ISO 15554:1998

INTERNATIONAL IS0
STANDARD 15554
First edition
1998-12-15
Practice for dosimetry in gamma irradiation
facilities for food processing
Pra tique de la dosimhtrie dans /es installations de traitement des produits
alimentaires par irradiation gamma
Reference number
IS0 15554: 1998(E)

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IS0 15554: 1998(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-qovernmental, 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 15554 was prepared by the American Society for Testing and Materials (ASTM)
Subcommittee E1O.O1 (as E 1204-93) and was adopted, under a special “fast-track procedure ”, by Technical
Committee ISOTTC 85, Nuclear energy, in parallel with its approval by the IS0 member bodies.
A new lSO/TC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review the
voting comments from the IS0 ‘Fast-track procedure” and to maintain these standards. The USA holds the
convenership of this working group.
International Standard IS0 15554 is one of 20 standards developed and published by ASTM. The 20 fast-tracked
standards and their associated ASTM designations are listed below:
IS0 Designation ASTM Designation Title
15554 E 1204-93 Practice for dosimetty in gamma irradiation facilities for food
processing
15555 E 1205-93 Practice for use of a ceric-cerous sulfate dosimetty system
15556 E 1261-94 Guide for selection and calibration of dosimetry systems for
radiation processing
15557 E 1275-93 Practice for use of a radiochromic film dosimetty system
15558 E 1276-96 Practice for use of a polymethylmethacrylate dosimetry system
15559 E 1310-94 Practice for use of a radiochromic optical waveguide dosimetry
sys tern
E 1400-95a Practice for characterization and performance of a high-dose
15560
radiation dosimetry calibration labora tory
E 1401-96
15561 Practice for use of a dichromate dosimetry system
0 IS0 1998
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic
or mechanical, including photocopying and microfilm, without permission in writing from the publisher.
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Printed in Switzerland
ii

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@ IS0 IS0 15554: 1998(E)
15562 E1431-91 Practice for dosimetry in electron and bremsstrahlung irradiation
facilities for food processing
E 1538-93 Practice for use of the ethanol-chlorobenzene dosimetry system
15563
E 1539-93 Guide for use of radiation-sensitive indicators
15564
15565 E 1540-93 Practice for use of a radiochromic liquid dosimetry system
Practice for use of the alanine-EPR dosimetry system
15566 E 1607-94
15567 E 1608-94 Practice for dosimetry in an X-ray (bremsstrahlung) facility for
radiation processing
E 1631-96 Practice for use of calorimetric dosimetry systems for electron
15568
beam dose meas
urements and dosimeter calibrations
Practice for dosimetry in an electron-beam facility for radiation
15569 E 1649-94
processing at energies between 300 keV and 25 MeV
Practice for use of cellulose dosimetry system
15570 E 1650-94 acetate
15571 E 1702-95 Practice for dosimetry in a gamma irra dia tion facility for radiation
processing
15572 E 1707-95 Guide for es tima ting uncertainties in dosimetry for radiation
processing
15573 E 1818-96 Practice for dosimetry in an electron-beam facility for radiation
processing at energies between 80 keV and 300 keV
I
. . .
111

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0 IS0 IS0 15554:1998(E)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
Designation: E 1204 - 93
1916 Race St. Philadelphia, Pa 19103
4Jb
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
If not listed in the current combined index, will appear in the next edition.
Standard Practice for
Dosimetry in Gamma irradiation Facilities for Food
Processing1
This standard is issued under the fixed designation E 1204; the numlxr immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (6) indicates an editorial change since the last revision or reapproval.
1. Scope Dose in Radiation-Hardness Testing of Electronic
Devices2
1.1 This practice outlines dosimetric procedures to be
925 Practice for the Periodic Calibration of Narrow
followed in irradiator characterization, process qualification,
Band-Pass Spectrophotometers3
and routine processing of food with ionizing radiation from
958 Practice for Measuring Practical Spectral Band-
isotopic gamma sources to ensure that all product has been
width of Ultraviolet-Visible Spectrophotometers3
treated within a predetermined range of absorbed dose.
