ISO 10602:1993
(Main)Photography — Processed silver-gelatin type black-and-white film — Specifications for stability
Photography — Processed silver-gelatin type black-and-white film — Specifications for stability
Photographie — Film de type gélatino-argentique noir et blanc traité — Spécifications pour la stabilité
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I N T E R NAT I O NA L IS0
STANDARD
10602
First edition
1993-03-01
Photography - Processed silver-gelatin
type black-and-white film - Specifications
for stability
Photographie - Film de type gélatino-argentique noir et blanc traité -
Spécifications pour la stabilité
Reference number
IS0 10602:1993(E)
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IS0 10602:1993(E)
Contents
Page
1 Scope . 1
2 Normative references . 1
3 Definitions . 1
4 Requirements for the film base . 2
5 Requirements for the processed film . 2
5.1 Safety film . 2
5.2 Amount of free acid . 2
5.3 Tensile properties and tensile properties loss . 2
6 Requirements for the emulsion and backing layers of processed
film . 3
6.1 Layer adhesion . 3
6.2 Emulsion flow . 3
6.3 Blocking . 3
6.4 Thiosulfate concentration . 3
6.5 Residual silver compounds . 3
7 Image stability . 4
7.1 Radiographic films . 4
Microfilms . 4
7.2
7.3 Other films . 4
8 Test methods . 4
8.1 Identification of film base . 4
8.2 Accelerated ageing conditions . 4
8.3 Determination of the amount of free acid . 5
8.4 Tensile property test for processed films . 5
8.5 Tape-stripping adhesion test . 6
(6 IS0 1993
All riahts reserved . No Dart of this aublication mav be rewoduced or utilized in anv form or
by any means. electronic or mechanical. including’photocopying and microfilm. without per-
mission in writing from the publisher .
International Organization for Standardization
Case Postale 56 CH-I21 1 Genève 20 Switzerland
Printed in Switzerland
II
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IS0 1 0602: 1 993 (E 1
8.6 Humidity-cycling adhesion test . 6
8.7 Emulsion flow test . 7
8.8 Blocking test . 7
8.9 Residual silver compound test . 7
8.10 Image stability test . 7
Annexes
A
Preparation of standard tetrabutylammonium hydroxide . 9
B
Washing and the effect of residual thiosulfate on the developed silver
image . 10
C Effect of residual silver compounds on the developed silver
image . 11
D Microscopic spots and blemishes . 12
E
Emulsion adhesion . 13
F
Accelerated image stability test for radiographic films . 14
G
Accelerated image stability test for microfilms . 16
H
Bibliography . 18
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IS0 10602:1993(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 10602 was prepared by Technical Committee
ISO/TC 42, Photography.
This first edition cancels and replaces both IS0 4331:1986, which covered
archival film on cellulose ester base, and IS0 4332:1986, which covered
archival film on poly(ethylene terephthalate) base. It constitutes a consoli-
dation and technical revision of these and, in addition, the scope has been
extended to include archival use of radiographic film and microfilm and
"medium-term" and "long-term" uses of all these films.
Annex A forms an integral part of this International Standard. Annexes B,
C, D, E, F, G and H are for information only.
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IS0 10602:1993(E)
Introduction
Since 1930, great advances have been made in the use of photographic
films for the preservation of records. The preservation of film records by
governments, banks, insurance companies, industry and other enterprises
has been stimulated by a recognition of the economies in storage space,
organization, accessibility, and ease of reproduction that results from the
use of film records.
During the early development period of the art of copying documents,
35 mm nitrate motion-picture film was sometimes used. This material is
highly flammable and deteriorates rapidly under unfavourable storage
conditions. Nitrate film is not suitable for film record use. The manufacture
of nitrate film declined after World War II and was discontinued in most
countries in the 1950's.
For many years the only safety films in commercial use were made on
some type of cellulose ester base such as cellulose acetate, cellulose
acetate propionate or cellulose acetate butyrate. The.useful life of safety
cellulose-ester-type films is somewhat conjectural, since actual experience
with commercial material extends back only to about 1908. However,
these materials show severe degradation when exposed to high tem-
peratures and particularly to high humidities [Il 141, Laboratory incubation
studies predict a useful life of several centuries[ll when stored under
recommended conditions.
A second type of polymer safety film base belonging to the polyester
class, known chemically as poly(ethylene terephthalate), was introduced
commercially in 1956. This material has a number of advantages over the
cellulose ester base such as greater strength, stiffness, tear resistance,
flexibility, dimensional stability, and other characteristics, which make it
121 [31. Actual experience with
superior for many photographic applications
polyester film is considerably shorter than with cellulose ester film al-
though this material has been used for over 35 years. However, core set
can create problems for some film types and adhesion was not completely
satisfactory on some of the early polyester products (see annex E). Prac-
tical experience gained to date and accelerated ageing tests indicate that
this film support is more stable than safety cellulose ester film base
il1 141.
More recent studies on the stability of silver-gelatin type films investigated
the effect of residual hypo on the image permanence of radiographic
films [51 and microfilms [61. This work suggested modifications to the re-
sidual hypo limits and a more quantitative image stability test than given
in IS0 4331:1986 and IS0 4332:1986. These changes are included in this
International Standard. Additional studies are underway on other film types
and future editions of this International Standard will include these when
stability data become available. Currently, radiographic films, microfilms
and "other" films are described. The scope of the "other" category should
narrow as additional categories are specifically defined. Three levels of
V
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IS0 10602:1993(E)
stability are specified - medium-term, long-term and archival, following
the definitions given in IS0 5466.
