ASTM ISO/ASTM51702-13(2021)

Standard Practice for Dosimetry in a Gamma Facility for Radiation Processing

SIGNIFICANCE AND USE
4.1 Various products and materials routinely are irradiated at predetermined doses in gamma irradiation facilities to reduce their microbial population or to modify their characteristics. Dosimetry requirements may vary depending upon the irradiation application and end use of the product. Some examples of irradiation applications where dosimetry may be used are:  
4.1.1 Sterilization of medical devices,  
4.1.2 Treatment of food for the purpose of parasite and pathogen control, insect disinfestation, and shelf life extension,  
4.1.3 Disinfection of consumer products,  
4.1.4 Cross-linking or degradation of polymers and elastomers,  
4.1.5 Polymerization of monomers and grafting of monomers onto polymers,  
4.1.6 Enhancement of color in gemstones and other materials,  
4.1.7 Modification of characteristics of semiconductor devices, and  
4.1.8 Research on materials effects.
Note 3: Dosimetry is required for regulated irradiation processes such as sterilization of medical devices and the treatment of food. It may be less important for other industrial processes, for example, polymer modification, which can be evaluated by changes in the physical and chemical properties of the irradiated materials.  
4.2 An irradiation process usually requires a minimum absorbed dose to achieve the intended effect. There also may be a maximum absorbed dose that the product can tolerate and still meet its functional or regulatory specifications. Dosimetry is essential to the irradiation process since it is used to determine both of these limits and to confirm that the product is routinely irradiated within these limits.  
4.3 The absorbed-dose distribution within the product depends on the overall product dimensions and mass, irradiation geometry, and source activity distribution.  
4.4 Before an irradiation facility can be used, it must be qualified to determine its effectiveness in reproducibly delivering known, controllable absorbed doses. This involves testing the pro...
SCOPE
1.1 This practice outlines the installation qualification program for an irradiator and the dosimetric procedures to be followed during operational qualification, performance qualification, and routine processing in facilities that process products with ionizing radiation from radionuclide gamma sources to ensure that product has been treated within a predetermined range of absorbed dose. Other procedures related to operational qualification, performance qualification, and routine processing that may influence absorbed dose in the product are also discussed.
Note 1: Dosimetry is only one component of a total quality assurance program for adherence to good manufacturing practices used in radiation processing applications.
Note 2: ISO/ASTM Practices 51818 and 51649 describe dosimetric procedures for low and high enery electron beam facilities for radiation processing and ISO/ASTM Practice 51608 describes procedures for X-ray (bremsstrahlung) facilities for radiation processing.  
1.2 For the radiation sterilization of health care products, see ISO 11137-1. In those areas covered by ISO 11137-1, that standard takes precedence.  
1.3 This document is one of a set of standards that provides recommendations for properly implementing and utilizing dosimetry in radiation processing. It is intended to be read in conjunction with ASTM Practice E2628.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization...

General Information

• Status: Published
• Publication Date: 30-Sep-2021
• ICS: 17.240 - Radiation measurements
• Technical Committee: E61 - Radiation Processing
• Drafting Committee: E61.03 - Dosimetry Application

Relations

• Refers: ASTM E170-17 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Jun-2017
• Refers: ASTM E170-16a - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Oct-2016
• Refers: ASTM E170-16 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 15-Feb-2016
• Refers: ASTM E170-15a - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Sep-2015
• Refers: ASTM E170-15 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 15-Mar-2015
• Refers: ASTM E170-14a - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 15-Oct-2014
• Refers: ASTM E170-14 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Sep-2014
• Refers: ASTM E2303-11 - Standard Guide for Absorbed-Dose Mapping in Radiation Processing Facilities
• Effective Date: 01-Jul-2011
• Refers: ASTM E2303-11e1 - Standard Guide for Absorbed-Dose Mapping in Radiation Processing Facilities
• Effective Date: 01-Jul-2011
• Refers: ASTM E2232-10 - Standard Guide for Selection and Use of Mathematical Methods for Calculating Absorbed Dose in Radiation Processing Applications
• Effective Date: 01-Jul-2010
• Refers: ASTM E170-10 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Jun-2010
• Refers: ASTM E2628-09 - Standard Practice for Dosimetry for Radiation Processing
• Effective Date: 15-Aug-2009
• Refers: ASTM E170-09a - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 15-Aug-2009
• Refers: ASTM E170-09 - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 15-Jun-2009
• Refers: ASTM E170-08d - Standard Terminology Relating to Radiation Measurements and Dosimetry
• Effective Date: 01-Nov-2008

