ASTM ISO/ASTM51608-15(2022)
(Practice)Standard Practice for Dosimetry in an X-Ray (Bremsstrahlung) Facility for Radiation Processing at Energies between 50 keV and 7.5 MeV
Standard Practice for Dosimetry in an X-Ray (Bremsstrahlung) Facility for Radiation Processing at Energies between 50 keV and 7.5 MeV
SIGNIFICANCE AND USE
4.1 A variety of products and materials are irradiated with X-radiation to modify their characteristics and improve the economic value or to reduce their microbial population for health-related purposes. Dosimetry requirements might vary depending on the type and end use of the product. Some examples of irradiation applications where dosimetry may be used are:
4.1.1 Sterilization of health care products;
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 Curing composite material;
4.1.6 Polymerization of monomers and oligomer and grafting of monomers onto polymers;
4.1.7 Enhancement of color in gemstones and other materials;
4.1.8 Modification of characteristics of semiconductor devices; and
4.1.9 Research on materials effects of irradiation.
Note 3: Dosimetry with measurement traceability and with known measurement uncertainty is required for regulated irradiation processes, such as the sterilization of health care products and treatment of food. Dosimetry may be less important for other industrial processes, such as polymer modification, which can be evaluated by changes in the physical properties of the irradiated materials. Nevertheless, routine dosimetry may be used to monitor the reproducibility of the radiation process.
4.2 Radiation processing specifications usually include a pair of absorbed-dose limits: a minimum value to ensure the intended beneficial effect and a maximum value that the product can tolerate while still meeting its functional or regulatory specifications. For a given application, one or both of these values may be prescribed by process specifications or regulations. Knowledge of the dose distribution within irradiated material is essential to help meet these requirements. Dosimetry is essential to the radiation process since it i...
SCOPE
1.1 This practice outlines the dosimetric procedures to be followed during installation qualification, operational qualification, performance qualification and routine processing at an X-ray (bremsstrahlung) irradiator. 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 51649, 51818 and 51702 describe dosimetric procedures for electron beam and gamma facilities for radiation processing.
1.2 For radiation sterilization of health care products, see ISO 11137-1, Sterilization of health care products – Radiation – Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices. In those areas covered by ISO 11137-1, that standard takes precedence.
1.3 For irradiation of food, see ISO 14470, Food irradiation – Requirements for development, validation and routine control of the process of irradiation using ionizing radiation for the treatment of food. In those areas covered by ISO 14470, that standard takes precedence.
1.4 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 ISO/ASTM Practice 52628, “Practice for Dosimetry in Radiation Processing”.
1.5 In contrast to monoenergetic gamma radiation, the X-ray energy spectrum extends from low values (about 35 keV) up to the maximum energy of the electrons incident on the X-ray target (see Section 5 and Annex A1).
1.6 Information about effective or regulatory dose limits and energy limits for X-ray applications is not within the scope of this practice.
1.7 This ...
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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 51608:2015 (Reapproved 2022)(E)
Standard Practice for
Dosimetry in an X-Ray (Bremsstrahlung) Facility for
Radiation Processing at Energies between 50 keV and 7.5
MeV
This standard is issued under the fixed designation ISO/ASTM 51608; 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 keV) up to the maximum energy of the electrons incident on
the X-ray target (see Section 5 and Annex A1).
1.1 This practice outlines the dosimetric procedures to be
followed during installation qualification, operational
1.6 Informationabouteffectiveorregulatorydoselimitsand
qualification, performance qualification and routine processing
energy limits for X-ray applications is not within the scope of
at an X-ray (bremsstrahlung) irradiator. Other procedures
this practice.
related to operational qualification, performance qualification
1.7 This standard does not purport to address all of the
androutineprocessingthatmayinfluenceabsorbeddoseinthe
safety concerns, if any, associated with its use. It is the
product are also discussed.
responsibility of the user of this standard to establish appro-
NOTE 1—Dosimetry is only one component of a total quality assurance
priate safety and health practices and determine the applica-
program for adherence to good manufacturing practices used in radiation
bility of regulatory limitations prior to use.
processing applications.
