ISO 18925:2002

Imaging materials - Optical disc media - Storage practices

Matériaux pour l'image — Milieu pour disque optique — Pratiques de stockage

General Information

• Status: Withdrawn
• Publication Date: 20-Feb-2002
• Withdrawal Date: 20-Feb-2002
• ICS: 37.040.99 - Other standards related to photography
• Technical Committee: ISO/TC 42 - Photography
• Drafting Committee: ISO/TC 42/WG 5 - Physical properties and image permanence of photographic materials
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 06-Oct-2008
• Directive: TP152 - Uredba o varstvu dokumentarnega in arhivskega gradiva

Relations

• Revised: ISO 18925:2008 - Imaging materials — Optical disc media — Storage practices
• Effective Date: 15-Apr-2008

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 18925
First edition
2002-02-15


Imaging materials — Optical disc media —
Storage practices
Matériaux pour l'image — Milieu pour disque optique — Pratiques de
stockage




Reference number
ISO 18925:2002(E)
©
 ISO 2002

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ISO 18925:2002(E)
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ii © ISO 2002 – All rights reserved

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ISO 18925:2002(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .2
4 Environmental conditions.4
4.1 Humidity and temperature limits.4
4.2 Contaminants and gaseous impurities .5
4.3 Magnetic fields.5
5 Materials.5
6 Enclosures.5
6.1 General requirements.5
6.2 Labelling.5
7 Preparation.6
7.1 General.6
7.2 Acclimatization.6
8 Storage housing.6
9 Storage rooms.6
10 Fire-protective storage.7
11 Identification, inspection and cleaning .7
11.1 Identification.7
11.2 Inspection.7
11.3 Cleaning.8
Annex A (informative) Numbering system for related International Standards .9
Annex B (informative) Temperature-relative humidity relationship.11
Annex C (informative) Temperature and humidity acclimatization.12
Bibliography.13



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ISO 18925:2002(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
The main task of technical committees is to prepare International Standards. Draft International Standards adopted
by the technical committees are circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18925 was prepared by Technical Committee ISO/TC 42, Photography.
This International Standard is one of a series of standards dealing with the physical properties and stability of
imaging materials. To facilitate identification of these International Standards, they are assigned a number within
the block from 18900 to 18999 (see annex A).
Annexes A to C of this International Standard are for information only.
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ISO 18925:2002(E)
Introduction
Use of optical disc material is becoming widespread in audio, video and computer applications. Preservation of this
information is becoming of increasing concern to society, particularly as the recorded information becomes older
and frequently of greater value to libraries, archives, museums, government agencies and commercial
organizations.
The stability of optical discs is dependent upon that of the complete system. This includes the stability of the
material itself, the equipment on which it is run and, in systems, upon the necessary software. ISO 18921, Compact
discs (CD-ROM) — Method for estimating the life expectancy based on the effects of temperature and relative
humidity specifies a methodology for estimating the life expectancy of the CD-ROM. Other optical discs will be
addressed in future International Standards. These standards consider only the effects of temperature and humidity
and do not include other factors such as light, corrosive gases and particulates. International Standards are not
available on the life expectancy of hardware and the problems associated with hardware wearing out or becoming
obsolete.
Optical disc users should store discs under conditions that will extend their life and should handle the material so
that it will not be subjected to stress and undergo physical breakdown during use. This International Standard
addresses the concerns of long-term storage.
A major component of a large number of optical discs is the polycarbonate substrate. Polycarbonate is a very
durable material, but it does absorb moisture and there is always an equilibrium between the ambient humidity and
the moisture content of the disc. Polycarbonate is susceptible to decomposition under certain conditions and given
a suitable catalyst.
The second component of most optical discs is the reflective layer. This layer is usually some highly reflective metal
such as aluminium, silver or gold. Each of these materials is subject to reaction with various chemicals that may be
found in the environment. Aluminium, for example, combines readily with oxygen to form aluminium oxide. Silver
combines with sulfur to tarnish and form silver sulfides. Gold is known to react with chlorine to form gold chlorides.
A third component of these discs is some type of seal coat. This is typically a UV-cured polymer whose purpose is
to protect the reflective layer and any other material layers in the disc.
A fourth component, in the case of some recordable optical discs, is the dye layer. For magneto-optic or phase
change discs, additional layers are also included.
Regardless of the inherent stability of the various disc layers, it is known that good storage conditions will extend
the life of all optical discs. While a good storage environment cannot reverse any degradation that has already
occurred, it can slow down additional deterioration.
A single storage condition is described in this International Standard. This condition is intended for discs that
contain recorded information of long-term value. Various manufacturers’ studies indicate that the life expectancy of
well manufactured optical discs is in excess of 50 years under typical room ambient conditions (see [1] and [2] in
the Bibliography).