Overview

ASTM ISO/ASTM51702-13(2021): Standard Practice for Dosimetry in a Gamma Facility for Radiation Processing provides comprehensive guidance for implementing dosimetry in gamma irradiation facilities. Developed by ASTM and ISO, this international standard specifies procedures for the installation, operation, qualification, and routine control of dosimetry systems in facilities using radionuclide gamma sources, ensuring that products receive appropriate and verifiable absorbed radiation doses. The standard supports sectors where accurate measurement of absorbed dose is critical for product quality, safety, and regulatory compliance.

Key Topics

• Dosimetry Procedures: Outlines detailed dosimetry practices necessary during installation, operational qualification, performance qualification, and routine processing.
• Irradiator Qualification: Describes the steps required to qualify the irradiator and associated equipment, ensuring compliance with technical and safety specifications.
• Absorbed Dose Control: Emphasizes controlling the absorbed dose within predetermined minimum and maximum limits for different products and applications.
• Mapping and Monitoring: Covers absorbed-dose mapping, routine monitoring positions, and processes for products with varying densities or configurations.
• Process Parameters: Details how process variables such as conveyor speed, timer settings, and product placement affect dose delivery and require monitoring.
• Calibration and Quality Assurance: Specifies the need for regular calibration of dosimetry systems and integration with total quality management programs.
• Documentation Requirements: Stresses thorough documentation for equipment, procedures, calibration records, and process control.

Applications

The standard is crucial across multiple fields where gamma irradiation is employed, ensuring product safety and efficacy:

• Medical Device Sterilization: Ensures that medical devices are sterilized within defined dose ranges for safety and regulatory compliance.
• Food Treatment: Used for pathogen and parasite control in food, insect disinfestation, and shelf life extension, meeting global food safety standards.
• Product Disinfection: Applied to consumer goods to achieve disinfection goals and maintain public health standards.
• Polymer Processing: Supports cross-linking, degradation, and polymerization of polymers and elastomers, enabling desired material properties.
• Material Modification: Used in the enhancement of color in gemstones, modification of semiconductor devices, and scientific research on materials.
• Research: Provides a framework for measuring effects in experimental irradiation of various materials, supporting innovation and development.
• Regulated Processes: Dosimetry is mandatory for regulated processes such as sterilization of healthcare products and food irradiation, allowing compliance with national and international regulations.

By following the standard, gamma irradiation facilities can demonstrate that they deliver consistent, traceable, and verifiable absorbed doses, which is integral for customer assurance, certification, and regulatory approval.

Related Standards

ASTM ISO/ASTM51702-13(2021) is part of a suite of standards that collectively provide best practices for dosimetry in radiation processing:

• ISO/ASTM 51818: Dosimetry for low-energy electron beam facilities.
• ISO/ASTM 51649: Dosimetry for high-energy electron beam facilities.
• ISO/ASTM 51608: Dosimetry for X-ray (bremsstrahlung) facilities for radiation processing.
• ASTM E2628: Practice for Dosimetry in Radiation Processing, recommended as a companion document.
• ISO 11137-1: Sterilization of health care products – requirements for radiation-based processes (takes precedence for health care sterilization).
• ASTM E170: Terminology relating to radiation measurements and dosimetry.
• ISO/ASTM 51261: Calibration of routine dosimetry systems for radiation processing.
• ISO/ASTM 51539: Guide for use of radiation-sensitive indicators.