This International Standard is intended to eliminate possible hazards to
permanence attributable to the chemical or physical characteristics of the
processed film. Some of these characteristics are the responsibility of the
film manufacturer, some of the film processor and some are influenced
by both. However, specifying the chemical and physical characteristics of
the material does not, by itself, ensure satisfactory archival behaviour. It
is essential to provide proper storage temperattire and humidity and pro-
tection from the hazards of fire, water, fungus and certain atmospheric
pollutants. Storage conditions for archival films are specified in IS0 5466.
vi
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INTERNATIONAL STANDARD IS0 10602: 1993(E)
Photography - Processed silver-gelatin type
black-and-white film - Specifications for stability
are subject to revision, and parties to agreements
1 Scope
based on this International Standard are encouraged
to investigate the possibility of applying the most re-
1 .I This International Standard establishes the
cent editions of the standards indicated below.
specifications for photographic films intended for
Members of IEC and IS0 maintain registers of cur-
medium-term, long-term and archival records; specifi-
rently valid International Standards.
cally, safety cellulose ester-base and polyester-base
[poly(ethylene terephthalate)] films having silver-
IS0 5-21 991, Photography - Density measurements
gelatin emulsions processed to produce a black-and-
- Part 2: Geometric Conditions for transmission
white silver image by negative, or full reversal
density.
processing.
IS0 5-3: 1 984, Photography - Density measurements
1.2 This International Standard does not apply to
- Part 3: Spectral conditions.
films with colour images of any type, to silver images
that have been altered by treatments such as toning,
IS0 41 7:-*), Photography - Determination of re-
intensification or reduction, nor to films with a mag-
sidual thiosulfate and other related chemicals in proc-
netic recording track. It does not apply to films with
essed photographic materials - Methods using
silver images produced by dry or thermal processing
iodine-amylose, methylene blue and silver sulfide.
or by diffusion reversal or partial (halide) reversal
processing. It does not apply to films that have been
IS0 543: 1 990, Photography - Photographic films -
processed by a monobath or by those reversal pro-
Specifications for safety film.
cesses that combine a developer and fix into one
solution. It is not applicable to films where the silver
IS0 1 184: 1 983, Plastics - Determination of tensile
salts are removed by other than thiosulfate properties of films.
solutions [7].
IS0 5466: 1992, Photography - Processed safety
photographic films - Storage practices.
1.3 This International Standard does not apply to
films to which lacquers have been applied.
3 Definitions
1.4 This International Standard applies to films hav-
ing ultrasonic or dielectric (induction heated) splices. For the purposes of this International Standard, the
It does not cover films with splices made by means following definitions apply.
of adhesive tape or solvent type splices1).
3.1 archival storage conditions: Conditions suit-
able for the preservation of photographic film having
2 Normative references
permanent historical value.
The following standards contain provisions which,
NOTES
through reference in this text, constitute provisions
of this International Standard. At the time of publi- 1 Archival storage conditions will prolong the useful life
cation, the editions indicated were valid. All standards of both archival and non-archival films.
1) Solvent type splices are not recommended since they can retain traces of residual solvents containing peroxide which can
pose some risk of oxidative attack on the silver image.
2) To be published. (Revision of IS0 417:19771
1
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IS0 10602:1993(E)
2 The term "archival" as used in photography and defined
5 Requirements for the processed film
as in this International Standard is frequently being misap-
plied in related fields of imaging. ISO/TC 42 will therefore
5.1 Safety film
replace the term "archival storage" with "extended-term
storage" or specify a "life expectancy (LE)" classification in
The film shall meet the requirements specified in
future editions of its standards.
IS0 543.
3.2 archival film: Photographic film suitable for the
preservation of records having permanent value when
5.2 Amount of free acid
stored under archival storage conditions, providing the
original images are of suitable quality. Different specifications and test methods for deter-
mining the amount of free acid are given for polyester
base and cellulose ester base films. The polyester
3.3 long-term film: Photographic film suitable for
base shall not have an amount of free acid greater
the preservation of records for a minimum of 100
than the equivalent of 1 mI of 0,l moll1 sodium hy-
years when stored under archival storage conditions,
droxide solution per gram of film and the cellulose
providing the original images are of suitable quality.
ester base shall not have an amount of free acid
greater than the equivalent of 0,5 ml of 0,l moll1
3.4 medium-term storage conditions: Conditions
sodium hydroxide solution per gram of film. The
suitable for ensuring a minimum useful life of 1 O years
amount of free acid shall be measured in accordance
for photographic films.
8.3.
with
3.5 medium-term film: Photographic film suitable
The volume of 0,l moll1 sodium hydroxide equivalent
for the preservation of records for a minimum of 10
to the amount of free acid of the processed film shall
years when stored under medium-term storage con-
not increase by more than 0,5 ml over its original
ditions, providing the original images are of suitable
value after the accelerated ageing described in 8.2.
quality.
5.3 Tensile properties and tensile properties
3.6 non-curl backing layer: Layer usually made of
loss
gelatin, applied to the side of the film base opposite
that of the emulsion layer, for the purpose of pre-
The film samples shall be processed and dried under
venting curl. It is comparable to the emulsion layer in
the conditions used for the film records. Processed
thickness and is not removed in processing.
films shall be tested for tensile properties as de-
(Antihalation or other layers removed in processing
scribed in 8.4 and shall have a tensile strength and
are excluded from this definition.)
elongation at break as specified in table 1 for unheated
film. The loss in tensile properties after accelerated
3.7 safety photographic film: Film that meets the
8.2 shall not exceed the per-
ageing as described in
specifications with respect to ignition and burning
centage specified in table 1 for heated film.
time as defined in IS0 543.
Table 1 - Limits for tensile properties and
3.8 safety cellulose-ester base: Film base com-
tensile properties loss on ageing
posed mainly of cellulose esters of acetic, propionic,
i
or butyric acids, or mixtures thereof.
Base il^ Elongation
strength at at break
material
break %
3.9 safety poly(ethy1ene terephthalate) base:
Polyester film base composed mainly of a polymer of
ethylene glycol and terephthalic acid.
Minimum per- Cellulose MPa 1)
15
missible tensile ester
properties of
3.10 full reversal processing: Processing that in- 75
unheated film Polyester 140 MPa
cludes a final fix and wash after the second develop-
ment step.