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INTERNATIONAL STANDARD ISO 18925:2002(E)

Imaging materials — Optical disc media — Storage practices
1 Scope
This International Standard establishes extended-term storage conditions for optical discs and provides
recommendations concerning the storage conditions, storage facilities, enclosures and inspection for optical discs.
It is applicable to discs made for audio, video, instrumentation and computer use.
Recommendations are general in nature and the manufacturer's cautions for specific material should be
considered. Relaxation from these recommendations, whether before or after recording, will generally result in
shortened life expectancy.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this International Standard. For dated references, subsequent amendments to, or revisions of, any of these
publications do not apply. However, parties to agreements based on this International Standard are encouraged to
investigate the possibility of applying the most recent editions of the normative documents indicated below. For
undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC
maintain registers of currently valid International Standards.
ISO/IEC 10149:1995, Information technology — Data interchange on read-only 120 mm optical disks (CD-ROM)
ISO/IEC 15486:1998, Information technology — Data interchange on 130 mm optical disc cartridges of type
WORM (Write Once Read Many) using irreversible effects — Capacity: 2,6 Gbytes per cartridge
1)
ISO 18921:— , Imaging materials — Compact discs (CD-ROM) — Method for estimating the life expectancy
based on the effects of temperature and relative humidity
ISO 18923:2000, Imaging materials — Polyester-base magnetic tape — Storage practices
IEC 60908:1999, Compact disc digital audio system
2)
NFPA 75-1995, Electronic computer/Data processing equipment
2)
NFPA 232-1995, Protection of records
3)
UL 72-1990, Tests for fire resistance of record protection equipment




1) To be published.
2) Available from the National Fire Protection Association, 1 Batterymarch Park, P.O. Box 9101, Quincy, MA 02269-9101,
USA.
3) Available from the Underwriters Laboratories, 333 Pfingsten Road, Northbrook, IL 60062, USA.
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ISO 18925:2002(E)
4)
X3.212-1995, Information systems — 130 mm rewritable optical disc cartridge for information interchange
5)
Japanese Ordinance No. 306, Regulation on fire-hazard materials under Fire Protection Law
6)
JIS S 1037: 1998, Fire-resistive containers
3 Terms and definitions
For the purposes of this International Standard, the following terms and definitions apply.
3.1
blister
localized delamination that looks like a bubble
3.2
compact disc
CD
optical disc format in which the information layer is located at one surface of a substrate and the data can be read
by an optical beam
NOTE CD is the subject of IEC 60908.
3.2.1
compact disc-recordable
CDR
recordable optical disc in which information can be recorded to certain areas in the compact disc format
NOTE Information can be recorded one time and read many times.
3.2.2
compact disc read-only memory
CD-ROM
optical disc to which information is transferred during manufacture to certain areas in the compact disc format
NOTE 1 Information can be read many times.
NOTE 2 CD-ROM is the subject of ISO/IEC 10149.
3.2.3
compact disc-rewritable
CD-RW
recordable optical disc in which information can be recorded to certain areas in the compact disc format
NOTE Information can be erased and new information recorded many times and read many times.
3.3
container
box, can, or carton used for storage and shipping of recording materials

