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
• Publication Date: 23-Jul-2026
• ICS: 55.080 - Sacks. Bags
• Technical Committee: ISO/TC 122/SC 3 - Performance requirements and tests for means of packaging, packages and unit loads (as required by ISO/TC 122)
• Drafting Committee: ISO/TC 122/SC 3/WG 11 - Paper bags and paper sacks
• Current Stage: 6060 - International Standard published
• Start Date: 24-Jul-2026
• Due Date: 19-Dec-2026
• Completion Date: 24-Jul-2026

• Consolidates: EN ISO 6599-1:2026 - Packaging - Conditioning for testing - Part 1: Paper sacks (ISO 6599-1:2026)
• Effective Date: 12-Feb-2026
• Consolidates: ISO/IEC TR 63306-2:2021 - Smart manufacturing standards map (SM2) — Part 2: Catalogue
• Effective Date: 28-Jun-2025
• Revises: ISO 6599-1:1983 - Packaging — Sacks — Conditioning for testing — Part 1: Paper sacks
• Effective Date: 21-Jun-2025

ISO 6599-1:2026 is an International Standard published by ISO for conditioning intact, empty paper sacks before and during testing. It specifies the conditioning atmospheres to use, the conditioning method, the required equipment, and the minimum conditioning periods so sacks are brought to a defined moisture state before test results are taken.

What does ISO 6599-1:2026 specify?

ISO 6599-1:2026 specifies how to condition samples of intact, empty paper sacks for test work. It covers the atmosphere, the room and instruments needed, the procedure to follow, and the information to record in the test report.

The scope is limited to paper sacks. The document also notes that if only conventional paper tests are performed on sack material, that material is cut out and conditioned in line with ISO 187.

The document is organized into:

• 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

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

ISO 6599-1:2026 requires empty sacks to be exposed to a conditioning atmosphere until they reach temperature and moisture equilibrium. In practice, this is what makes the sack state defined and repeatable before testing.

Conditioning atmospheres

Clause 4.2 identifies the usual conditioning atmosphere as 23/50 unless a test method, specification, or agreement between the interested parties says otherwise. The other suitable atmospheres listed are 27/65 and 20/65. For a laboratory, this means the test environment must be chosen deliberately and reported, because the atmosphere affects moisture content and therefore test behavior.

Room and measurement control

Clause 5 requires the conditioning room to have automatic control of temperature and relative humidity, with air circulation that keeps conditions uniform at all relevant points. A recording hygrometer should be kept in the space and periodically calibrated. Clause 5 also points to ISO 187:2022 for room specification details and for temperature and relative humidity data.

Procedure for suspending and conditioning sacks

Clause 6 says the sacks shall be suspended so air can circulate freely over all outer surfaces and, for open mouth sacks, to as much of the inner surface of the innermost ply as possible. This matters because poor air circulation can leave parts of the sack out of equilibrium and distort test results.

Clause 6 also says that if the sack is filled after conditioning, the product may change the paper moisture content, so further moisture equilibration may be needed. It also states that preconditioning shall be omitted when it would create larger errors than it removes.

Minimum conditioning periods

Clause 6 gives a minimum of 24 h for sacks without barrier plies and 7 days for sacks with one or more barrier plies. In practice, barrier constructions need longer time for moisture to stabilize, so test planning and turnaround times must account for that.

Test report content

Clause 7 requires the report to identify the sample, the atmosphere used, the conditioning time, the document reference, the result(s) and how they were calculated, any deviations, unusual features, and the test date. That gives traceability for quality records, disputes, and inter-laboratory comparison.

What terms does ISO 6599-1:2026 define?

Relative humidity (RH) is the ratio of the absolute humidity of air to the humidity of saturated air at the same temperature and pressure. In this standard, RH is the key control variable together with temperature.

Conditioning is the establishment of temperature and moisture content equilibrium between empty sacks and an atmosphere of specified temperature and relative humidity. In practice, this is the stabilization step before testing.

Conditioning atmosphere is the controlled air environment used to bring the sacks to equilibrium. The document uses designated atmospheres such as 23/50, 27/65, and 20/65.

Empty sacks are the paper sacks to be conditioned before testing. The standard is written for sacks in this state, rather than filled sacks.

