SIST ISO 18938:2014

INTERNATIONAL ISO
STANDARD 18938
Second edition
2014-09-15
Imaging materials — Optical discs
— Care and handling for extended
storage
Matériaux pour l’image — Disques optiques — Précautions et
manipulation pour stockage étendu
Reference number
ISO 18938:2014(E)
©
ISO 2014

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ISO 18938:2014(E)

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© ISO 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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Published in Switzerland
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ISO 18938:2014(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Composition of optical discs . 6
4.1 General . 6
4.2 Polycarbonate substrate (plastic) layer . 6
4.3 Data layer . 6
4.4 Reflective layer . 7
4.5 Protective layers . 7
4.6 Adhesive layers . 7
4.7 Additional layers. 8
5 Failure mechanisms . 8
5.1 General . 8
5.2 Physical stress. 8
5.3 Layer sensitivity . 8
5.4 Scratches . 9
5.5 Effects of disc play . 9
6 Handling techniques .10
6.1 General .10
6.2 Flexing .10
6.3 Contamination .10
6.4 Disc enclosures .10
7 Identification .11
7.1 Basic concepts .11
7.2 Adhesive labels .11
7.3 Printing on optical discs .11
7.4 Thermal printing .12
7.5 Inkjet printable surface .12
7.6 Silk screening .12
7.7 Marking .12
8 Contamination .12
8.1 Fingerprints, smudges, dirt, dust .12
8.2 Moisture .12
8.3 Organic solvents .13
8.4 Gaseous impurities .13
8.5 Consumables .13
9 Use environment .13
9.1 General .13
9.2 Temperature and humidity .13
9.3 Water avoidance .14
9.4 Air quality .14
9.5 Light exposure .14
9.6 Acclimatization .15
9.7 Vibrations .15
10 Transportation and shipping .15
10.1 Enclosures .15
10.2 Cartons .15
10.3 Exposure .16
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ISO 18938:2014(E)

10.4 Security .16
10.5 External fields .16
10.6 Biological irradiation .16
11 Inspection .16
11.1 General requirements .16
11.2 Error rate monitoring .17
12 Cleaning and maintenance .17
12.1 General .17
12.2 Solvents and cleaning compounds .17
12.3 Cleaning methods .17
13 Disasters .18
13.1 General .18
13.2 Water .18
13.3 Fire . .18
13.4 Dry debris .18
13.5 Impact from disasters .19
13.6 Repair .19
14 Disaster response .19
14.1 General .19
14.2 Wet discs .19
14.3 Dry discs .19
15 Staff training .19
15.1 General .19
15.2 Purpose .20
15.3 Training paths .20
15.4 Schedule for training .20
15.5 Update of training .20
15.6 Content of training .20
16 Minimum handling requirements checklist .21
16.1 General .21
16.2 Do list .21
16.3 Not-to-do list .21
Annex A (informative) Disc structure .23
Bibliography .25
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ISO 18938:2014(E)

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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on
the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO 18938:2008), which has been technically
revised.
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ISO 18938:2014(E)