Maximum per- Cellulose
15 % 30
missible loss in ester
tensile proper-
ties of heated
4 Requirements for the film base film compared I Polyester I 15 % I 30 I
with unheated
film
The base used for medium-term, long-term and ar-
I I I
chival record films shall be of a safety poly(ethy1ene
1) 1 MPa = 106 N/m*
terephthalate) or cellulose ester type and can be
identified by the method described in 8.1.
2
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IS0 10602:1993(E)
The analysis for thiosulfate shall be made on a film
6 Requirements for the emulsion and
sample from a clear area and shall be made within 2
backing layers of processed film
weeks of processing (see annex B).
The test method does not measure any change in the
6.1 Layer adhesion
sample between the time of processing and the time
of analysis but is used to judge the keeping of the film
following the time of the test.
6.1.1 Tape-stripping adhesion
The processed film shall not show any removal of the
emulsion layer or backing layer when tested as de-
mcentration
Table 2 - Limits for thiosulfate
scribed in 8.5.
Maximum
permissible
6.1.2 Humidity-cycling adhesion
concentration
Film
Film type
of
classification
thiosulfatel)
The emulsion layer or backing layer of the processed
film shall not show separation or cracking that would
am2
possibly impair its intended use, when tested as de-
scribed in 8.6 (see annex E).
Radiographic Medium-term 0,100
Long-term 0,050
Archival 0,020
6.2 Emulsion flow
The processed film shall not show any visual evidence
Long-term 0,030
Microfilms
of emulsion flow (caused by partial emulsion remelt-
0,014
Arc hiva I
ing) as a result of accelerated ageing of the processed
film. Emulsion flow shall be determined as described
in 8.7 when the accelerated ageing is performed as
Archival 0,0072)
Other: fine grain
described in 8.2.
Other: coarse grain Archival 0,020
6.3 Blocking
1) For radiographic and "other" films having photo-
graphic layers on both sides, or a non-curl backing layer,
Processed film shall show no evidence of blocking
values are for each side of the film. For microfilms, val-
(sticking), delamination or surface damage when
ues are for the complete film.
tested as described in 8.8. A slight sticking of the film
2) The limit for fine grain archival films is currently less
samples that does not result in physical damage or a
than for archival microfilms. This apparent anomaly is
change in the gloss of the surface is acceptable.
based on the results of a study of residual hypo that is
currently underway. The work on microfilm has been
completed but studies of other film types are not.
6.4 Thiosulfate concentration
Films shall be fixed in solutions containing either
sodium thiosulfate (hypo) or ammonium
thiosulfate [TI. Hypo-eliminating agents containing
oxidizing agents such as peroxides or hypochlorites
6.5 Residual silver compounds
st-,all not be used.3) After processing, the film shall not
contain a greater concentration of residual thiosulfate
The processed film shall not show more than a barely
calculated as thiosulfate ion S203- than that specified
in table2 when determined by the test methods de- perceptible tint when tested in accordance with 8.9
scribed in IS0 417.4) (see annex Cl.
3) Hypo-eliminating agents contain chemicals, usually strong oxidizing agents, which decompose thiosulfate (see annexes B
and D). These are to be distinguished from hypo clearing baths, which are high ionic strength salt solutions. These facilitate the
washing of thiosulfate from the film, but do not chemically alter the thiosulfate.
4) Three methods for measuring residual chemicals in film are described in21S0 41 7. All three methods are considered suf-
ficiently reliable to report thiosulfate concentrations at the level of 0,014 g/m . The methylene blue method is considered reli-
able for thiosulfate concentrations of 0,007 g/m2. The methylene blue and iodine amylose methods measure thiosulfate ion
only and must only be run within two weeks of processing. The silver sulfide densitometric test method measures polythionate
decomposition products and other residual chemicals in addition to thiosulfate. The method may be run more than two weeks
after processing. To determine thiosulfate levels accurately with this method, a calibration curve for the particular film is
necessary.
---------------------- Page: 9 ----------------------
IS0 10602:1993(E)
by the use of enzyme solution. All sublayers shall then
7 Image stability
be removed by scraping. A sample of the base ma-
terial shall then be prepared by scuffing the surface
The specifications and test methods for image stab-
with a suitable tool.
IS0
ility are different for the different product types.
visual diffuse density or Status A blue-density shall be
The general procedure is to move the scuffing device
measured on a densitometer which has spectral con-
back and forth over the sample manually while exert-
formance to IS0 5-3 and geometric conformance to
ing a very slight pressure. This removes the top layer
IS0 5-2. Processed film samples shall be incubated
of the base as a very fine dust, which is carefully
as described in 8.10.
brushed into a mortar. The sample shall be mixed with
about 100 times its mass of potassium bromide pre-
7.1 Radiographic films
viously ground to about 75 pm. A strip or pellet shall
be prepared as described in [8]. An infrared absorp-
An area of unexposed processed film shall be tested.
tion curve shall be obtained from the prepared pellet
The Status A blue-density change of the unexposed
by means of an infrared absorption spectro-
area shall be no greater than 0,05 density units after
photometer. By comparing the infrared absorption
incubation for medium-term, long-term and archival
curve for the unknown with curves for known
films.
polymers, the identity of the unknown can be estab-
lished W6)
7.2 Microfilms
Two areas on the processed film sample shall be
tested; one area of minimum density, the other having
8.2 Accelerated ageing conditions
a visual diffuse density of 1,2 f 0,l. The following
criteria shall apply to the different film categories.
Processed film shall be subjected to the accelerated
ageing conditions to meet the requirements for in-
7.2.1 Long-term film
crease in the amount of free acid, tensile properties
loss and emulsion flow.