1026 Practice for Using the Fricke Reference Standard
Other procedures related to irradiator characterization, pro-
Dosimetry System2
cess qualification, and routine processing that may influence
1205 Practice for Use of a Ceric-Cerous Sulfate
absorbed dose in the product are also discussed. Information
Dosimetry System2
about effective or regulatory dose limits for food products is
126 1 Guide for Selection and Application of Dosimetry
not within the scope of this practice (see Guides F 1355 and
F 1356). Systems for Radiation Processing of Food2
1275 Practice for Use of a Radiochromic Film
NOTE I-Dosimetry is only one component of a total quality
Dosimetry System2
assurance program for adherence to good manufacturing practices used
1276 Practice for Use of a Polymethylmethacrylate
in the production of safe and wholesome food.
Dosimetry System2
NOTE 2-Practice E 143 1 describes dosimetric procedures for elec-
tron beam and bremsstrahlung (X-ray) irradiation facilities for food
13 10 Practice for Use of a Radiochromic Optical
processing.
Waveguide Dosimetry System2
1400 Practice for Characterization and Performance of a
1.2 For guidance in the selection, calibration, and use of
High-Dose Gamma-Radiation Dosimetry Calibration
specific dosimeters, and interpretation of absorbed dose in
Laboratory2
the product from dosimetry measurements, see Guide
E 140 1 Practice for Use of a Dichromate Dosimetry
E 126 1; Practices E 666, E 668, E 1026, E 1205, E 1275,
System2 ’
E 1276, E 13 10, and E 1401. For discussion of radiation
E
143 1 Practice for Dosimetry in Electron Beam and
dosimetry for gamma rays and X-rays see ICRU Report 14,
Bremsstrahlung Irradiation Facilities for Food
1.3 This standard does not purport to address all of the
Processing2
safety prob(ems, tf any, associated with its use. It is the
E 1538 Practice for Use of an Ethanol-Chlorobenzene
responsibility of the user of this standard to establish appro-
Dosimetry System2
priate safety and health practices and determine the applica-
E 1539 Guide for the Use of Radiation-Sensitive
bility of regulatory limitations prior to use.
Indicators2
E 1540 Practice for the Use of a Radiochromic Liquid
2. Referenced Documents
Dosimetry System2
2.1 ASTM Standards: F
1355 Guide for the Irradiation of Fresh Fruits for Insect
E 170 Terminology Relating to Radiation Measurements
Disinfestation as a Quarantine Treatment4
and Dosimetry2
F 1356 Guide for the Irradiation of Fresh and Frozen Red
E 275 Practice for Describing and Measuring Performance
Meats and Poultry (to Control Pathogens)4
of Ultraviolet, Visible, and Near Infrared Spectro-
2.2 International Commission on Radiation Units and
photometers3
Measurements (ICR V ’) Reports:
E 666 Practice for Calculating Absorbed Dose from
ICRU Report 14-Radiation Dosimetry: X-Rays and
Gamma or X Radiation2
Gamma Rays with Maximum Photon Energies Between
E 668 Practice for Application of Thermoluminescence-
0.6 and 50 MeVs
Dosimetry (TLD) Systems for Determining Absorbed
ICRU Report 33-Radiation Quantities and Units5
2.3 Codex Alimentarius Commission Reports:
CAC Vol XV (1984): Codex General Standard for Irradi-
i This practice is under the jurisdiction of ASTM Committee E-10 on Nuclear
ated Foods and Recommended International Code of
Technology and Applications and is the direct responsibility of Subcommittee
E1O.O 1 on Dosimetry for Radiation Processing.
Current edition approved April 15, 1993. Published June 1993. Originally
published as E 1204 - 87, Last previous edition E 1204 - 87.
4 Annual Book of ASTM Standards, Vol 15.07.
2 Annual Book o/ASTM Standards, Vol 12.02.
s Available from the International Commission on Radiation Units and
3 Annual Book oJASTM Standards, Vol 14.0 1,
Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.

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IS0 15554:1998(E) 0 IS0
Practice for the Operation of Radiation Facilities Used pare absorbed-dose rates in radiation environments and
for the Treatment of Foods6 check the calibration of routine dosimeters. _
4. Significance and Use
3. Terminology
4.1 Food products may be treated with ionizing radiation,
Other terms used in this practice, in
3. I Definitions-
6oCo or 13YJs sources, for
such as gamma rays from
addition to those in 3.1.1 and 3.1.2, are defined in Termi-
numerous purposes, including parasite and pathogen con-
nology E 170 and in ICRU Report 33.
trol, insect disinfestation, growth and maturation inhibition,
3.1.1 absorbed dose, D-quotient of d(d by dm, where i(e)
and shelf-life extension. Food irradiation specifications usu-
is the mean energy imparted by ionizing radiation to matter
ally include a pair of absorbed-dose limits. For a given
of mass dm (see ICRU Report 33).
application, one or both of these values may be prescribed by
D = d(e)/dm
regulations based on available scientific data. Therefore, it is
The special name for the unit of absorbed dose is the gray
necessary to determine the capability of an irradiation
l
.