Introduction
In addition to storage conditions, the proper care and handling of optical discs is also vital to prolonged
disc life. This is becoming increasingly important as optical discs are widely used for the recording and
storage of information. This International Standard gives guidelines for their recommended care and
handling and will be beneficial for all digital optical discs, regardless of their inherent stability.
NOTE It is recognized that both “optical discs” and “optical disks” are acceptable spellings. In this International
Standard, the former spelling is used.
Probably no form of data storage has been accepted and adopted as rapidly as the optical disc. It has
become the medium of choice for numerous applications with ever increasing use for the recording and
storage of information. Information is recorded in digital format that not only provides high storage
density, but also allows duplication without information loss, ease of data manipulation and facilitates
transmission. It is of tremendous benefit for audio usage since it permits uninterrupted playback for
long periods of time. Information in a disc format can be accessed very quickly, unlike that in a roll
format such as magnetic tape, which requires longer search time.
While the advantages are many, as with other media, there are nevertheless concerns about the life
expectancy of recorded information on optical discs. This depends upon three independent components,
namely the permanence of the disc itself, the disc drive and the software. Obsolescence of the disc drive
and software, lack of playback device or inoperability of the playback device are all serious uncertainties.
Another important issue is the quality of the initial data recorded onto the disc, which needs to be
as high as possible. In addition, the very popularity of recordable optical discs has led to their wide
availability, and wide variability in the quality of discs for long term preservation of information. Many
discs may not be of sufficient quality for long term use.
The finite life of optical discs is well recognized and one approach to addressing this issue is by
periodically transferring or reformatting the information. In addition, the ability to play back a disc in
the future depends on the existence of functional playback equipment. As newer formats and equipment
become popular, equipment manufacturers will probably discontinue production and support of the
older, superseded equipment. Eventually, usable equipment to play obsolete optical disc formats will
become difficult to find. Before this occurs, it is advisable that a migration plan be in place. However, these
issues are outside the scope of this International Standard, which is only concerned with the stability of
the optical disc itself. A primary objective of those involved with the preservation of information on this
media is to ensure that the disc is not the weak link among the necessary components. To support this
objective, it is advisable that steps be taken to maximize the optical disc’s potential to be more stable
than either the hardware or the software.
As with paper records, photographic film and magnetic tape, optical discs are subject to both damage
and decay. They have a finite life. Predictions of the life expectancy of optical discs have involved
extrapolations of property retention after high temperature and humidity incubations back to practical
conditions. These extrapolations follow mathematical treatments that were developed for simpler
chemical reactions, and therefore the results need to be interpreted with some caution. Predictions cover
a very wide range, from 25 years to over 250 years, which vary with the manufacturer and the disc type.
Their effective life can be increased or decreased significantly depending upon the conditions under
which they are stored. Storage recommendations for optical discs are given in ISO 18925. Following
these recommendations promotes the physical integrity of the media and increases their effective life.
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INTERNATIONAL STANDARD ISO 18938:2014(E)
Imaging materials — Optical discs — Care and handling for
extended storage
1 Scope
This International Standard establishes general principles for the care and handling of digital optical
discs during use. It addresses the issues of physical integrity of the medium necessary to preserve access
to the recorded data (information). This International Standard includes recommendations for handling
procedures to maximize the effective life of optical discs. Faulty handling, packing and transporting
techniques and methods often cause physical damage to the discs and to the content recorded thereon.
Extending the longevity of optical discs requires the identification of appropriate handling methods, as
well as well-developed and implemented training programs.
For the purposes of this International Standard, the term “optical disc” includes the families of compact
disc (CD), digital versatile disc (DVD), high definition digital versatile disc (HD DVD) and Blu-ray disc
1)
(BD) , and any hybrids of these families. The term “optical disc” also includes each type of disc within
a family, including injection moulded [read-only memory (ROM)], dye-layer [recordable (R)] and phase
change [rewritable (RW, RE), random access memory (RAM), and recordable (BD-R)] technologies.
While some of the recommendations in this International Standard (e.g. those for staff training) apply
specifically to large-scale or long term usage, the basics of all recommendations in this International
Standard are intended to be applied in circumstances where the desired result is long-term usage of the
medium whether archival, commercial or personal.
This International Standard does not cover magneto-optical (MO) discs, laser discs (LD) or glass discs.
At the time of writing, International Standards do not exist for HD DVD and Blu-ray discs. Nonetheless,
it is believed that the recommendations in this International Standard for care and handling can equally
apply to them. It is recognized that some of these requirements are not necessarily possible for the
individual user to achieve.
The following are within the scope of this International Standard:
— use and handling environments, including pollutants, temperature and humidity and light exposure;
— contamination concerns;
— inspection;
— cleaning and maintenance, including cleaning methods and frequency;
— transportation;
— disasters, including water, fire, construction and post-disaster procedures;
— staff training.
The quality of the data written on the disc is outside the scope of this International Standard. However,
a high quality result of the recording phase is important to the longevity of information. It is advisable
that a rigorous program of data integrity testing be implemented, as this forms an obligatory part of
all digital long-term storage. In addition, when keeping digital information for archival purposes, it is
advisable that a multiple copy/multiple location strategy be in place.
TM TM
1) Blu-ray Disc and Blu-ray are trademarks of Blue-ray Disc Association, and Blu-ray Disc and HD DVD are
examples of suitable products available commercially. This information is given for the convenience of users of this
International Standard and does not constitute an endorsement by ISO of these products.
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ISO 18938:2014(E)

2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 14644-1, Cleanrooms and associated controlled environments — Part 1: Classification of air cleanliness
by particle concentration
ISO 18925, Imaging materials — Optical disc media — Storage practices
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
acclimatization staging
process of conditioning material from one set of temperature-moisture conditions to another
3.2
balance
precision vertical position of the disc as it spins
3.3
blister
localized delamination that looks like a bubble
3.4
Blu-ray Disc
BD
optical disc having a cover layer around 0,1 mm thick and a substrate around 1,1 mm thick on which
data is read or recorded by an OPU using 405 nm laser diode and NA = 0,85 lens
3.4.1
Blu-ray Disc Read Only Memory
BD-ROM
optical disc to which information is transferred during manufacture to moulded areas in the Blu-ray
disc format and can be read multiple times by an optical beam
3.4.2
Blu-ray Disc Recordable
BD-R
recordable optical disc in which information can be recorded once to areas in the Blu-ray disc format
and read many times
3.4.3
Blu-ray
...