SIST EN ISO 6599-1:2026

• Abstract:

  This document specifies the conditioning atmospheres and the method for conditioning samples of intact, empty paper sacks before and during testing.

• Status: Published
• Public Enquiry End Date: 19-Nov-2025
• Publication Date: 19-Aug-2026
• ICS: 55.080 - Sacks. Bags
• Technical Committee: EPO - Packaging - sales and grouped
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 13-Aug-2026
• Due Date: 18-Oct-2026
• Completion Date: 20-Aug-2026
• Ref Project: EN ISO 6599-1:2026 - Packaging - Conditioning for testing - Part 1: Paper sacks (ISO 6599-1:2026)

• Replaces: SIST EN 26599-1:1997 - Packaging - Sacks - Conditioning for testing - Part 1: Paper sacks (ISO 6599-1:1983)
• Effective Date: 01-Sep-2026
• Refers: SIST ISO 187:2023 - Paper, board and pulps - Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples
• Effective Date: 26-Aug-2026

SIST EN ISO 6599-1:2026 is the Slovenian adoption of EN ISO 6599-1:2026 and ISO 6599-1:2026, published by SIST. It specifies the conditioning atmospheres and the method for conditioning intact, empty paper sacks before and during testing. In practice, it tells laboratories how to prepare paper sacks so they reach a controlled temperature and moisture state before performance tests.

What does SIST EN ISO 6599-1:2026 specify?

SIST EN ISO 6599-1:2026 specifies how to condition samples of intact, empty paper sacks for testing. Its scope is limited to conditioning atmospheres and the conditioning method used before and during test work, so the sacks are in a defined physical state when measured.

The document is organized into seven clauses:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Conditioning atmospheres
• Clause 5 - Equipment
• Clause 6 - Procedure
• Clause 7 - Test report

Clause 4 also notes that when only conventional paper tests are carried out on the sack material, samples cut from the material are conditioned according to ISO 187.

What are the key requirements of SIST EN ISO 6599-1:2026?

SIST EN ISO 6599-1:2026 requires empty paper sacks to be exposed to a conditioning atmosphere until they reach temperature and moisture equilibrium. That matters because the moisture content of paper changes with the surrounding air, and test results only compare well when the starting condition is controlled.

Conditioning atmospheres

Clause 4 names the standard atmospheres that may be used. The preferred atmosphere is 23/50, and the document also allows 27/65 where climate conditions at the test location make that necessary, and 20/65 as another suitable atmosphere.

In practice, this means the test plan or product specification should identify which atmosphere applies. If nothing else is stated, 23/50 is the default choice.

Equipment and control of the conditioning room

Clause 5 requires the conditioning room to have automatic equipment that brings the air to the required temperature and relative humidity and keeps it uniform throughout the space. It also recommends a recording hygrometer for checking purposes and periodic calibration.

For users, this means the conditioning space itself is part of test control, not just a storage room. Clause 5 points to ISO 187:2022 for the conditioning room specification and for temperature and relative humidity measurement data.

Conditioning procedure

Clause 6 requires the sacks to be suspended so the air can circulate freely around the outer surfaces and, for open mouth sacks, as much of the inner surface of the innermost ply as possible. The clause also says preconditioning should be omitted where it would create larger errors than it removes.

The minimum conditioning time depends on construction:

• sacks without barrier plies - at least 24 h
• sacks with one or more barrier plies - at least 7 days

If a sack is filled after conditioning, the product may change the paper moisture content, so additional equilibration time may be needed. That matters when conditioning is done before filling rather than before the final test.

Test reporting

Clause 7 requires the test report to identify the sample, the atmosphere used, the conditioning time, the document reference, the results and the clause used to calculate them, any deviations, any unusual features observed, and the test date. This gives traceability for audits, supplier comparisons and dispute resolution.

What terms does SIST EN ISO 6599-1:2026 define?

• Relative humidity (RH) - the ratio of the water vapour content of air to the content at saturation at the same temperature and pressure, usually expressed as a percentage.
• Conditioning - establishing temperature and moisture equilibrium between empty sacks and a specified atmosphere.
• Conditioning atmosphere - the controlled temperature and relative humidity used to bring the sacks to equilibrium.
• Barrier plies - layers in the sack construction that lead to the longer 7-day minimum conditioning period.
• Open mouth sacks - sacks whose open top allows conditioning air to reach part of the inner surface.
• Paper sacks - the packaging item covered by the standard, using the vocabulary of ISO 6590-1.