The minimum density area shall have a visual diffuse
density of less than 0,4 after incubation. The differ-
The test specimens shall be conditioned to
ence in visual density between the two test areas
(23 f 1) "C and (50 f 2) % relative humidity for at
shall be at least 0,8 after incubation.
least 15 h. After conditioning, the specimens shall be
placed in a moisture-proof envelope and the envelope
7.2.2 Archival film
shall be heat-sealed." To prevent sticking between
adjacent specimens, it may be necessary to interleave
Neither the minimum nor the high density area shall
them with aluminium foil. A high ratio of film to air
change by more than 0,l visual diffuse density units
volume shall be ensured by squeezing out excess air
after incubation.
prior to heat sealing. A separate envelope shall be
used for each film sample. The envelopes shall be
7.3 Other films
heated in an oven for 72 h at (100 rt 2)
0
Samples of processed film containing representative An alternative method of incubatina the sDecimens in
image areas shall be tested. The film image shall a closed environment is by placing them in 25 mm
show no degradation after incubation that would im- borosilicate glass tubesW Each tube shall have two
pair the film for its intended use.5) flanged sections separated by a gasket to provide a
moisture seaP and shall be held together by a metal
clamp. Sufficient film specimens shall be used to
8 Test methods
provide a high ratio of film to air volume.
8.1 Identification of film base In subsequent subclauses, samples subjected to
these accelerated ageing conditions are designated
con-
All emulsion and backing layers shall be removed from "heated". Comparison samples kept at standard
ditions are designated "unheated".
a sample of the unknown film, either by scraping or
5) Work is currently underway to establish more quantitative tests for other film types.
6) It is difficult, although not impossible, to distinguish among cellulose acetate, cellulose acetate propionate and cellulose
acetate butyrate base by this method, but such separation is not necessary for the purpose of this International Standard.
7) A suitable moisture-proof envelope is a metal foil bag that is coated on the inside with polyethylene for heat-sealing.
8) Incubation is accomplished in a closed environment to prevent escape of any acid that is produced during incubation. Such
acid can catalyse further base degradation.
91 A suitable inert gasket can be made from poly(tetrafluoroethy1ene).
4
---------------------- Page: 10 ----------------------
IS0 10602:1993(E)
8.3 Determination of the amount of free acid A 30 mI blank, which has been heated for the same
length of time as the samples, shall be titrated. De-
tails of preparation of the standardized tetrabutyl-
8.3.1 Specimen preparation
A.
ammonium hydroxide are given in annex
Measurements shall be made on two unheated and
The cellulose ester solution shall be titrated with
two heated specimens of imaged film of mass ap-
0,l ml/l sodium hydroxide, using cresol purple as the
proximately 1 g to 2 g each. Weigh the specimens to
A blank titration shall also be made on the
indicator.
the nearest 0,Ol g. The films shall be heated in ac-
solvent mixture.
cordance with 8.2. All coatings shall be removed from
the film base by scraping. Each specimen shall be cut
8.3.4 Calculation
into small pieces and accurately weighed prior to dis-
solving in the appropriate solvents.
The amount of free acid, A, expressed in equivalent
millilitres of 0,l moi/i sodium hydroxide per gram of
8.3.2 Solution preparations
film base, is calculated as follows for each sample:
(Vs - VB~T
The polyester base and the cellulose ester base re-
A=
quire different solvents. 0,lm
Polyester samples shall be immersed in 30 ml of a
where
purified 70/30 (m/m) mixture of ocresol/chloroform.
V, is the volume of titrant used for the sam-
ple, in millilitres;
WARNING - Chloroform is harmful if inhaled.
Avoid breathing vapour, mist or gas. Use with
VB is the volume of titrant used for the blank,
adequate ventilation. If inhaled, move to fresh air.
in millilitres;
Contact should be avoided between chloroform
and eyes, skin or clothing. Obtain medical atten-
cT is the concentration of the titrant, in moles
tion immediately.
per litre;
o-Cresol is toxic if swallowed. Contact should be
m is the mass of the sample, in grams.
avoided between o-cresol and eyes, skin or cloth-
ing. Wash after handling. In case of contact, flush
Th titration shall be carried out in duplicate on sep-
eyes and skin thoroughly with water. Obtain
an dy prepared solutions. The average amount of
medical attention immediately.
free acid for the unheated and heated film samples
shall be calculated and reported separately.
The polyester support shall be dissolved by heating
at 90 OC to 95 OC for 30 min or until the sample has
8.4 Tensile property test for processed films
dissolved.lo) The dissolved samples shall be cooled to
room temperature.
8.4.1 Specimen preparation
Cellulose ester samples shall be immersed in ap-
proximately 80 mI of methylene chloride to which
Processed film already in 16 mm format may be
40 ml of denatured ethyl alcohol is then added slowly. tested in this width. In the case of perforated 16 mm
film, specimens shall be cut from between the per-
WARNING - Methylene chloride is harmful if
forations. Film in other sizes shall be cut into sections
inhaled. Avoid breathing vapour, mist or gas. Use
15 mm to 16 mm wide and at least 150 mm long us-
with adequate ventilation. If inhaled, move to
ing a sharp tool that does not nick the edges of the
fresh air. Contact should be avoided between
sample. Five specimens are required for the unheated
methylene chloride and eyes, skin or clothing.
film and five specimens for the heated film. The
Obtain medical attention immediately.
specimens to be heated and the control specimens
shall be cut alternately and contiguously from a single
piece of film. The thickness of each specimen shall
8.3.3 Titration
a suitable gauge to the nearest
be measured with
0,002 mm and the width to the nearest 0,l mm.
The polyester solution shall be titrated potentiometri-
cally with standardized 0,1 mol/l tetrabutylammonium
8.4.2 Accelerated ageing
hydroxide using an automatic recording titrimeter.”)
The electrode of the titrimeter shall have been pre-
conditioned for 24 h i
...