GYI
facility to process within these absorbeddose limits prior to
the irradiation of the food product. Once this capability is
1 Gy = I Jekg-’
established, it is necessary to monitor and record the
Formerly, the special unit for absorbed dose was the rad:
absorbed dose during each production run to verify compli-
1O-2 Jekg-’ = 1O-2 Gy
1 rad =
ance with the process specifications within a predetermined
level of confidence.
3.1.2 absorbed-dose mapping-measurement of the ab
sorbed-dose distribution in an irradiation unit through the
NOTE 3-The Codex Aliment&us Commissioa (I)? ws the term
use of dosimeters placed at specified locations within the
‘“overall average absorbed dose” indiscussing broad concepts such as the
irradiation unit. wholesomeness of foods bdiated to an overalI average absorbed dose
of less than 10 kGy. The overall average dose should not, however, be
3.2 Descriptions of Terms Specljic to This Standard:
used in place of minimum or maximum absorbed doses for specific
3.2.1 compensating dummvonsists of material that
applications. The CAC confirms this in the following statement from
matches the density and gamma attenuation characteristics
CAC/RCP 194979, Annex A: “(T)he design of the facility and the
of the actual product to the extent required to meet
operational parameters have to take into account minimum and
prescribed minimum or maximum absorbed doses. It is used
maximum dose values required by the process.”
during routine production runs within a partially filled
4.2 Some food products are processed in the chilled or ,
irradiation unit or at the beginning and end of a production
frozen state. Therefore, it is necessary to confirm that the
run to compensate for the absence of product. See also
dosimeters used for routine monitoring are useable at low
simulated product.
temperature and that the dosimeter temperature during
3.2.2 irradiation time-total time during which an irradi-
irradiation is sufFiciently stable to allow correction for
ation unit is exposed to radiation.
temperature effects on the dosimeter response.
3.2.3 irradiation unit-one or more containers of
4.3 For more detailed discussions of radiation processing,
product, collectively transported through the irradiator as a
see Guides F 1355 and F 1356 and Refs l-10.
whole, for example, box, tote, pallet, or carrier. This term is
not relevant to bulk-flow processing.
5. Radiation Source Characteristics
3.2.4 primary standard dosimeter-a dosimeter that has
5.1 The radiation source used in a facility considered in
the highest metrological quality in the field of radiation
this practice consists of sealed linear elements (rods or
dosimetry and is recognized as such on a national or
“‘pencils ”) of 6oCo or r37C~ arranged in one or more planar or
international basis.
cylindrical arrays.
3.2.5 production run-
a series of irradiation units con-
5.2 Cobalt-60 emits photons with energies of approxi-
taining the same food product irradiated sequentially to
mately 1.17 and 1.33 MeV in equal proportions. Cesium-137
nominally the same absorbed dose.
produces photons with energies of approximately 0.662 1MeV
3.2.6 reference standard dosimeter-a dosimeter, gener-
(11)
ally of the highest metrological quality available at a facility,
5.3 The half-lives for G°Co and 137Cs are approximately
that is traceable to national primary standards.
5.27 years and 30.2 years, respectively (11).
3.2.7 routine dosimeter-a dosimeter calibrated against a
primary, reference, or transfer standard dosimeter and used
6. Types of Facilities
routinely to make dosimetry measurements.
6.1 Food processing facilities may be categorized by
3.2.8 simulated product-consists of material that closely
irradiator type (for example, container or bulk flow), con-
matches the density and gamma attenuation characteristics
veyor system (for example, shuffle-dwell or continuous), and
of the foods of interest. It is used as a substitute for the actual
operating mode (for example, batch or continuous). Food
product during irradiator characterization.
products may be moved to the location in the facility where
3.2.9 transfer standard dosimeter-a dosimeter prepared
the irradiation will take place, either while the source is
in a stable and rugged form, used by a nationally recognized
shielded (batch operation) or while the source is exposed
standards calibration laboratory as an intermediary to com-
(continuous operation). Food products may be transported
6 Available from the Joint FAO/WHO Food Standards Program, Joint 0ff~~,
Food and Agriculture Organization of the United Nations, Via Della Terme de
7 The boldface numbers in parentheses refer to the list of references at the end
Caracalla, 00 100 Rome, Italy.
of this practice.