Facilities should reference these related standards to ensure comprehensive coverage of all dosimetry and irradiation process needs, from calibration to operational control.

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Keywords: gamma irradiation, radiation processing, dosimetry, absorbed dose, sterilization, food irradiation, medical device sterilization, polymer modification, routine dosimetry, absorbed-dose mapping, irradiation facility qualification, ASTM ISO/ASTM51702-13(2021).

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ISO/ASTM 51702:2013 (Reapproved 2021)(E)
Standard Practice for
Dosimetry in a Gamma Facility for Radiation Processing
This standard is issued under the fixed designation ISO/ASTM 51702; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
1. Scope 2. Referenced documents
1.1 This practice outlines the installation qualification pro- 2.1 ASTM Standards:
E170 Terminology Relating to Radiation Measurements and
gram for an irradiator and the dosimetric procedures to be
Dosimetry
followed during operational qualification, performance
qualification, and routine processing in facilities that process E2232 Guide for Selection and Use of Mathematical Meth-
ods for Calculating Absorbed Dose in Radiation Process-
products with ionizing radiation from radionuclide gamma
sources to ensure that product has been treated within a ing Applications
E2303 Guide for Absorbed-Dose Mapping in Radiation
predetermined range of absorbed dose. Other procedures re-
lated to operational qualification, performance qualification, Processing Facilities
E2628 Practice for Dosimetry in Radiation Processing
and routine processing that may influence absorbed dose in the
product are also discussed. E2701 Guide for Performance Characterization of Dosim-
NOTE 1—Dosimetry is only one component of a total quality assurance eters and Dosimetry Systems for Use in Radiation Pro-
program for adherence to good manufacturing practices used in radiation
cessing
processing applications.
2.2 ISO/ASTM Standards:
NOTE 2—ISO/ASTM Practices 51818 and 51649 describe dosimetric
51261 Practice for Calibration of Routine Dosimetry Sys-
procedures for low and high enery electron beam facilities for radiation
processing and ISO/ASTM Practice 51608 describes procedures for X-ray tems for Radiation Processing
(bremsstrahlung) facilities for radiation processing.
51539 Guide for Use of Radiation-Sensitive Indicators
51608 Practice for Dosimetry in an X-Ray (Bremsstrahlung)
1.2 For the radiation sterilization of health care products,
Facility for Radiation Processing
see ISO 11137-1. In those areas covered by ISO 11137-1, that
51649 Practice for Dosimetry in an Electron Beam Facility
standard takes precedence.
for Radiation Processing at Energies Between 300 KeV
1.3 This document is one of a set of standards that provides
and 25 KeV
recommendations for properly implementing and utilizing
51707 Guide for Estimating Uncertainties in Dosimetry for
dosimetry in radiation processing. It is intended to be read in
Radiation Processing
conjunction with ASTM Practice E2628.
51818 Practice for Dosimetry in an Electron Beam Facility
1.4 This standard does not purport to address all of the
for Radiation Processing at Energies Between 80 and 300
safety concerns, if any, associated with its use. It is the
keV
responsibility of the user of this standard to establish appro-
2.3 International Commission on Radiation Units and Mea-
priate safety, health, and environmental practices and deter-
surements (ICRU) Reports:
mine the applicability of regulatory limitations prior to use.
ICRU Report 85a Fundamental Quantities and Units for
1.5 This international standard was developed in accor-
Ionizing Radiation
dance with internationally recognized principles on standard-
2.4 ISO Standards:
ization established in the Decision on Principles for the
ISO 11137-1 Sterilization of health care products – Radia-
Development of International Standards, Guides and Recom-
tion – Part 1: Requirements for development, validation,
mendations issued by the World Trade Organization Technical
and routine control of a sterilization process for medical
Barriers to Trade (TBT) Committee.
devices
1 2
This practice is under the jurisdiction of ASTM Committee E61 on Radiation For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
Processing and is the direct responsibility of Subcommittee E61.03 on Dosimetry www.astm.org, or contact ASTM Customer Service at [e-mail]. For
Application, and is also under the jurisdiction of ISO/TC 85/WG 3. Annual Book of ASTM Standards volume information, refer to the standard’s