I NTE R NAT I O N AL
IS0
S TA N DA R D
10602
Second edition
1995-02-01
Photography - Processed silver-gelatin
type black-and-white film - Specifications
for stability
Photographie - Film de type gélatino-argentique noir et blanc traité -
Spécifications relatives à la stabilité
Reference number
IS0 10602:1995(E)
---------------------- Page: 1 ----------------------
IS0 10602: 1995(EI
Contents
Page
1 Scope . 1
2 Normative references . 1
3 Definitions . 2
4 Safety and hazards . 2
4.1 Hazard warnings . 2
4.2 Hazard information code system . 3
4.3 Safety precautions . 3
5 Requirements for film bases . 3
6 Requirements for processed film . 3
6.1 Safety film . 3
6.2 Amount of free acid . 3
6.3 Tensile properties and loss in tensile properties . 3
7 Requirements for the emulsion and backing layers of processed
film . 4
7.1 Layer adhesion . . 4
................................................ 4
7.2 Emulsion flow
7.3 Blocking . 4
7.4 Thiosulfate concentration . : . 4
7.5 Residual silver compounds . 5
8 Requirements for image stability . 5
8.1 Radiographic films . 5
8.2 Microfilms . 5
8.3 Other films . 5
9 Test methods . 5
9.1 Identification of film base . 5
O IS0 1995
All riahts reserved . Unless otherwise sDecified . no Dart of this Dublication mav be reDroduced
or uiized in any form or by any means. electronic or mechanical. including photocopying and
microfilm. without permission in writing from the publisher .
International Organization for Standardization
Case Postale 56 CH-1 21 1 Genève 20 Switzerland
Printed in Switzerland
Il
I
---------------------- Page: 2 ----------------------
Q IS0 IS0 10602:1995(E)
9.2 Accelerated ageing conditions . 6
9.3 Determination of the amount of free acid . 6
9.4 Tensile property test for processed film . 7
9.5 Tape-stripping adhesion test . 8
9.6 Humidity-cycling adhesion test .
9.7 Emulsion flow test .
9.8 Blocking test . 9
9.9 Residual silver compound test . 9
9.10 Image-stability test .
Annexes
A Preparation of standard solution of tetrabutylammonium
hydroxide . 11
B Washing and the effect of residual thiosulfate on the developed silver
image . . 12
C Effect of residual silver compounds on the developed silver
image . 13
............................................................
D Accelerated image-stability test for radiographic films . 14
E Accelerated image-stability test for microfilms . 15
F Accelerated image-stability test for aerial films . 16
G Bibliography . 17
...
III
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0 IS0
IS0 10602:1995(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 10602 was prepared by Technical Committee
lSO/TC 42, Photography.
This second edition cancels and replaces the first edition
(IS0 10602:1993), which has been technically revised.
Annex A forms an integral part of this International Standard. Annexes B,
C, D, E, F and G are for information only.
---------------------- Page: 4 ----------------------
0 IS0
IS0 10602:1995(E)
Introduction
Since 1930 great advances have been made in the use of photographic
films for the preservation of records. The preservation of film records by
governments, banks, insurance companies, industry and other enterprises
has been stimulated by a recognition of the economies in storage space,
organization, accessibility and ease of reproduction that result from the
use of film records.
During the early development period of the art of copying documents,
35 mm nitrate motion-picture film was sometimes used. This material is
highly flammable and is not a safety film as specified in IS0 543. Nitrate
film is not acceptable for any record film. The manufacture of nitrate
film declined after World War II and was discontinued in most countries
in the 1950's.
For many years the only safety films in commercial use were made on
some type of cellulose ester base, such as cellulose acetate, cellulose
acetate propionate or cellulose acetate butyrate. The useful life of safety
cellulose-ester-type films is somewhat conjectural, since actual experience
with commercial material extends back only to about 1908. However,
these materials show severe degradation when exposed to high tem-
peratures and particularly to high humidities. Laboratory incubation studies
predict a useful life of at least a century when stored under recommended
conditionsC~1, C211 Pl, 141.
A second type of polymer safety film base belonging to the polyester
class, known chemically as poly(ethy1ene terephthalate), was introduced
commercially in 1956. This material has a number of advantages over the
cellulose ester base such as greater strength, stiffness, tear resistance,
flexibility, dimensional stability and other characteristics, which make it
superior for many photographic applicationsC511 [SI. Actual experience with
polyester film is considerably less than with cellulose ester film although
this material has been used for over 35 years.
Practical experience to date and accelerated ageing tests indicate that this
film support is more stable than safety cellulose ester film base and is
expected to have a useful life of 500 yearsC1Ic C4l.
This second edition eliminates the film classifications of "archival",
"long-term" and "medium-term" and replaces them with the LE (life ex-
pectancy) rating. In addition, residual hypo limits and image-stability tests
are given for radiographic film, microfilm and all other films.
Studies on the stability of silver-gelatin-type films have investigated the
effect of residual hypo on the image permanence of radiographic filmsC71,
microfilmsC81 and aerial filmsC91. This work suggested modifications to the
residual hypo limits and a more quantitative image-stability test was in-
cluded in the first edition of IS0 10602. Residual hypo limits and image-
stability tests are now included for all film categories.
V
---------------------- Page: 5 ----------------------
IS0 10602:1995(E) 0 IS0
Former annex D, "Microsocopic spots and blemishes", and annex E,
"Emulsion adhesion", have been eliminated; an annex F, "Accelerated
image-stability test for aerial films", has been added.
This International Standard identifies certain hazards to permanence at-
tributable to the chemical or physical characteristics of processed film and
gives methods of evaluating them. Some of these characteristics are the
responsibility of the film manufacturer, some of the film processor, and
some are influenced by both. However, specifying the chemical and
physical characteristics of the material does not, by itself, ensure satis-
factory keeping behaviour. It is essential to provide proper storage tem-
perature and humidity, and protection from the hazards of fire, water,
fungus and certain atmospheric pollutants. It is important that films be
stored under the conditions specified in IS0 5466 and IS0 10214.