2
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@ IS0 IS0 15554: 1998(E)
past the source at a uniform controlled speed (continuous 8, Installation Qualification
conveyance), or may instead undergo a series of discrete
8.1 Equipment Documentation-Establish and document
controlled movements separated by controlled time periods
an irradiator qualification program to demonstrate that the
(shuffle-dwell). For irradiators with rectangular source ar-
irradiator, operating within specified limits, will consistently
rays, the irradiation unit generally makes one or more passes
produce an absorbed-dose distribution in a given product to
on each side of the source. Irradiation units may move past a
predetermined specification. Documentation shall include
rectangular source array in a configuration in which the
descriptions of instrumentation and equipment for ensuring
source either completely overlaps the irradiation unit or the
the reproducibility, within specified limits, of the source-
irradiation unit overlaps the source. In the latter configura-
to-product geometry and of the time the product spends at
tion, the irradiation unit is moved past the source at one or
different locations in the irradiation zone (12).
more different levels. In bulk-flow irradiators, products such
8.2 Equipment Testing-Test all processing equipment
as grain or flour flow in loose form past the source.
and instrumentation that may influence absorbed dose in
6.2 Because of mechanical speed limitations, various
order to verify satisfactory operation of the irradiator within
techniques are used to reduce the absorbed-dose rates for low
the design specifications.
absorbed-dose applications, These techniques include using
8.3 Equipment Calibration-Implement a documented
only a portion of the source, using attenuators, and irradi-
calibration program to assure that all equipment and instru-
ating at greater distances from the source.
mentation that may influence absorbed dose are calibrated
6.3 The details of a particular irradiator design affect the
within the specified limits.
delivery of absorbed dose to a product. They should,
8.4 Irradiator Characterization-Determine the overall
therefore, be considered when performing the absorbed-dose
performance of the irradiator in delivering absorbed dose to
measurements required in Sections 8, 9, and 10.
a product prior to routine processing.
8.4.1 The absorbed dose received by any portion of an
7. Dosimetry Systems (see Guide E 126 1, Practices E 1026, irradiated product depends on facility parameters such as the
E 1205, E 1275, E 1276, E 1310, E 1401, E 1538, and activity and geometry of the source, and on processing
E 1540) parameters such as the source-to-product distance and geom-
etry, the irradiation time, the product composition and
7.1 Dosimeter Classes and Applications:
density, and the product geometry.
7.1.1 Reference or Transfer Standard Dosimeters are used
8 ‘4.2 The absorbed-dose rate and absorbed-dose distribu-
to calibrate radiation fields (environments) and dosimeters
tion in the product will change during movement of the
employed in routine radiation processing. Reference or
irradiation unit. Therefore, a direct scaling from one ab
transfer dosimeters may also be used for the same purposes
sorbed dose to another on the basis of irradiation time may
as routine dosimeters (7.1.2). Reference and transfer stan-
not be valid and this effect should be considered during
dard dosimeters are traceable to national standards.
process qualification (see Section 9).
7.1.2 Routine Dosimeters are used for monitoring and for
8.4.3 To ensure that product near the source is processed
quality assurance in food irradiation processing. They are
within specifications, changes in the absorbed dose caused by
calibrated against primary, reference, or transfer standard
movement of the source to and from the irradiation position
dosimeters.
should be considered and quantified.
7.2 Operational and technical criteria for the selection of a
8.4.4 The irradiator characterization process includes
dosimetry system are given in Guide E 126 1.
mapping the absorbed-dose distributions in simulated or
7.3 Calibration of Dosimetry Systems:
actual irradiation units. Theoretical calculations of absorbed-
7.3.1 Prior to use, a routine dosimetry system shall be
dose rates and absorbed-dose distributions at various loca-
calibrated in accordance with a documented procedure that
tions within the irradiation unit may be used to define the
specifies details of the calibra.tion process and quality assur-
number and placement of dosimeters needed for the map-
ance requirements. Also, this calibration procedure shall be
ping procedure. Dosimetry data from previously character-
repeated at regular intervals to ensure that the accuracy of
ized irradiat
...