Current edition approved Oct. 1, 2021. Published April 2022. Originally Document Summary page on the ASTM website.
published as E 1702-95. Last previous ASTM edition E 1702–00. ASTM Available from the International Commission on Radiation Units and
ε1
E 1702–95 was adopted by ISO in 1998 with the intermediate designation ISO Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, USA.
15571:1998(E). The present International Standard ISO/ASTM 51702:2013 Available from International Organization for Standardization (ISO), 1 rue de
(2021)(E) is a reapproval of the last previous edition ISO/ASTM 51702–2013(E). Varembé, Case postale 56, CH-1211, Geneva 20, Switzerland, http://www.iso.ch.
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51702:2013 (2021)(E)
2.5 Joint Committee for Guides in Metrology (JCGM) 3.1.12 production run (for continuous-flow and shuffle-
Reports: dwell irradiations)—series of irradiation containers consisting
JCGM 100:2008, GUM 1995, with minor corrections, of materials or products having similar radiation-absorption
Evaluation of measurement data – Guide to the Expres- characteristics that are irradiated sequentially to a specified
sion of Uncertainty in Measurement range of absorbed dose.
3.1.13 simulated product—mass of material with absorption
3. Terminology
and scattering properties similar to those of the product,
3.1 Definitions:
material, or substance to be irradiated.
3.1.1 absorbed dose, D—quantity of ionizing radiation en-
3.1.13.1 Discussion—Simulated product is used during irra-
ergy imparted per unit mass of a specified material.The SI unit
diator characterization as a substitute for the actual product,
of absorbed dose is the gray (Gy), where 1 gray is equivalent
material or substance to be irradiated. When used in routine
to the absorption of 1 joule per kilogram of the specified
production runs in order to compensate for the absence of
material (1 Gy = 1 J/kg). The mathematical relationship is the
product, simulated product is sometimes referred to as com-
quotient of dε¯ by dm, where dε¯ is the mean incremental energy
pensating dummy. When used for absorbed-dose mapping,
imparted by ionizing radiation to matter of incremental mass
simulated product is sometimes referred to as phantom mate-
dm (see ICRU Report 85a).
rial.
D5 dε¯/dm (1)
3.1.14 timer setting—defined time interval during which
product is exposed to radiation.
3.1.2 absorbed-dose mapping—measurement of absorbed
3.1.14.1 Discussion—Forashuffle-dwellirradiatorthetimer
dose within an irradiation product to produce a one-, two- or
setting is the time interval from the start of one shuffle-dwell
three-dimensionaldistributionofabsorbeddose,thusrendering
cycle to the start of the next shuffle-dwell cycle. For a
a map of absorbed-dose values.
stationary irradiator, the timer setting is the total irradiation
3.1.3 calibration curve—expression of the relation between
time.
indication and corresponding measured quantity value.
3.1.3.1 Discussion—In radiation processing standards, the 3.2 Definitions of other terms used in this standard that
term “dosimeter response” is generally used for “indication.”
pertain to radiation measurement and dosimetry may be found
in ASTM Terminology E170. Definitions in E170 are compat-
3.1.4 compensating dummy—See simulated product.
ible with ICRU Report 85a; ICRU Report 85a, therefore, may
3.1.5 dosimeter response—reproducible, quantifiable radia-
be used as an alternative reference.
tion effect produced in the dosimeter by ionizing radiation.
3.1.6 dosimeter set—one or more dosimeters used to mea-
4. Significance and use
sure the absorbed dose at a location and whose average reading
4.1 Various products and materials routinely are irradiated
is used as the absorbed-dose measurement at that location.
at predetermined doses in gamma irradiation facilities to
3.1.7 dosimetry system—system used for absorbed dose,
reduce their microbial population or to modify their character-
consisting of dosimeters, measurement instruments and their
istics. Dosimetry requirements may vary depending upon the
associatedreferencestandards,andproceduresforthesystem’s
irradiation application and end use of the product. Some
use.
examples of irradiation applications where dosimetry may be
3.1.8 installation qualification (IQ)—process of obtaining
used are:
and documenting evidence that equipment has been provided
4.1.1 Sterilization of medical devices,
and installed in accordance with specifications.
4.1.2 Treatment of food for the purpose of parasite and