---------------------- Page: 6 ----------------------
IS0 10602:1995(E)
INTERNATIONAL STANDARD Q IS0
Photography - Processed silver-gelatin type
black-and-white film - Specifications for stability
1 Scope 2 Normative references
0 1.1 This International Standard establishes the
specifications for photographic films intended for the
The following standards contain provisions which,
storage of records.
through reference in this text, constitute provisions
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All standards
1.2 It applies specifically to films with a base of
are subject to revision, and parties to agreements
safety cellulose ester or polyester [poly(ethylene
based on this International Standard are encouraged
terephthalate)] having silver-gelatin emulsions, pro-
to investigate the possibility of applying the most re-
cessed to produce a black-and-white silver image by
cent editions of the standards indicated below.
negative or full-reversal processing. It applies to film
Members of IEC and IS0 maintain registers of cur-
processed by a monobath which includes thiosulfate
rently valid International Standards.
as the fixing agent followed by a conventional wash.
It also applies to silver films given a stabilizing treat-
IS0 5-1 :I 984, Photography - Density measurements
ment by partial or full conversion to silver sulfide, sil-
- Part 1: Terms, symbols and notations.
ver selenide or gold.
IS0 5-2:1991, Photography - Density measurements
1.3 This International Standard does not apply to
- Part 2: Geometric conditions for transmission
films with colour images of any type, nor to films with
density.
a magnetic recording track. It does not apply to films
0 with silver images produced by dry or thermal pro-
IS0 5-3:-2), Photography - Density measurements
cessing or by diffusion-reversal processing. It does
- Part 3: Spectral conditions.
not apply to films that have been processed by a
monobath using other than a thiosulfate-type fixing IS0 41 7:1993, Photography - Determination of re-
solution. It is not applicable to films where the silver
sidual thiosulfate and other related chemicals in pro-
salts are removed by means other than thiosulfate
cessed photographic materials - Methods using
solutionsCl~1.
iodine-amylose, methylene blue and silver sulfide.
IS0 543: 1990, Photography - Photographic films -
1.4 This International Standard does not apply to
Specifications for safety film.
films to which lacquers have been applied.
IS0 1 1 84: 1 983, Plastics - Determination of tensile
1.5 This International Standard applies to films
propeflies of films.
having ultrasonic or dielectric (induction heated)
splices. It does not cover films with splices made by
IS0 5466:1992, Photography - Processed safety
means of adhesive tape or solvent-type splices.’)
photographic films - Storage practices.
1) Solvent-type splices are suspect since they may retain traces of residual solvents containing peroxide which can pose some
risk of oxidative attack on the silver image.
2) To be published. (Revision of IS0 5-3:1984)
1
---------------------- Page: 7 ----------------------
0 IS0
IS0 10602:1995(E)
NOTE 4 Antihalation or other layers removed in process-
IS0 10214:1991, Photography - Processed photo-
ing are excluded from this definition.
graphic materials - Filing enclosures for storage.
3.9 safety photographic film: Photographic film
which passes the ignition time test and burning time
3 Definitions
test as specified in IS0 543.
For the purposes of this International Standard, the
3.10 safety cellulose-ester base: A film base com-
definitions given in IS0 5-1 and the following defi-
posed mainly of the cellulose esters of acetic,
nitions apply.
propionic or butyric acids, or mixtures thereof.
3.1 archival medium: A recording material that can
3.1 1 safety poly(ethy1ene terephthalate) base: A
be expected to retain information forever so that it
polyester film base composed mainly of a polymer of
can be retrieved without significant loss when prop-
ethylene glycol and terephthalic acid.
erly stored.
3.12 full-reversal processing: Processing that in-
NOTE 1 There is, however, no such material and it is not
cludes development, bleach, clear, re-exposure and
a term to be used in International Standards or system
second development, followed by fixing and washing.
specifications.
3.2 life expectancy (LE): The length of time that
4 Safety and hazards
information is predicted to be retrievable in a system
under extended-term storage conditions.
4.1 Hazard warnings
NOTE 2 However, the actual useful life of film is very
Some of the chemicals specified in the test pro-
dependent upon the existing storage conditions (see
cedures are caustic, toxic or otherwise hazardous.
IS0 5466 and IS0 10214).
Safe laboratory practice for the handling of chemicals
requires the use of safety glasses or goggles, rubber
3.3 LE designation: A rating for the "life
gloves and other protective apparel such as face
expectancy" of recording materials and associated
masks or aprons where appropriate. Specific danger
retrieval systems. The number following the LE sym-
notices are given in the text and footnotes for par-
bol is a prediction of the minimum life expectancy, in
ticularly dangerous materials, but normal precautions
years, for which information can be retrieved without
are required during the performance of any chemical
significant loss when stored under extendedaterm
procedureqat all times. The first time that a hazardous
storage conditions.
material is noted in the test procedure section, the
hazard will be indicated by the word "DANGER" fol-
For example, LE-100 indicates that information
NOTE 3
lowed by a symbol consisting of angle brackets
can be retrieved for at least 1 O0 years' storage.
"< >" containing a letter which designates the
specific hazard. A double bracket "<< >>" will be
3.4 extended-term storage conditions: Storage
used for particularly perilous situations. In subsequent
conditions suitable for the preservation of recorded
statements involving handling of these hazardous
information having permanent value.
materials, only the hazard symbol consisting of the
brackets and letter(s) will be displayed. Furthermore,
3.5 medium-term storage conditions: Storage
for a given material, the hazard symbol will be used
conditions suitable for the preservation of recorded
only once in a single paragraph.
information for a minimum of 10 years.
Detailed warnings for handling chemicals and their
3.6 film base: The plastic support for the emulsion
diluted solutions are beyond the scope of this Inter-
and backing layers.
national Standard.
3.7 emulsion layers(s1: The image or image-
Employers shall provide training and health and
forming layer(s1 of photographic films, papers and
safety information in conformance with legal re-
plates.
quirements.
