ISO 18911:2010

INTERNATIONAL ISO
STANDARD 18911
Second edition
2010-09-01

Imaging materials — Processed safety
photographic films — Storage practices
Matériaux pour l'image — Films photographiques de sécurité traités —
Techniques d'archivage




Reference number
ISO 18911:2010(E)
©
ISO 2010

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ISO 18911:2010(E)
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ISO 18911:2010(E)
Contents Page
Foreword .iv
Introduction.v
0.1 General .v
0.2 Nature of the photographic film.v
0.3 Photographic processing of the film.v
0.4 Storage conditions .v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Film enclosures .3
4.1 Requirements.3
4.2 Film in roll format .3
4.3 Film in sheet and slide format.4
5 Storage housings .5
6 Storage rooms .5
6.1 Medium-term storage rooms.5
6.2 Extended-term storage rooms .5
7 Environmental conditions .6
7.1 Temperature and humidity specifications for storage .6
7.2 Air-conditioning requirements.9
7.3 Air purity.10
7.4 Light.10
8 Fire-protective storage.10
9 Film identification, handling and inspection .11
9.1 Identification .11
9.2 Handling .11
9.3 Inspection.11
Annex A (informative) Distinction between storage (record) copies and work (reference) copies .12
Annex B (informative) Advantages and disadvantages of protective (sealed) enclosures .14
Annex C (informative) Air-entrained and gaseous impurities .15
Annex D (informative) Humidity during storage .16
Annex E (informative) Temperature during storage.17
Annex F (informative) Temperature/relative humidity relationship .18
Annex G (informative) Microenvironments .20
Annex H (informative) Silver image degradation.21
Annex I (informative) Fire protection .22
Bibliography.23

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ISO 18911:2010(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 2.
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 document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18911 was prepared by Technical Committee ISO/TC 42, Photography.
This second edition cancels and replaces the first edition (ISO 18911:2000), which has been technically
revised.
This International Standard is one of a series of International 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 ISO 18900 to ISO 18999.
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ISO 18911:2010(E)
Introduction
0.1 General
The value of records used in archives, museums, libraries, government, commerce and universities has
focused attention on the care of these records to ensure their longest possible life (see References [1][2][3]).
Photographic film is an important documentary and pictorial material, and there is a recognized need for
information on safeguarding photographic film having legal, scientific, industrial, artistic or historical value.
Films are susceptible to degradation from many sources. These factors can be divided into three general
categories as described below.
0.2 Nature of the photographic film
The stability of photographic film records depends on the physical and chemical nature of the film. The
specification for safety photographic film which is suitable for storage is described in ISO 18906.
For preservation purposes, processed photographic films are classified according to their life expectancy (LE)
or LE designation. These are specified in the appropriate International Standards. The term “archival” is no
longer specified to express longevity or stability in International Standards on imaging materials, since it has
been interpreted to have many meanings that range from “preserving information forever” (which is
unattainable) to “temporary storage of actively used information”.
For optimum preservation of photographic information, it is advisable that a high LE film be used and that it be
stored under extended-term storage conditions. A film material suitable for preservation is silver-gelatine-type
film on polyester base that meets the requirements of ISO 18901. However, this International Standard also
applies to processed colour, diazo (see ISO 18905), vesicular (see ISO 18912) and thermally processed silver
(see ISO 18919) films. Although these film types sometimes do not have as high an LE designation, excellent
keeping properties have been obtained with many of them.
0.3 Photographic processing of the film
For black-and-white silver-gelatine-type film, ISO 18901 specifies a maximum residual thiosulfate level for
different LE classifications and a residual silver compounds level.
For diazo film, ISO 18905 specifies a proper development test. ISO 18912, for vesicular film, includes both a
proper development test and a residual diazonium salt test.
0.4 Storage conditions
The conditions under which safety photographic film records are stored are extremely important for the
preservation of film and are the subject of this International Standard (see also ISO 18906). The same
environmental conditions are advisable for nitrate-base films, but it is advisable that they be stored in a
separate storage area having suitable fire protection safeguards (see Reference [4]).
The important elements affecting preservation of processed film are humidity, temperature and air pollutants,
as well as the hazards of fire, water, light, fungal growth, insects, microbiological attack, contact with certain
chemicals in solid, liquid or gaseous form, and physical damage. Direct contact with other generic types of film
can be detrimental to either film.
The extent to which humidity, temperature and atmospheric contaminants, or variations thereof, can be
permitted to reach beyond recommended limits without producing adverse effects will depend upon the
duration of exposure, the biological conditions conducive to fungal growth, and the accessibility of this
atmosphere to the emulsion and support surfaces. Exposure to high temperatures, and in particular to high
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ISO 18911:2010(E)
humidities, can lead to degradation of the film support and the photographic emulsion (see
References [5][6][7]). Cellulose ester-base films are more subject to base degradation than polyester-base
films.
There are two levels of storage conditions:
⎯ medium-term, and
⎯ extended-term.
Medium-term storage can be used for films where the information is to be preserved for a minimum of
10 years, while extended-term storage conditions can extend the useful life of a majority of freshly processed
films to 500 years. However, extended-term storage conditions will prolong the life of all films, independent of
age, type or processing conditions. The storage protection provided by each level will differ in degree, as will
the cost of providing and maintaining the storage facility.
Immediate availability of space and cost often need to be considered when selecting storage conditions. It is
recognized that many facilities will not be able to obtain the low humidity and low temperature levels specified
in this International Standard because of energy considerations, climate conditions or building construction.
Such deviation from the specified conditions will reduce the degree of protection offered, and in such cases
maintaining a humidity and temperature as low as possible will still provide some benefits.
This International Standard is not designed to provide protection against natural or man-made catastrophes,
with the exception of fire and associated hazards, which are sufficiently common to warrant inclusion of
protection measures.
In addition to the recommendations in this International Standard, good storage practices consider filing
enclosures. These are covered in ISO 18902 and ISO 18934.