Who uses SIST EN ISO 6599-1:2026?

Packaging laboratories use SIST EN ISO 6599-1:2026 when they need to condition sacks before testing. Paper sack manufacturers and converters use it to prepare samples in a consistent way before internal checks or customer testing.

Quality managers, buyers and test houses use it when specifications require a defined conditioning state for comparison, acceptance testing or technical claims. It is also relevant wherever paper sack performance depends on moisture-sensitive properties.

What changed in SIST EN ISO 6599-1:2026 from the previous edition?

SIST EN ISO 6599-1:2026 is the second edition and it cancels and replaces ISO 6599-1:1983. The document states these main changes:

• the reference to ISO 554 on standard atmospheres for conditioning was deleted
• a clarification was added on omitting preconditioning
• a recommendation was added for periodic calibration of a recording hygrometer
• the test report was expanded with additional information requirements

The European edition also supersedes EN 26599-1:1992.

Which standards are used with SIST EN ISO 6599-1:2026?

• ISO 187:2022 - provides the standard atmosphere for conditioning and testing, plus guidance on monitoring the atmosphere and conditioning samples.
• ISO 6590-1 - provides the vocabulary for paper sacks used in the terminology section.

What does the SIST EN ISO 6599-1:2026 document contain?

The document contains one table of suitable conditioning atmospheres and three main technical clauses on atmosphere, equipment and procedure. Clause 4 gives the allowable temperature and relative humidity combinations, while Clause 6 gives the conditioning method and the minimum conditioning periods for sacks with and without barrier plies.

Clause 5 points users to ISO 187:2022 for conditioning room and measurement details, and Clause 7 gives the reporting items needed to document the test properly. The result is a short, practical document focused on sample preparation rather than on the mechanical tests themselves.

SLOVENSKI STANDARD
01-september-2026
Nadomešča:
SIST EN 26599-1:1997
Embalaža - Kondicioniranje za preskušanje - 1. del: Papirnate vreče (ISO 6599-
1:2026)
Packaging - Conditioning for testing - Part 1: Paper sacks (ISO 6599-1:2026)
Verpackung - Klimatische Vorbehandlung für die Prüfung - Teil 1: Papiersäcke (ISO
6599-1:2026)
Emballages - Conditionnement pour essais - Partie 1: Sacs en papier (ISO 6599-1:2026)
Ta slovenski standard je istoveten z: EN ISO 6599-1:2026
ICS:
55.080 Vreče. Vrečke Sacks. Bags
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 6599-1
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2026
EUROPÄISCHE NORM
ICS 55.080 Supersedes EN 26599-1:1992
English Version
Packaging - Conditioning for testing - Part 1: Paper sacks
(ISO 6599-1:2026)
Emballages - Conditionnement pour essais - Partie 1: Verpackung - Klimatische Vorbehandlung für die
Sacs en papier (ISO 6599-1:2026) Prüfung - Teil 1: Papiersäcke (ISO 6599-1:2026)
This European Standard was approved by CEN on 26 July 2026.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6599-1:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 6599-1:2026) has been prepared by Technical Committee ISO/TC 122
“Packaging” in collaboration with Technical Committee CEN/TC 261 “Packaging” the secretariat of
which is held by AFNOR.
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 2027, and conflicting national standards
shall be withdrawn at the latest by February 2027.
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 26599-1:1992.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 6599-1:2026 has been approved by CEN as EN ISO 6599-1:2026 without any
modification.
International
Standard
ISO 6599-1
Second edition
Packaging — Conditioning for
2026-07
testing —
Part 1:
Paper sacks
Emballages — Conditionnement pour essais —
Partie 1: Sacs en papier
Reference number
ISO 6599-1:2026(en) © ISO 2026

ISO 6599-1:2026(en)
© ISO 2026
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
ISO 6599-1:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Conditioning atmospheres . 1
4.1 General .1
4.2 Temperature and humidity .2
5 Equipment . 2
5.1 Room and measuring instrumentation .2
5.2 Determination of temperature and relative humidity .2
6 Procedure . 2
6.1 General .2
6.2 Minimum conditioning period for sacks without barrier plies .2
6.3 Minimum conditioning period for sacks with barrier plies .2
7 Test report .
...