NOTE 2—ISO/ASTM Practices 51649, 51818 and 51702 describe
dosimetric procedures for electron beam and gamma facilities for radia-
2. Referenced documents
tion processing.
2.1 ASTM Standards:
1.2 For radiation sterilization of health care products, see
E170Terminology Relating to Radiation Measurements and
ISO 11137-1, Sterilization of health care products – Radiation
Dosimetry
– Part 1: Requirements for development, validation and
E2232Guide for Selection and Use of Mathematical Meth-
routine control of a sterilization process for medical devices.In
ods for CalculatingAbsorbed Dose in Radiation Process-
those areas covered by ISO 11137-1, that standard takes
ing Applications
precedence.
E2303Guide for Absorbed-Dose Mapping in Radiation
1.3 Forirradiationoffood,seeISO14470, Food irradiation
Processing Facilities
– Requirements for development, validation and routine con-
2.2 ISO/ASTM Standards:
trol of the process of irradiation using ionizing radiation for
51261Practice for Calibration of Routine Dosimetry Sys-
the treatment of food. In those areas covered by ISO 14470,
tems for Radiation Processing
that standard takes precedence.
51539Guide for Use of Radiation-Sensitive Indicators
1.4 This document is one of a set of standards that provides
51649Practice for Dosimetry in an Electron Beam Facility
recommendations for properly implementing and utilizing
for Radiation Processing at Energies Between 300 keV
dosimetry in radiation processing. It is intended to be read in
and 25 MeV
conjunction with ISO/ASTM Practice 52628, “Practice for
51702Practice for Dosimetry in a Gamma Facility for
Dosimetry in Radiation Processing”.
Radiation Processing
51707Guide for Estimating Uncertainties in Dosimetry for
1.5 In contrast to monoenergetic gamma radiation, the
Radiation Processing
X-ray energy spectrum extends from low values (about 35
51818Practice for Dosimetry in an Electron Beam Facility
for Radiation Processing at Energies Between 80and 300
keV
This practice is under the jurisdiction of ASTM Committee E61 on Radiation
52628Practice for Dosimetry in Radiation Processing
Processing and is the direct responsibility of Subcommittee E61.03 on Dosimetry
Application, and is also under the jurisdiction of ISO/TC 85/WG 3.
Current edition approved Dec. 1, 2022. Published December 2022. Originally
published asASTM E 1608–94. Last previousASTM edition E 1608–00.ASTM E
1608–94 was adopted by ISO in 1998 with the intermediate designation ISO For referenced ASTM or ISO/ASTM standards, visit the ASTM website,
15567:1998(E). The present International Standard ISO/ASTM www.astm.org, or contact ASTM Customer Service at service@astm.org. For
51608:2015(2022)(E) is a reapproval of the last previous edition ISO/ASTM Annual Book of ASTM Standards volume information, refer to the standard’s
51608:2015(E), which replaced ISO/ASTM 51608:2005(E). Document Summary page on the ASTM website.
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51608:2015 (2022)(E)
52701Guide for Performance Characterization of Dosim- 3.1.3 beam width—dimension of the irradiation zone per-
etersandDosimetrySystemsforuseinRadiationProcess- pendiculartothedirectionofproductmovement,ataspecified
ing distance from the accelerator window.
3.1.3.1 Discussion—For graphic illustration, see ISO/
2.3 ISO Standards:
ASTM Practice 51649. This term usually applies to electron
ISO 11137-1Sterilization of health care products – Radia-
irradiation.
tion – Part 1: Requirements for development, validation
and routine control of a sterilization process for medical
3.1.4 bremsstrahlung—broad-spectrum electromagnetic ra-
devices
diation emitted when an energetic charged particle is influ-
ISO 14470 Food irradiation – Requirements for the
enced by a strong electric or magnetic field, such as that in the
development,validationandroutinecontroloftheprocess
vicinity of an atomic nucleus.