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INTERNATIONAL STANDARD ISO 18911:2010(E)

Imaging materials — Processed safety photographic films —
Storage practices
1 Scope
This International Standard provides recommendations concerning the storage conditions, storage facilities,
handling and inspection for all processed safety photographic films in roll, strip, aperture-card or sheet format,
regardless of size.
This International Standard is applicable to extended-term and medium-term storage of photographic film.
This International Standard is applicable to photographic film records intended as storage copies, which are
not in frequent use. It does not apply to “work” or “use” copies (see Annex A).
This International Standard, while intended for materials that are properly processed, is also of considerable
value in prolonging the useful life of photographic film whose processing conditions are unknown, or which
has been toned or retouched, or has markings with materials of uncertain or unknown stability.
This International Standard is applicable only to safety photographic film (see ISO 18906). Nitrate-base films
are not covered by this International Standard.
NOTE Nitrate-base films are hazardous (see Reference [8]). They require special storage considerations (see
Reference [4]), but the environmental conditions specified in this International Standard are applicable.
The storage of photographic prints and photographic plates requires different considerations. They are not
covered in this International Standard, but are described respectively in ISO 18920 and ISO 18918.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 18902, Imaging materials — Processed imaging materials — Albums, framing and storage materials
ISO 18906, Imaging materials — Photographic films — Specifications for safety film
ISO 18916, Imaging materials — Processed imaging materials — Photographic activity test for enclosure
materials
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
duplicate
reproduction of a master, retaining the same polarity and size
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ISO 18911:2010(E)
3.2
extended-term storage conditions
storage conditions suitable for the preservation of recorded information on the majority of freshly and properly
processed photographic films for 500 years
3.3
fire-protective storage
facility 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
3.4
life expectancy
LE
length of time that information is predicted to be acceptable in a system at 21 °C and 50 % RH
NOTE In the past, the term “archival” was used to define material that could be expected to preserve images forever,
so that such images could be retrieved without significant loss when properly stored. However, as no such material exists,
this is now a deprecated term and is no longer used in International Standards for imaging materials or in systems
specifications.
3.5
LE designation
rating for the life expectancy (3.4) of recording materials and associated retrieval systems
NOTE The number following the LE symbol is a prediction of the minimum life expectancy, in years, during which
information can be retrieved without significant loss when stored at 21 °C and 50 % RH, e.g. LE-100 indicates that
information can be retrieved after at least 100 years' storage.
3.6
macroenvironment
atmospheric conditions (temperature, relative humidity and pollutants) in a large area in which records are
kept
3.7
medium-term storage conditions
storage conditions suitable for the preservation of recorded information for a minimum of 10 years
3.8
microenvironment
atmospheric conditions (temperature, relative humidity and pollutants) inside a storage enclosure in which
records are kept
3.9
open enclosure
enclosure that is intended for physical protection against mechanical damage, but is neither light-tight nor
airtight
EXAMPLE Reels; cores; spools; cassettes; magazines; folders; envelopes; cartons; boxes; sleeves; transparency
mounts; aperture cards.
3.10
protective enclosure
impermeable sealed container used for protection from outside factors such as reactive gases and moisture,
including changes in relative humidity, and from light for certain kinds of products
EXAMPLE Taped cans; sealed envelopes.
NOTE Protective enclosures sometimes also need to be opaque.
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ISO 18911:2010(E)
3.11
safety photographic film
photographic film
safety film
film that meets the flammability specifications defined in ISO 18906
3.12
storage housing
physical structure supporting materials and their enclosures
NOTE Storage housing can consist of drawers, racks, shelves or cabinets.
4 Film enclosures
4.1 Requirements
All enclosures used for medium-term and extended-term storage shall meet the requirements of ISO 18902.
Safety photographic film shall comply with the flammability specifications defined in ISO 18906.
4.2 Film in roll format
4.2.1 Medium-term storage enclosures
Aerial film, microfilm, motion-picture film, and some portrait films are wound on reels or cores and stored in roll
form. The rolls shall all be wound tightly, but not under extreme tensions. A tension caused by 0,3 N of pull-out
force for a 35 mm film width is recommended. Rolls greater than 150 m in length shall be stored so that the
radius of the roll is in the horizontal position and the film is supported on its edges. Rolls less than 150 m in
