paper and board intended to come into contact with foodstuffs - Determination of mercury in an aqueous extract
• Effective Date: 22-Dec-2008
• Refers: EN 647:1993 - Paper and board intended to come into contact with foodstuffs - Preparation of a hot water extract
• Effective Date: 28-Jan-2026
• Refers: EN 645:1993 - Paper and board intended to come into contact with foodstuffs - Preparation of a cold water extract
• Effective Date: 28-Jan-2026
• Referred By: CLC/TS 62046:2005 - Safety of machinery - Application of protective equipment to detect the presence of persons
• Effective Date: 09-Feb-2026
• Referred By: CLC/TS 62046:2008 - Safety of machinery - Application of protective equipment to detect the presence of persons
• Effective Date: 09-Feb-2026
• Referred By: EN ISO 8230-1:2008 - Safety requirements for dry-cleaning machines - Part 1: Common safety requirements (ISO 8230-1:2008)
• Effective Date: 28-Jan-2026
• Referred By: EN ISO 10218-2:2011 - Robots and robotic devices - Safety requirements for industrial robots - Part 2: Robot systems and integration (ISO 10218-2:2011)
• Effective Date: 28-Jan-2026

Overview

EN 12497:2005 - published by CEN - specifies a chemical-analytical method for the determination of mercury in an aqueous extract of paper and board intended to come into contact with foodstuffs. The method targets extractable mercury and is applicable where extractable mercury exceeds 0,06 mg/kg. The procedure combines standardized extract preparation (cold or hot water extract) with cold vapour generation atomic absorption spectrometry (CV-AAS) for mercury quantification.

Key topics and technical requirements

• Scope and applicability
  • Applies to paper and board food-contact materials; designed for extractable mercury > 0,06 mg/kg.
  • Measurement below 0,06 mg/kg is possible only with very sensitive equipment and trace-element lab conditions.
• Sample preparation
  • Prepare extracts according to EN 645 (cold water) or EN 647 (hot water).
  • Stabilize extracts by adding nitric acid (3.5 ml per 100 ml extract). Analyze promptly (extract concentration can fall within two weeks).
• Chemical treatment
  • Oxidize organic mercury forms with potassium dichromate (≈10 mg K2Cr2O7 per 100 ml extract).
  • Inactivate excess oxidant with hydroxylammonium chloride before reduction.
• Measurement principle
  • Use atomic absorption spectrometer with cold vapour generation.
  • Reduce Hg(II) to elemental mercury using either tin(II) chloride or sodium tetrahydroborate, as recommended by instrument manufacturer.
• Quality control and calibration
  • Prepare daily reference solutions from a mercury stock (1000 mg/l) and run blanks.
  • Use standard additions when matrix effects prevent straightforward measurement.
  • Determine detection limit from blanks (LOD = 3 × std. dev. of blanks; limit of determination = 3 × LOD).
• Trace analysis precautions
  • Use reagents and water suitable for trace element analysis; acid-wash glassware and avoid contamination.
• Results expression
  • Report mercury as mg/kg or mg/dm² of paper; include blank-corrected values and test-report metadata.

Applications and users

• Who uses EN 12497:2005
  • Accredited testing laboratories performing food-contact material compliance testing.
  • Quality-control teams in paper, board and packaging manufacturing.
  • Regulatory bodies and conformity assessors verifying heavy metal limits in food-contact substrates.
• Practical uses
  • Routine QC screening for extractable mercury in packaging papers.
  • Investigations of contamination incidents or supplier qualification.
  • Supporting regulatory compliance and product safety declarations.

Related standards

• EN 645 - Preparation of a cold water extract (normative reference)
• EN 647 - Preparation of a hot water extract (normative reference)
• EN 12497:2005 supersedes ENV 12497:1998

Keywords: EN 12497:2005, mercury determination, paper and board, food contact materials, aqueous extract, cold vapour AAS, trace element analysis, heavy metals, CEN.