3.8 noncurl backing layer: A layer, usually made The hazard symbol system used in this International
of gelatin, applied to the side of the film base opposite Standard is intended to provide information to the
that of the emulsion layer, for the purpose of pre- users and is not meant for compliance with any legal
venting curl. It is comparable to the emulsion layer in
requirements for labelling as these vary from country
thickness and is not removed in processing.
to country.
2
---------------------- Page: 8 ----------------------
Q IS0
IS0 10602:1995(E)
It is strongly recommended that anyone using
6 Requirements for processed film
these chemicals obtain from the manufacturer
pertinent information about the hazards, hand-
Films shall be stored under the conditions specified in
ling, use and disposal of these chemicals.
IS0 5466 and IS0 10214.
4.2 Hazard information code system
Harmful if inhaled. Avoid breathing dust,
vapour, mist or gas. Use only with ad-
6.1 Safety film
equate ventilation.
Harmful if contact occurs. Avoid contact
The film shall meet the requirements specified in
with eyes, skin or clothing. Wash
IS0 543.
thoroughly after handling .
Harmful if swallowed. Wash thoroughly
after handling. If swallowed, obtain medi-
cal attention immediately.
6.2 Amount of free acid
May be fatal if swallowed. If swallowed,
obtain medical attention immediately.
Different specifications and test methods are given
for polyester base and cellulose-ester base films. The
Will burn. Keep away from heat, sparks
polyester base shall not have an amount of free acid
and open flame. Use with adequate venti-
greater than the equivalent of 1,0 mI of 0,l mol/l
la t i O n3).
sodium hydroxide solution per gram of film, and the
cellulose-ester base shall not have an amount of free
Oxidizer. Contact with other material may
acid greater than the equivalent of 0,5 mI of
cause fire. Do not store near combustible
0,l mol/l sodium hydroxide solution per gram of film.
ma te ria Is.
The amount of free acidity shall be measured in ac-
cordance with 9.3.
4.3 Safety precautions
The volume of 0,l moll1 sodium hydroxide equivalent
All pipette operations shall be performed with a
to the amount of free acid of the processed film shall
pipette bulb or plunger pipette.
not increase by more than 0,5 ml/l over its original
value after the accelerated ageing described in 9.2.
Safety glasses shall be worn for all laboratory
work.
5 Requirements for film bases
The base used for record films, as specified in this
6.3 Tensile properties and loss in tensile
International Standard, shall be of a safety polyester
properties
[i.e. poly(ethy1ene terephthalate)] or a cellulose-ester
type, and can be identified by the method described
The film samples shall be processed and dried under
in 9.1.
the conditions used for the film records. Processed
films shall be tested for tensile properties as de-
Some films on a cellulose-ester-type base can have a
scribed in 9.4 and shall have a tensile stress and
maximum LE rating of 100. Some films on a polyester
elongation at break as specified in table 1 (unheated
base can have a maximum LE rating of 500.
film). The loss in tensile properties after accelerated
NOTE 5 These limitations are based on historical experi- ageing as described in 9.2 shall not exceed the per-
ences as discussed in the introduction.
centage specified in table 1 (heated film).
3) The flammable warning symbol < F > will not be used for quantities of common solvents under 1 litre.
3
---------------------- Page: 9 ----------------------
0 IS0
IS0 10602:1995(E)
7.2 Emulsion flow
Table 1 - Limits for tensile properties and loss
The processed film shall not show any visual evidence
in tensile properties on ageing
of emulsion flow (caused by partial emulsion remelt-
~~
ing) as a result of accelerated ageing of the processed
Tensile
Elongation
film. Emulsion flow shall be determined as described
Film type stress at
at break
in 9.7 when the accelerated ageing is performed as
break
described in 9.2.
Unheated film
7.3 Blocking
Minimum permissible
tensile properties:
Processed film shall show no evidence of blocking
Cellulose-ester base 80 MPal) 15 %
(sticking), delamination or surface damage when
Polyester base 140 MPa 75 %
tested as described in 9.8. A slight sticking of the film
Heated film
samples that does not result in physical damage or a
change in the gloss of the surface shall be acceptable.
Maximum permissible
loss in tensile properties
compared with unheated
7.4 Thiosulfate concentration
film:
Cellulose-ester base 15 % 30 % Films shall be fixed in solutions containing either a
sodium thiosulfate (hypo) or ammonium thiosul-
Polyester base 15 % 30 %
fateClo1. Hypo-eliminating agents containing oxidizing
1) 1 MPa = IO6 N/m2 agents such as peroxides or hypochlorites shall not
be used.
NOTE 6 Hypo-eliminating agent contains chemicals,
7 Requirements for the emulsion and
usually strong oxidizing agents, which decompose thiosul-
backing layers of processed film fate (see annexes B and DI. These are to be distinguished
from hypo-clearing baths, which are high ionic strength salt
solutions. These facilitate the washing of thiosulfate from
the film, but do not chemically alter the thiosulfate.
7.1 Layer adhesion
After processing, the film shall not contain a greater
7.1. Tape-stripping adhesion
concentration of residual thiosulfate calculated as
thiosulfate ions (S,O,* 7 than that specified in table 2
The xocessed film shall not show any removal of the
when determined by one of the test methods de-
emi sion layer or backing layer when tested as de-
scribed in IS0 4174’.
scribed in 9.5.
The analysis for thiosulfate shall be made on a film
*
sample from a clear area and shall be made within
7.1.2 Humidity-cycling adhesion
2 weeks after processing (see annex BI. The test
The emulsion layer or backing layer of the processed method does not measure any change in the sample
film shall not show separation or cracking that can between the time of processing and the time of
impair its intended use, when tested as described in analysis, but is used to judge the keeping of the film
9.6. following the time of the test.