length may also be stored with the radius of the roll in the vertical position, if the core itself is supported by a
horizontal spindle inserted into the cores so as to avoid pressure on the bottom of the roll. However, if such
rolls are on reels or spools which have flanges, a spindle is not required since the flanges support the weight
of the roll.
Motion-picture prints shall be wound with the emulsion surface on the inside of the roll, as this improves
subsequent projection performance (see Reference [9]).
Rolls of photographic film shall be stored in closed containers to provide protection against dirt and physical
damage, unless the film is protected by the storage housing (see Clause 5).
Colour, diazo and thermally processed silver films shall be stored in closed, opaque enclosures or be
otherwise protected from light exposure. Suitable enclosures are containers with telescoping, slip-type, or
threaded twist-on lids. The materials used shall meet the same requirements as those for cores and reels.
Closed enclosures are not necessarily airtight and may provide limited access to ambient air. Therefore, if
they are used, the humidity of the ambient air shall not exceed the recommended limits.
Protective enclosures made from impermeable materials shall be used, where needed, to maintain the
humidity limits of the film (see Clause 7), to protect against gaseous impurities in the atmosphere, or when
low-temperature storage is used without humidity control (see Annex C). Suitable enclosures are closed
containers with friction-type or threaded, twist-on lids having an incorporated seal. Rubber gaskets shall not
be used. Cans within heat-sealed foil bags also provide protection from high humidity.
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ISO 18911:2010(E)
Metal containers provide the best protection against gases from the environment. However, they may corrode
1)
from acidic fumes from within the container unless they are protected with an overcoat. Alternative materials
are polystyrene, polyethylene and polypropylene.
4.2.2 Extended-term storage enclosures
For extended-term storage, the requirements of 4.2.1 shall be met. The materials used for reels, cores and
containers shall meet the requirements of ISO 18902 and ISO 18916. Rubber bands shall not be used for
confining film on reels or cores. If paper bands are used, the paper shall meet, as a minimum requirement, the
specifications described in ISO 18902 and ISO 18916. Films on reels may be confined by tucking the film end
between the roll and the flange. Pressure-sensitive tape, if needed for the enclosure, shall be free from
peroxide and pass the photographic activity test specified in ISO 18916. Pressure-sensitive tape shall not be
used in contact with the film.
Films may have possible interactions with other films that are of a different generic type (for example, diazo
and silver-gelatine), as well as with magnetic tapes and optical discs. Films of a different generic type shall not
be wound in the same rolls or stored in the same enclosures. Closed containers are required, unless the
photographic film is protected from dirt and damage by the storage housing (see Clause 5).
4.3 Film in sheet and slide format
4.3.1 Medium-term storage enclosures
Film in sheet form may be stored in envelopes of paper or plastic foil, folding cartons, boxes, file folders,
aperture cards, or film strip jackets. Photographic slides may be stored in cardboard, metal or plastic boxes.
Colour, diazo and thermally-processed silver films shall be stored in opaque envelopes or folders, or
otherwise protected from light exposure. Films should not be stacked, as this could cause excessive pressure
on the lowermost sheets. When in direct contact with the surface of the photographic film, the paper or plastic
material used for envelopes, sleeves, jackets, folders, boxes and cartons shall meet, as a minimum
requirement, the specifications described in ISO 18902 and ISO 18916.
Suitable plastic enclosure materials are uncoated polyester (polyethylene terephthalate), polystyrene,
polyethylene and polypropylene. Glassine envelopes and chlorinated, nitrated or highly plasticized sheeting
shall be avoided. Specifically, cellulose nitrate and polyvinyl chloride are not acceptable.
Protective enclosures shall be used, where needed, to maintain humidity within the limits recommended for
the specific film type (see Clause 7), to protect against gaseous impurities in the atmosphere, or when low-
temperature storage is used without humidity control. Heat-sealable envelopes, consisting of aluminium foil
extrusion coated with clear polyethylene on the inside and laminated to a suitable paper sheet on the outside,
have been successfully used as sealed enclosures. Precautions should be taken in handling these envelopes,
so that they are not punctured. To provide greater protection against pinholes, a double bagging technique is
recommended.
The adhesive used for seams and joints shall also meet the requirements of ISO 18902 and ISO 18916. The
filing enclosure shall be constructed so that any seam or joint will be at the edge of the enclosure and not in
contact with the image layer.
Any film that is actively releasing acidic fumes shall be stored in plastic or acid-neutralizing envelopes.
4.3.2 Extended-term storage enclosures
For extended-term storage, the requirements of 4.3.1 shall be met except that film shall not be stored in
cardboard enclosures.