of irradiation using ionizing radiation for the treatment of
3.1.4.1 Discussion—In radiation processing, bremsstrahl-
food
ung photons with sufficient energy to cause ionization are
2.4 International Commission on Radiation Units and Mea- generated by the deceleration or deflection of energetic elec-
surements (ICRU) Reports:
trons in a target material. When an electron passes close to an
ICRU Report 14Radiation Dosimetry: X Rays and Gamma atomicnucleus,thestrongcoulombfieldcausestheelectronto
RayswithMaximumPhotonEnergiesBetween0.6and50
deviate from its original motion. This interaction results in a
MeV loss of kinetic energy by the emission of electromagnetic
ICRU Report 34Dosimetry of Pulsed Radiation
radiation.Suchencountersareuncontrolledandtheyproducea
ICRU Report 35Radiation Dosimetry: Electron Beams with continuous photon energy distribution that extends up to the
Energies Between 1 and 50 MeV
maximum kinetic energy of the incident electron. The
ICRU Report 37Stopping Powers for Electrons and Posi- bremsstrahlung energy spectrum depends on the electron
trons energy, the composition and thickness of the X-ray target, and
ICRU Report 80Dosimetry Systems for Use in Radiation theemissiondirectionofphotonangleofemissionwithrespect
Processing to the incident electron.
ICRU Report 85aFundamental Quantities and Units for
3.1.5 charged-particle equilibrium (referred to as electron
Ionizing Radiation
equilibrium in the case of electrons set in motion by photon-
2.5 Joint Committee for Guides in Metrology (JCGM)
beam irradiation of a material)—condition in which the kinetic
Report:
energy of charged particles (or electrons), excluding rest mass,
JCGM 100:2008, GUM 1995, with minor corrections,
entering an infinitesimal volume of the irradiated material
Evaluation of measurement data–Guide to the expression
equals the kinetic energy of charge particles (or electrons)
of uncertainty in measurement
emerging from it.
3.1.6 dose uniformity ratio—ratio of the maximum to the
3. Terminology
minimum absorbed dose within the irradiated product.
3.1 Definitions:
3.1.6.1 Discussion—The concept is also referred to as the
3.1.1 absorbed dose (D)—quantity of ionizing radiation
max/min dose ratio.
energy imparted per unit mass of a specified material. The SI
3.1.7 dosimeter—device that, when irradiated, exhibits a
unit of absorbed dose is the gray (Gy), where 1 gray is
quantifiable change that can be related to absorbed dose in a
equivalent to the absorption of 1 joule per kilogram of the
given material using appropriate measurement instrument(s)
specified material (1 Gy = 1 J/kg). The mathematical relation-
and procedures.
ship is the quotient of dε by dm, where dε is the mean
3.1.8 dosimeter response—reproducible, quantifiable effect
incremental energy imparted by ionizing radiation to matter of
produced in the dosimeter by ionizing radiation.
incremental mass dm (see ICRU Report 85a).
3.1.9 dosimetry system—system used for measuring ab-
D 5dε/dm (1)
sorbed dose, consisting of dosimeters, measurement instru-
3.1.2 beam length—dimension of the irradiation zone along
ments and their associated reference standards, and procedures
thedirectionofproductmovement,ataspecifieddistancefrom
for the system’s use.
the accelerator window.
3.1.10 electron energy—kinetic energy of an electron.
3.1.2.1 Discussion—Beam length is perpendicular to beam
width and to the electron beam axis. In case of product that is 3.1.10.1 Discussion—Unit is usually electron volt (eV),
kiloelectron volt (keV), or megaelectron volt (MeV). 1 eV is
stationary during irradiation, ‘beam length’ and ‘beam width’
may be interchangeable. the kinetic energy acquired by a single electron accelerated
throughapotentialdifferenceof1V.1eVisequaltoenergyof
-19
1.602 × 10 joules.
Available from the International Organization for Standardization, 1 Rue de
3.1.11 electron energy spectrum—particle fluence distribu-
Varembé, Case Postale 56, CH–1211, Geneva 20, Switzerland.
tion of electrons as a function of energy.
Available from the International Commission on Radiation Units and
Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814, U.S.A.
3.1.12 installation qualification (IQ)—process of obtaining
DocumentproducedbyWorkingGroup1oftheJointCommitteeforGuidesin
and documenting evidence that equipment has been provided
Metrology (JCGM/WG 1). Available free of charge at the BIPM website (http://
www.bipm.org). and installed in accordance with its specifications.