Barrier plies are ply layers that slow moisture exchange. Their presence is why the standard gives a much longer minimum conditioning period.

Who uses ISO 6599-1:2026?

ISO 6599-1:2026 is used by packaging test laboratories, paper sack manufacturers, and quality-control teams that need a consistent pre-test conditioning method. It is also relevant to buyers and specifiers who require test results from paper sacks to be generated under a defined atmosphere. The standard matters whenever test data for sack performance must be comparable across sites, batches, or suppliers.

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

ISO 6599-1:2026 is the second edition and cancels and replaces ISO 6599-1:1983. ISO 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

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

ISO 187:2022 provides the standard atmosphere for conditioning and testing paper, board and pulps, plus the procedure for monitoring the atmosphere and conditioning samples. ISO 6599-1:2026 uses it for room specification details, temperature and relative humidity data, and for conditioning sack material cut out for conventional paper tests.

ISO 6590-1 provides the vocabulary for packaging - paper sacks. ISO 6599-1:2026 uses it for shared terminology so users and laboratories apply the same words in the same way.

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

ISO 6599-1:2026 contains a conditioning atmosphere table, room and instrumentation requirements, a step-by-step conditioning procedure, and a test report list. The table identifies the standard atmosphere designations used in practice, while the procedure explains how to suspend sacks and how long to condition them.

The document is set up for laboratory and quality-control use, not for product design. Its contents support repeatable testing by defining the environment, the handling method, and the reporting information needed to trace the conditioning step.

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 2026
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: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
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 . 3

iii
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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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
...

Norme
internationale
ISO 6599-1
Deuxième édition
Emballages — Conditionnement
2026-07
pour essais —
Partie 1:
Sacs en papier
Packaging — Conditioning for testing —
Part 1: Paper sacks
Numéro de référence
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2026
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
Case postale 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Genève
Tél.: [phone]
E-mail: [e-mail]
Web: www.iso.org
Publié en Suisse
ii
Sommaire Page
Avant-propos .iv
Introduction .v
1 Domaine d'application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Atmosphères de conditionnement . 2
4.1 Généralités .2
4.2 Température et humidité .2
5 Appareillage . 2
5.1 Local et appareils de mesure .2
5.2 Détermination de la température et de l'humidité relative .2
6 Mode opératoire . 2
6.1 Généralités .2
6.2 Période minimale de conditionnement pour les sacs sans couches barrières .3
6.3 Période minimale de conditionnement pour les sacs ayant des couches barrières .3
7 Rapport d'essai . 3

iii
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux
de normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général
confiée aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire
partie du comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (IEC) en ce qui concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier, de prendre note des différents
critères d'approbation requis pour les différents types de documents ISO. Le présent document
a été rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
L'ISO attire l'attention sur le fait que la mise en application du présent document peut entraîner l'utilisation
d'un ou de plusieurs brevets. L'ISO ne prend pas position quant à la preuve, à la validité et à l'applicabilité de
tout droit de brevet revendiqué à cet égard. À la date de publication du présent document, l'ISO n'avait pas
reçu notification qu'un ou plusieurs brevets pouvaient être nécessaires à sa mise en application. Toutefois,
il y a lieu d'avertir les responsables de la mise en application du présent document que des informations
plus récentes sont susceptibles de figurer dans la base de données de brevets, disponible à l'adresse
www.iso.org/brevets. L'ISO ne saurait être tenue pour responsable de ne pas avoir identifié de tels droits de
brevet.
Les appellations commerciales éventuellement mentionnées dans le présent document sont données pour
information, par souci de commodité, à l'intention des utilisateurs et ne sauraient constituer un engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l'ISO liés à l'évaluation de la conformité, ou pour toute information au sujet de l'adhésion de
l'ISO aux principes de l'Organisation mondiale du commerce (OMC) concernant les obstacles techniques au
commerce (OTC), voir www.iso.org/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 122, Emballages, sous-comité SC 3,
Exigences d'aptitude à l'emploi et méthodes d'essais des procédés d'emballages, des emballages et des charges
unitaires, en collaboration avec le comité technique CEN/TC 261, Emballage, du Comité européen de
normalisation (CEN), conformément à l'Accord de coopération technique entre l'ISO et le CEN (Accord de
Vienne).
...