ISO 18928:2026

• Abstract:

  This document specifies recommended storage conditions for unprocessed silver halide containing photographic materials. It is not applicable to processed films and prints. This document applies to black-and-white and colour photographic materials (e.g. negative films, positive films, reversal films, positive papers and X-ray films).

• Status: Published
• Publication Date: 27-Jul-2026
• ICS: 37.040.20 - Photographic paper, films and plates. Cartridges
• ICS: 37.040.30 - Photographic chemicals
• Technical Committee: ISO/TC 42 - Photography
• Drafting Committee: ISO/TC 42/WG 5 - Physical properties and image permanence of photographic materials
• Current Stage: 6060 - International Standard published
• Start Date: 28-Jul-2026
• Due Date: 19-Mar-2027
• Completion Date: 28-Jul-2026

• Revises: ISO 18928:2013 - Imaging materials — Unprocessed photographic films and papers — Storage practices
• Effective Date: 22-Mar-2025

ISO 18928:2026 is an International Standard from ISO for storing unprocessed silver halide containing photographic films and papers. It gives recommended storage conditions for black-and-white and colour materials, including negative films, positive films, reversal films, positive papers and X-ray films, and it is not for processed films and prints.

What does ISO 18928:2026 specify?

ISO 18928:2026 specifies how unprocessed photographic materials should be stored so their photographic properties are preserved until use or processing. The document is organized into scope, references, terms, storage conditions, temperature acclimatization, mechanical requirements, handling conditions, and Annex A on background radiation.

Annex	What it covers
Annex A	Background radiation and the relation between exposure and dose

The core topic is storage practice, not product manufacture or processing chemistry. In practice, the document is meant to help users keep unopened or partly opened film and paper in a condition that avoids fogging, blocking, brittleness, curl and other age-related damage.

What are the key requirements of ISO 18928:2026?

ISO 18928:2026 centers on controlling humidity, temperature, gases, radiation and handling so that unprocessed silver halide materials remain usable. It also gives practical guidance for package warming before opening refrigerated material.

• General storage - Clause 4.1 says ageing is affected by heat, humidity, plastics, solvents, gases and radiation. It also says opened packages should be used promptly and then resealed under recommended conditions. In practice, this means storage areas and packaging need to be chosen to avoid slow quality loss.
• Relative humidity (RH) - Clause 4.2 says materials should generally be kept in equilibrium with 40 % to 60 % RH, and the storage area should stay below 65 % RH. Humidity that is too high can damage containers and promote fungi, while humidity that is too low can make material temporarily brittle and cause curl.
• Temperature - Clause 4.3 says storage temperature depends on material type and duration. It notes short storage may be around room temperature, longer storage should be cooler, and infrared (IR) films require very low temperature storage. Table 1 gives temperature guidance by sensitive layer and storage period, so buyers and warehouse staff can match storage conditions to the stock they hold.
• Gases - Clause 4.4 requires protection from harmful gases such as hydrogen sulphide, sulfur dioxide, formaldehyde, oxidizing gases, industrial emissions and mercury vapour. The same area should not be used for developer or activator solution. This matters because gas contamination can fog or desensitize the material.
• Extraneous radiation - Clause 4.5 requires protection from penetrating radiation before processing. Annex A supports this by explaining background radiation units. The clause also points out that airport X-ray inspection can affect many unprocessed photographic products, so hand inspection is preferred where possible.
• Temperature acclimatization - Clause 5 says cold-stored packages should warm up before opening to prevent condensation. Table 2 gives minimum warm-up times for different package types and temperature differences. In practice, this avoids moisture forming on the film or paper surface.
• Mechanical and handling conditions - Clauses 6 and 7 say rolls should be stored to avoid pressure damage, larger sheet boxes should be stored vertically if unopened and horizontally if opened, and laboratory handling should control temperature, RH, dust, static, safelight exposure and physical contact. Lint-free cotton gloves are recommended to reduce fingerprints and abrasion.

Who uses ISO 18928:2026?