1) Some vesicular films give off acidic fumes that may interact with silver, diazo or dye-gelatine-type films. Decomposing
acetate-base films release acetic acid, which further catalyses base degradation.
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ISO 18911:2010(E)
Photographic-quality gelatine, modified and photographically inert starch, some acrylic and polyvinyl acetate
adhesives and methyl cellulose are suitable for use with paper storage enclosures. Pressure-sensitive
(permanently tacky) adhesives shall meet the specifications of ISO 18902 and ISO 18916.
Films may have possible interactions with other films that are of a different generic type (for example, diazo
and silver-gelatine), as well as with magnetic tapes and optical discs. Films of different generic types shall not
be interfiled or be in physical contact.
5 Storage housings
Photographic film should be stored in closable housings, such as drawers or cabinets, or on shelves and
racks enclosed by tightly fitting doors in order to provide protection from dust and dirt. Alternatively, open
shelves and racks may be used if the film is in closed containers. The storage housing materials shall be non-
corrosive as described in ISO 18902. They shall also be non-combustible and chemically inert. Wood,
pressed-board, particle-board, plywood and other such materials shall be avoided due to their combustible
nature and the possibility of producing active deteriorating agents as they age.
The finish on storage housing materials shall be durable and should not contain substances that can have a
deleterious effect on stored photographic film. Adverse effects may be produced by finishes containing
chlorinated or highly plasticized resins, or by solvents off-gassing from freshly applied finishes. Paints used on
cabinets may give off peroxides, solvents and other contaminants for up to three months after being applied.
Metal housing materials that have been powder coated (a solvent-free finish process in which electrostatically
applied resin particles are fused by heat) or cabinets made from stainless steel or anodized aluminium are
recommended.
When air-conditioned individually, storage housings shall be arranged to permit interior circulation of air to all
shelves and drawers holding film containers so as to provide uniform humidity conditions. Storage housings,
located in rooms conditioned in accordance with 7.1 shall be provided with ventilation openings that permit
access of air to the interior. Such openings shall not interfere with the requirements for fire-protective storage
or water protection.
Films and other materials that release acidic fumes, magnetic tapes and optical discs shall not be stored in the
same storage housing as other photographic products.
6 Storage rooms
6.1 Medium-term storage rooms
Rooms and areas used for film storage should be located in the same area as rooms containing provisions for
inspection and viewing of the film. Good housekeeping is essential. Walls and enclosed air-conditioned
spaces shall be designed to prevent condensation of moisture on interior surfaces and within walls, especially
during periods of low exterior temperatures when the walls can be cooled below the dew-point of the air.
Provisions shall be made against damage of film by water from floods, leaks, sprinklers and from the steam
released from
...