pathogen control, insect disinfestation, and shelf life extension,
3.1.9 irradiation container—holder in which product is
4.1.3 Disinfection of consumer products,
placed during the irradiation process.
4.1.4 Cross-linking or degradation of polymers and
3.1.9.1 Discussion—“Irradiation container” is often referred
elastomers,
tosimplyas“container”andcanbeacarrier,cart,tray,product
4.1.5 Polymerization of monomers and grafting of mono-
carton, pallet, product package or other holder.
mers onto polymers,
3.1.10 operational qualification (OQ)—processofobtaining
4.1.6 Enhancement of color in gemstones and other
and documenting evidence that installed equipment operates
materials,
within predetermined limits when used in accordance with its
4.1.7 Modification of characteristics of semiconductor
operational procedures.
devices, and
3.1.11 performance qualification (PQ)—process of obtain-
4.1.8 Research on materials effects.
ing and documenting evidence that the equipment, as installed
NOTE 3—Dosimetry is required for regulated irradiation processes such
and operated in accordance with operational procedures, con-
assterilizationofmedicaldevicesandthetreatmentoffood.Itmaybeless
sistently performs in accordance with predetermined criteria important for other industrial processes, for example, polymer
modification, which can be evaluated by changes in the physical and
and thereby yields product meeting its specification.
chemical properties of the irradiated materials.
4.2 An irradiation process usually requires a minimum
Document produced by Working Group 1 of the Joint Committee for Guides in
absorbeddosetoachievetheintendedeffect.Therealsomaybe
Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
www.bipm.org). a maximum absorbed dose that the product can tolerate and
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51702:2013 (2021)(E)
still meet its functional or regulatory specifications. Dosimetry are followed by periods of time during which the irradiation
is essential to the irradiation process since it is used to container is stationary (shuffle-dwell), or may be irradiated at
determine both of these limits and to confirm that the product fixed locations (stationary).
is routinely irradiated within these limits. 6.3.1 The desired absorbed dose for the product is obtained
by controlling by the conveyor speed (continuous conveyance)
4.3 The absorbed-dose distribution within the product de-
or the timer setting (shuffle-dwell or stationary).
pends on the overall product dimensions and mass, irradiation
6.3.2 For many commercial irradiators, the irradiation con-
geometry, and source activity distribution.
tainers move in one or more parallel rows on each side of a
4.4 Before an irradiation facility can be used, it must be
vertical rectangular source array. The irradiation containers
qualified to determine its effectiveness in reproducibly deliv-
may move past a source array in a configuration in which the
ering known, controllable absorbed doses. This involves test-
sourceeitherextendsaboveandbelowtheirradiationcontainer
ing the process equipment, calibrating the equipment and
(source overlap) or the irradiation container extends above and
dosimetry system, and characterizing the magnitude, distribu-
below the source (product overlap). In the latter configuration,
tion and reproducibility of the absorbed dose delivered by the
the irradiation container moves past the source at two or more
irradiator for a range of product densities.
levels.
6.3.2.1 In bulk-flow irradiators, products such as grain or
4.5 To ensure consistent and reproducible dose delivery in a
qualified process, routine process control requires documented flour flow in loose form past the source. The desired absorbed
dose is obtained by controlling the flow rate.
product handling procedures before and after irradiation, con-
sistent product loading configuration, control and monitoring
6.4 Because of mechanical speed limitations, various tech-
of critical process parameters, routine product dosimetry and
niques may be used to reduce the absorbed-dose rates for low
documentation of the required activities.
absorbed-dose applications. These techniques include using
only a portion of the source (for example, raising only one of
5. Radiation source characteristics
several source racks to the irradiation position), using
5.1 The radiation source used in a facility considered in this
attenuators,andirradiatingatgreaterdistancesfromthesource.
60 137
practice consists of sealed elements of Co or Cs which are
typically linear rods or “pencils” arranged in one or more
7. Dosimetry system calibration