ISO 18928:2026 is aimed at the silver halide material supply chain and at end users. The introduction names photofinishing labs, wholesalers, retailers and others who store or distribute unprocessed material, as well as professional and amateur photographers who need to keep film and paper usable before exposure or processing.

It is also relevant to warehouse managers, quality managers and buyers who need to specify storage rooms, package handling, refrigeration, humidity control or airport transport procedures for photographic stock.

What changed in ISO 18928:2026 from the previous edition?

ISO 18928:2026 is the fourth edition and cancels and replaces ISO 18928:2013. The document states these main changes:

• typographical errors were corrected in Annex A;
• the text now makes specific reference to silver halide products to distinguish them from other imaging materials;
• references and storage conditions were updated to reflect contemporary sensitised products;
• the short-term storage condition was revised to align with current black-and-white film recommendations;
• a note was added on the long-term benefits of refrigerator storage.

Which standards are used with ISO 18928:2026?

ISO 18928:2026 sits alongside other ISO 18900-series storage documents for related photographic materials. The introduction and bibliography name these related standards:

• ISO 18911 - storage practices for processed safety photographic films
• ISO 18918 - storage practices for processed photographic plates
• ISO 18920 - storage practices for reflection prints
• ISO 18906 - specifications for safety film

These documents help users apply the right storage practice to processed or safety-film materials rather than to unprocessed film and paper.

What does the ISO 18928:2026 document contain?

The document contains general storage guidance, temperature and humidity recommendations, gas and radiation precautions, acclimatization guidance, and handling instructions. It also includes Table 1 for storage temperature guidance and Table 2 for warm-up times before opening cold-stored packages.

Annex A explains background radiation and the difference between exposure and dose in relation to photographic materials. The bibliography points readers to related ISO standards and one technical paper on radiation protection for medical X-ray film.

International
Standard
ISO 18928
Fourth edition
Imaging materials — Unprocessed
2026-07
photographic films and papers —
Storage practices
Matériaux pour l'image — Films et papiers photographiques non
traités — Pratiques de stockage
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 Storage conditions . 1
4.1 General .1
4.2 Relative humidity .1
4.3 Temperature .2
4.4 Gases .2
4.5 Extraneous radiations .2
5 Temperature acclimatization . 3
6 Mechanical requirements . 3
7 Handling conditions . 3
Annex A (informative) Background radiation . 5
Bibliography . 6

iii
Foreword
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Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 42, Photography.
This fourth edition cancels and replaces the third edition (ISO 18928:2013) which has been technically
revised.
The main changes are as follows:
— typographical errors corrected in Annex A;
— specific reference made to silver halide products to distinguish these from other imaging materials.
— updates to references and storage conditions to reflect contemporary sensitised products. Specifically,
the short-term storage condition has been revised down from 21 °C to the recommendations on current
Black and White films. A note has been added on the long-term benefits of storage in a refrigerator.
A list of all parts in the ISO 18900 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
International Standards have been written specifying the recommended practices for the storage of the
following chemically processed silver halide products:
— safety photographic film (see ISO 18911);
— reflection prints (see ISO 18920);
— photographic plates (see ISO 18918).
This document is concerned with the storage of unprocessed silver halide photographic materials. While
many of the recommendations for unprocessed and processed storage are very similar, there are some
important differences. These include the very beneficial effects of low temperature and the harmful effects
of adverse storage and radiation. ISO guidance is that each document should explicitly consider the relevant
stakeholders. The stakeholders identified in this project are
— photofinishing labs, wholesalers, retailers and others in the silver halide material supply chain, and
— end users of silver halide materials such as professional and amateur photographers.
The ISO commitment to the consideration of climate science is embodied in the London Declaration. In line
with this, some guidance is given on the effect of high temperature events on storage conditions.

v
International Standard ISO 18928:2026(en)
Imaging materials — Unprocessed photographic films and
papers — Storage practices
1 Scope
This document specifies recommended storage conditions for unprocessed silver halide containing
photographic materials. It is not applicable to processed films and prints.
This document applies to black-and-white and colour photographic materials (e.g. negative films, positive
films, reversal films, positive papers and X-ray films).
2 Normative references
There are no normative r
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