4) Three methods for measuring residual thiosulfate based chemicals in film are described in IS0 417. All three methods are
0,014 g/m2 of S,O; -. The methylene blue
considered sufficiently reliable to report thiosulfate concentrations at the level of
method is considered reliable for thiosulfate concentrations of 0,007 g/m2. The methylene blue and iodine amylose methods
measure thiosulfate ions only. They must be run within 2 weeks of processing. The silver sulfide densitometric test method
measures polythionate decomposition products and other residual chemicals in addition to thiosulfate. The method may be run
more than 2 weeks after processing. To determine thiosulfate levels accurately with this method, a calibration curve for the
particular film is necessary.
---------------------- Page: 10 ----------------------
0 IS0 IS0 10602: 1995(E)
Table 2 - Limits for thiosulfate (SO;! '-1 concentration
I
Maximum permissible concentration
3)
of thiosulfate2)
Film classificationl)
Film type
LE-1 O 0,100
Radiographic films
LE-1 O0 0,050
LE-500 0,020
Microfilms LE-1 O0 0,030
0,014
LE-500
LE-1 O
Other films 0,100
LE-1 O0 0,050
LE-500 0,014
1) LE-500 film only applies to polyester base film.
2) Values are for each side of the film which has a photographic layer or a noncurl backing layer.
3) The concentration of thiosulfate is expressed in grams per square metre, which conforms to SI units.
O,OI O g/m2 = I pg/cm2
8.2.1 LE-100 film
7.5 Residual silver compounds
The area of minimum density shall have a visual dif-
The processed film shall not show more than a barely
fuse density of less than 0,4 after incubation. The
perceptible tint when tested in accordance with 9.9
difference in visual density between the two test
(see annex Cl.
areas shall be at least 0.8 after incubation.
8 Requirements for image stability
8.2.2 LE-500 film
The specifications and test methods for image stab-
Neither the minim u m-density nor the hig h-density
ility are different for the different product types. IS0
area shall change by more than $I 0,l in visual diffuse
visual diffuse density or status A blue density shall be
density units after incubation.
0 measured on a densitometer which has spectral con-
formance to IS0 5-3 and geometric conformance to
8.3 Other films
IS0 5-2. Processed film samples shall be incubated
as described in 9.10.
A minimum-density area and a 1,0 $I 0,l status A blue
density patch of processed film shall be tested.
Neither the minimum-density area nor the high-
8.1 Radiographic films
density patch shall change by more than f 0,l
status A blue density units after incubation. This re-
An area of unexposed processed film shall be tested.
quirement shall apply to LE-IO, LE-100 and LE-500
The status A blue density change of the unexposed
films.
area shall be no greater than 0,05 density units after
incubation. This requirement shall apply to LE-1 O,
LE-100 and LE-500 films.
9 Test methods
8.2 Microfilms 9.1 Identification of film base
An area of minimum density and another having a Remove all emulsion and backing layers from a
visual diffuse density of 1,2 f 0,l on the processed sample of unknown film, either by scraping or by the
film sample shall be tested. The criteria given in 8.2.1 use of enzyme solution. Then remove all sublayers by
and 8.2.2 shall apply to the different film categories. scraping. Prepare a sample of the base material by
5
---------------------- Page: 11 ----------------------
0 IS0
IS0 10602:1995(E)
NOTE 8 In the subsequent text, samples subjected to
scuffing the surface with a suitable tool such as a
these accelerated ageing conditions are designated "heated
razor blade. The general procedure is to move the
film". Comparison samples kept at room conditions are
scuffing device back and forth over the sample
designated "unheated film".
manually while exerting a very slight pressure. This
removes the top layer of the base as a very fine dust.
Carefully brush this into a mortar.
9.3 Determination of the amount of free acid
Mix the sample with about 100 times its mass of
9.3.1 Specimen preparation
potassium bromide, previously ground to about
75 pm. Prepare a strip or pellet as described in refer-
Measurements shall be made on two unheated and
ence [ll].
two heated specimens of imaged film that weigh ap-
proximately 1 g to 2 g each. Weigh the specimens to
Obtain an infrared absorption curve from the prepared
the nearest 0,Ol g. Heat the films in accordance with
pellet by means of an infrared absorption spec-
9.2. Remove all coatings from the film base by
trometer. By comparing the infrared absorption curve
scraping. Cut each specimen into small pieces and
for the unknown with curves for known polymers, the
accurately weigh it prior to dissolving it in the appro-
identity of the unknown can be established[121.
priate solvents.
NOTE 7 It is difficult, although not impossible, to dis-
tinguish between cellulose acetate, cellulose acetate
9.3.2 Solution preparation
propionate and cellulose acetate butryate bases by this
method, but such separation is not necessary for the pur-
The polyester base and the cellulose-ester base re-
poses of this International Standard.
quire different solvents.
Immerse the polyester specimens in 30 ml of a
70/30 (m/m) mixture of purified ocresol/chloroform
9.2 Accelerated ageing conditions
(DANGER: < B > < C > < S >).
Processed film shall be subjected to accelerated age-
WARNING - Chloroform is harmful if inhaled.
ing conditions to meet the requirements for increase
Avoid breathing vapour, mist or gas. Use with
in the amount of free acid, loss in tensile properties,
adequate ventilation. If inhaled, move to fresh air.
and emulsion flow.
Contact should be avoided between chloroform
and the eyes, skin or clothing. In case of contact,
at
The test specimens shall be conditioned
obtain medical attention immediately.
(23 f 1) OC and (50 f 2) % relative humidity for at
least 15 h. After conditioning, place the specimens in
o-Cresol is toxic if swallowed. Contact should be
a moisture-proof envelope and heat-seal the envel-
avoided between o-cresol and the eyes, skin or
opes). To prevent sticking between adjacent speci-
clothing. Wash after handling. In case of contact,
mens, it may be necessary to interleave them with
flush eyes and skin thoroughly with water. Obtain 0
aluminium foil. Ensure a high ratio of film to air vol-
medical attention immediately.
ume by squeezing out excess air prior to heat-sealing.
Use a separate envelope for each film sample. Double
Take
...
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