planar or cylindrical arrays.
7.1 The dosimetry system shall be calibrated in accordance
5.2 A cobalt-60 source emits photons with energies of
with Practice 51261, and the user’s procedures, which should
approximately 1.17 and 1.33 MeV in nearly equal proportions.
specify details of the calibration process and quality assurance
A cesium-137 source emits photons with energies of approxi-
requirements.
mately 0.662 MeV (1).
7.2 The dosimetry system calibration is part of a measure-
60 137
5.3 The radioactive decay half-lives for Co and Cs are
ment management system.
regularly reviewed and updated. The most recent publication
by the National Institute of Standards and Technology gave
8. Installation qualification
values of 1925.20 (6 0.25) days for Co and 11018.3 (6 9.5)
8.1 Objective—The purpose of an installation qualification
days for Cs (2).
program is to demonstrate that the irradiator with its associated
5.4 Between source replenishments, removals, or
processing equipment and measurement instruments have been
redistributions, the variation in the source output is solely due
delivered and installed in accordance with their specifications.
to the steady reduction in the activity caused by the radioactive
Installation qualification includes documentation of the irradia-
decay.
tor and the associated processing equipment and measurement
instruments, establishment of the testing, operation and cali-
6. Types of facilities
bration procedures for their use, and verification that they
operate according to specifications. An effective installation
6.1 The design of an irradiator affects the delivery of
absorbed dose to a product. Therefore, the irradiator design qualification program will ensure consistent and correct opera-
should be considered when performing the absorbed-dose tionoftheirradiatorsoastodelivertherequiredabsorbeddose
measurements described in Sections 9 through 11. to a product.
6.2 Products may be moved to locations where the irradia- 8.2 Equipment Documentation—Document descriptions of
tion will take place, either while the source is fully shielded the irradiator and the associated processing equipment and
(batch operation) or while the source is exposed (continuous measurement instruments installed at the facility. This docu-
operation). mentation shall be retained for the life of the facility. At a
minimum, it shall include:
6.3 Productsmaybetransportedpastthesourceatauniform
8.2.1 Description of the location of the irradiator within the
and controlled speed (continuous conveyance), may undergo a
operator’s premises in relation to the areas assigned and the
series of shuffle-dwell cycles during which product movements
means established for ensuring the segregation of un-irradiated
products from irradiated products,
8.2.2 Description of the operating procedure of the
The boldface numbers in parentheses refer to the bibliography at the end of this
practice. irradiator,
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51702:2013 (2021)(E)
8.2.3 Description of the construction and operation of the source-to-product distance, the irradiation geometry (for
product handling equipment, example, 1- or 2-sided irradiation, multiple passes), and the
irradiator pathways.
8.2.4 Description of the materials and construction of any
9.1.2 Examples of a process parameter are the timer setting
containers used to hold products during irradiation,
or conveyor speed.
8.2.5 Description of the process control system, and
8.2.6 Description of any modifications made during and 9.2 Absorbed-dose Mapping—Perform operational qualifi-
cation absorbed-dose mapping to characterize the irradiator
after installation.
with respect to the dose distribution and reproducibility of
8.3 Testing, Operation and Calibration Procedures—
absorbed-dose delivery. Map the absorbed-dose distribution by
Establish and implement standard operating procedures for the
a three-dimensional placement of dosimeter sets in an irradia-
testing, operation and calibration (if necessary) of the installed
tion container containing homogeneous simulated product. For
irradiator and its associated processing equipment and mea-
guidance on performing absorbed-dose mapping see ASTM
surement instruments.
Guide E2303.
8.3.1 Testing Procedures—These procedures describe the
9.2.1 The amount of homogeneous simulated product in
testing methods used to ensure that the installed irradiator and
each irradiation container should be the amount expected
its associated processing equipment and measurement instru-
during typical production runs or should be the maximum