4) Available from the National Committee for Information Technology Standards, 125 Eye St., NW, Suite 200, Washington, DC
20005, USA, e-mail: [e-mail].
5) Available from the Center for Governmental Issues Services, Building No. 2 of the Ohtemachi-Godo-Chosha Governmental
Offices, Chiyoda-ku, Ohtemachi 1-3-2, Tokyo, Japan.
6) Available from the Japanese Standards Association, Minato-ku, Akasaka 4-1-14, Tokyo, 107, Japan.
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ISO 18925:2002(E)
3.4
digital versatile disc
DVD
digital video disc (superseded)
optical disc format in which one or more information layers are located between two substrates and the data can be
read by an optical beam
3.5
delamination
separation of a laminate into its constituent layers
3.6
dew point
temperature at which moisture begins to condense on a surface
See relative humidity (3.16)
EXAMPLE The more humid the air, the higher the dew point temperature.
3.7
enclosure
folder, envelope, sleeve or clam shell intended for physical protection against mechanical damage
3.8
extended-term storage conditions
storage conditions suitable for the preservation of recorded information having permanent value
3.9
fire-protective storage
facilities designed to protect records against excessive temperatures, water and other fire-fighting agents, and
steam developed by insulation of safes or caused by the extinguishing of fires and collapsing structures
3.10
insulated record container
storage box designed to withstand elevated temperatures and conforming to national standards and regulations
3.11
isoperm lines
lines of constant life plotted as a function of temperature and relative humidity
3.12
life expectancy
LE
length of time that information is predicted to be retrievable in a system at 21 °C and 50 % RH
3.13
magnetic field intensity
level of the magnetic field at a point in space
3.14
medium
material on which the information is recorded
NOTE Plural is media.
3.15
MO disc
optical disc in which the information is recorded using magneto-optical technology in some specified format
NOTE Information can be recorded, read many times and overwritten many times.
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ISO 18925:2002(E)
3.16
relative humidity
RH
ratio, defined as a percentage, of the existing partial vapour pressure of water to the vapour pressure at saturation
NOTE It is usually, but not always, equal to the percentage of the amount of moisture in the air to that at saturation.
3.17
storage environment
conditions for storing materials, i.e. temperature, relative humidity, cleanliness of facilities and atmospheric
pollutants
3.18
storage housing
physical structure supporting materials and their enclosures
NOTE It may consist of drawers, racks, shelves or cabinets.
3.19
system
combination of material, hardware, software and documentation necessary for recording and/or retrieving
information
3.20
WORM disc
optical disc in which the data in specified areas can be written only once and read multiple times by an optical
beam
4 Environmental conditions
4.1 Humidity and temperature limits
The average relative humidity of an extended-term storage environment shall be maintained between 20 % RH and
50 % RH. Cycling of relative humidity shall not be greater than ± 10 %. Ideally, the maximum temperature for
extended periods should not exceed 25 °C, and a temperature below 23 °C is preferable. The peak temperature
shall not exceed 32 °C. Generally, useful life will be increased by storing discs at low temperature and low relative
humidity, since chemical degradation is reduced at these conditions (see annex B). Storage of discs below − 10 °C
and below 10 % RH is not recommended.
Specific manufacturer’s recommendations, when available, should take precedence over the above general
recommendations.
For any facility, it is impossible to specify what the best relative humidity and storage temperature should be, since
it depends upon the value of the material, the past storage history, the length of time the disc is to be kept, the size
of the vault, the cost of various options and the climate conditions where the facility is located.
Lower temperatures within the specified relative humidity range can be difficult to achieve with normal humidity air-
conditioning equipment and may require a specialized installation. Automatic control systems are recommended,
and they shall be checked frequently enough to determine that the specified temperature and humidity limits are
not being exceeded. A reliable hygrometer can be used for humidity measurements.
Where air conditioning is not practical, high humidities may be lowered by electrical refrigeration-type dehumidifiers
controlled with a hygrostat. Inert desiccants, such as chemically pure silica gel, may be used, provided the
dehumidifier is equipped with filters capable of removing dust particles down to 0,3 µm (micrometres) in size and is
controlled to maintain the relative humidity within the specified range. Dehumidification may be required in storage
areas such as basements and caves which have inherently low temperatures but which frequently exceed the
upper humidity limit.
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ISO 18925:2002(E)
The recommended humidity and temperature conditions can be maintained either within individual storage
housings or within storage rooms containing such housings.
4.2 Contaminants and gaseous impurities
Contaminants can pass through very small cracks or scratches in protective layers, react with reflective or
recording layers in the disc and potentially cause loss of data. Best available technologies shall be used t
...