SLOVENSKI STANDARD
01-december-2005
1DGRPHãþD
SIST ENV 12497:2000
3DSLUNDUWRQLQOHSHQND±3DSLUNDUWRQLQOHSHQNDYQHSRVUHGQHPVWLNX]åLYLOL±
'RORþHYDQMHåLYHJDVUHEUDYYRGQHPHNVWUDNWX
Paper and board - Paper and board intended to come into contact with foodstuffs -
Determination of mercury in an aqueous extract
Papier und Pappe - Papier und Pappe für den Kontakt mit Lebensmitteln - Bestimmung
von Quecksilber in einem wässrigen Extrakt
Papier et carton - Papiers et cartons destinés a entrer en contact avec les denrées
alimentaires - Détermination du mercure dans un extrait aqueux
Ta slovenski standard je istoveten z: EN 12497:2005
ICS:
67.250 Materiali in predmeti v stiku z Materials and articles in
živili contact with foodstuffs
85.060 Papir, karton in lepenka Paper and board
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 12497
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2005
ICS 67.250; 85.060 Supersedes ENV 12497:1998
English Version
Paper and board - Paper and board intended to come into
contact with foodstuffs - Determination of mercury in an aqueous
extract
Papier et carton - Papiers et cartons destinés à entrer en Papier und Pappe - Papier und Pappe für den Kontakt mit
contact avec les denrées alimentaires - Détermination du Lebensmitteln - Bestimmung von Quecksilber in einem
mercure dans un extrait aqueux wässrigen Extrakt
This European Standard was approved by CEN on 27 June 2005.
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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, 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
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 12497:2005: E
worldwide for CEN national Members.

Contents page
Foreword .3
1 Scope.4
2 Normative references.4
3 Principle.4
4 Reagents.4
4.1 General.4
4.2 Nitric acid (HNO3), 65 % (d = 1,42).4
4.2.1 Nitric acid (4.2), diluted 1 : 1 (V/V) with water .4
4.2.2 Nitric acid (4.2), diluted to 1,5 % (V/V) with water.4
4.3 Potassium permanganate (KMnO ), 5 % aqueous solution (m/V) .4
4.4 Mercury, stock solution, 1000 mg/l.4
Sulphuric acid (H SO ), (d = 1,84).5
2 4
4.6 Potassium dichromate (K Cr O ), 50 g/l in sulphuric acid solution .5
2 2 7
4.7 Hydroxylammonium chloride (HONH Cl), 20 g/l aqueous solution.5
4.8 Reducing solutions.5
4.8.1 Tin (II) chloride (SnCl ⋅⋅⋅⋅ 2H O), 50 g/l in 10 % hydroxhloric acid (4.9.1) .5
2 2
4.8.2 Sodium tetrahydroborate (NaBH ), 0,2 g/l in 0,05 % sodium hydroxide solution (4.10) .5
4.9 Hydrochloric acid (HCl), 36 % (d = 1,19).5

4.9.1 Hydrochloric acid (4.9) (HCl), diluted 10 % (V/V) .5
4.10 Sodium hydroxide (NaOH), 0,05 % aqueous solution (m/V) .5
5 Apparatus.5
5.1 General.5
5.2 General laboratory equipment .5
5.3 Volumetric flasks, 100 ml .5
5.4 Analytical balance, accuracy 0,1 mg .5
5.5 Pipettes from 100 µl to 10 ml, glass or plastics, (high density polyethylene/polypropylene).5
5.6 Atomic absorption spectrometer with an appropriate detection system and sensitivity.6
6 Preparation of sample.6
7 Procedure.6
7.1 General.6
7.2 Preparation of reference solution.6
7.3 Determination of mercury.6
7.3.1 General.6
7.3.2 Standard additions.7
7.4 Determination of blank value .7
8 Expression of results.7

9 Precision.8
10 Test report.8

Foreword
This European Standard (EN 12497:2005) has been prepared by Technical Committee CEN/TC 172 “Pulp,
paper and board”, 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 February 2006, and conflicting national standards shall be withdrawn
at the latest by February 2006.
This European Standard supersedes ENV 12497:1998. With regard to ENV 12497:1998 the following
changes have been made:
a) implementation in a European Standard;
b) addition of the clause "Precision";
c) editorial updating.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
1 Scope
This European Standard is one in a series of standards for the
...