ments operate according to specification.
design volume for the irradiation container.
8.3.2 Operation Procedures—These procedures describe
9.2.2 Select placement patterns to identify the locations of
how to operate the irradiator and its associated processing
the absorbed-dose maxima and minima (for example, see Fig.
equipment and measurement instruments during routine opera-
1). Place more dosimeter sets in these locations and fewer
tion.
dosimeter sets in locations likely to receive intermediate
8.3.3 Calibration Procedures—These procedures describe
absorbed doses. Dosimetry data from previously qualified
periodic calibration and verification methods that ensure that
irradiators of the same design or calculations using mathemati-
the installed processing equipment and measurement instru-
cal models (see ASTM Guide E2232) may provide useful
ments continue to operate within specifications. The frequency
information for determining the number and location of do-
of calibration for some equipment and instruments might be
simeters for this qualification process.
specified by a regulatory authority. Some equipment and
NOTE 4—Dosimeter strips or sheets may be used to increase spatial
instruments might be required to be traceable to a national or
resolution of the absorbed-dose map, if the use of individual dosimeters is
other accredited standards laboratory.
inadequate.
8.4 Testing of Processing Equipment and Measurement 9.2.3 Map a sufficient number of irradiation containers to
Instruments—Verify that the installed processing equipment allow the estimation of the variability of the magnitude and
and measurement instruments operate within their design distribution of the absorbed dose. Dosimetry data from previ-
specifications by following the testing procedures noted in ously qualified irradiators of the same design may provide
8.3.1. If necessary, ensure that the equipment and instruments useful information for determining the number of irradiation
have been calibrated according to the calibration procedures containers for this qualification.
noted in 8.3.3. 9.2.4 The number of irradiation containers preceding and
following the dose-mapped irradiation containers shall be
8.4.1 Test all processing equipment to verify satisfactory
sufficient to effectively simulate an irradiator filled with the
operation of the irradiator within the design specifications.
product.
Document all testing results.
9.2.5 If the facility anticipates irradiating products spanning
8.4.2 Test the performance of the measurement instruments
a range of densities, perform absorbed-dose mapping over the
to ensure that they are functioning according to performance
density range. This is necessary since differences in bulk
specifications. Document all testing results.
density of the product in the irradiation container may result in
8.4.3 If any modification or change is made to the process-
changes in the magnitudes and locations of the minimum and
ing equipment or measurement instruments during installation
maximum absorbed doses, which, in turn, could change the
qualification, they shall be re-tested.
dose-uniformity ratio.
9.2.6 For some irradiator designs, when the irradiator is
9. Operational qualification
running near the maximum mechanical speed, the absorbed
9.1 Objective—The purpose of dosimetry in the operational
dose may not be directly related to the timer setting or
qualification of a gamma irradiation facility is to establish
conveyor speed. This effect should be considered and, if
baseline data for evaluating facility effectiveness,
necessary, quantified.
predictability, and reproducibility for the range of operating
9.2.7 Repeat the absorbed-dose mapping (9.2.1 – 9.2.6) for
conditions of the irradiator expected to be used for irradiating
each different irradiator pathway to be used for routine product
product. The absorbed dose received by any portion of product
processing (Section 11).
in an irradiation container depends on the irradiator design, the
9.2.8 The procedures for absorbed-dose mapping outlined
source activity and geometry and the process parameters.
in this section may not be feasible for some types of bulk-flow
9.1.1 Examples of irradiator design characteristics that af- irradiators. In such cases, minimum and maximum absorbed
fect the absorbed dose are the radiation source characteristics, doses should be estimated by using an appropriate number of
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51702:2013 (2021)(E)
FIG. 1 An example of a dosimeter placement array in a three-dimensional grid pattern for an o
...