© ISO/ASTM International 2022 – All rights reserved
ISO/ASTM 51608:2015 (2022)(E)
3.1.13 irradiation container—holder in which product is metal with a high atomic number (such as tantalum), high
placed during the irradiation process. melting temperature, and high thermal conductivity.
3.1.13.1 Discussion—“Irradiation container” is often re-
3.3 Definitions of other terms used in this standard that
ferred to simply as “container” and can be a carrier, cart, tray,
pertain to radiation measurement and dosimetry may be found
product carton, pallet, product package or other holder.
inASTM Terminology E170. Definitions in E170 are compat-
3.1.14 measurement management system—set of interre-
ible with ICRU Report 85a, which may be used as an
latedorinteractingelementsnecessarytoachievemetrological
alternative reference.
confirmation and continual control of measurement processes.
3.1.15 operational qualification (OQ)—processofobtaining 4. Significance and use
and documenting evidence that installed equipment operates
4.1 A variety of products and materials are irradiated with
within predetermined limits when used in accordance with its
X-radiation to modify their characteristics and improve the
operational procedures.
economic value or to reduce their microbial population for
3.1.16 performance qualification (PQ)—process of obtain-
health-related purposes. Dosimetry requirements might vary
ing and documenting evidence that the equipment, as installed
depending on the type and end use of the product. Some
and operated in accordance with operational procedures, con-
examples of irradiation applications where dosimetry may be
sistently performs in accordance with predetermined criteria
used are:
and thereby yields product meeting its specification.
4.1.1 Sterilization of health care products;
3.1.17 process load—volume of material with a specified
4.1.2 Treatment of food for the purpose of parasite and
loading configuration irradiated as a single entity.
pathogencontrol,insectdisinfestation,andshelflifeextension;
3.1.18 processing category—group of different product that
4.1.3 Disinfection of consumer products;
can be processed together.
4.1.4 Cross-linking or degradation of polymers and elasto-
3.1.18.1 Discussion—Processing categories can be based
mers;
on, for instance, composition, density or dose requirements.
4.1.5 Curing composite material;
3.1.19 reference material—homogeneousmaterialofknown
4.1.6 Polymerization of monomers and oligomer and graft-
radiation absorption and scattering properties used to establish
ing of monomers onto polymers;
characteristics of the irradiation process, such as scan
4.1.7 Enhancement of color in gemstones and other mate-
uniformity,depth-dosedistribution,throughputrate,andrepro-
rials;
ducibility of dose delivery.
4.1.8 Modification of characteristics of semiconductor de-
3.1.20 simulated product—material with radiation attenua-
vices; and
tion and scattering properties similar to those of the product,
4.1.9 Research on materials effects of irradiation.
material or substance to be irradiated.
3.1.20.1 Discussion—Simulatedproductisusedduringirra-
NOTE 3—Dosimetry with measurement traceability and with known
diator characterization as a substitute for the actual product,
measurement uncertainty is required for regulated irradiation processes,
material or substance to be irradiated. When used in routine such as the sterilization of health care products and treatment of food.
Dosimetry may be less important for other industrial processes, such as
production runs in order to compensate for the absence of
polymer modification, which can be evaluated by changes in the physical
product, simulated product is sometimes referred to as com-
propertiesoftheirradiatedmaterials.Nevertheless,routinedosimetrymay
pensating dummy. When used for absorbed-dose mapping,
be used to monitor the reproducibility of the radiation process.
simulated product is sometimes referred to as phantom mate-
4.2 Radiation processing specifications usually include a
rial.
pair of absorbed-dose limits: a minimum value to ensure the
3.2 Definitions of Terms Specific to This Standard:
intended beneficial effect and a maximum value that the
3.2.1 X-radiation—ionizing electromagnetic radiation,
product can tolerate while still meeting its functional or
which includes both bremsstrahlung and the characteristic
regulatory specifications. For a given application, one or both
radiation emitted when atomic electrons make transitions to
of these values may be prescribed by process specifications or
more tightly bound states. See bremsstrahlung.
regulations. Knowledge of the dose distribution within irradi-
3.2.1.1 Discussion—In radiation processing application
...
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