1、ISO/ASTM 52303:2015(E)An American National StandardStandard Guide forAbsorbed-Dose Mapping in Radiation Processing Facilities1This standard is issued under the fixed designation ISO/ASTM 52303; the number immediately following the designation indicates theyear of original adoption or, in the case of
2、 revision, the year of last revision.1. Scope1.1 This document provides guidance in determiningabsorbed-dose distributions (mapping) in products, materialsor substances irradiated in gamma, X-ray (bremsstrahlung) andelectron beam facilities.NOTE 1For irradiation of food and the radiation sterilizati
3、on of healthcare products, specific ISO and ISO/ASTM standards containing dosemapping requirements exist. See ISO/ASTM Practices 51431, 51608,51649, 51702 and 51818 and ISO 11137-1. Regarding the radiationsterilization of health care products, in those areas covered by ISO11137-1, that standard take
4、s precedence.1.2 This guide is one of a set of standards that providesrecommendations for properly implementing dosimetry inradiation processing. it is intended to be read in conjunctionwith ISO/ASTM 52628.1.3 Methods of analyzing the dose map data are described.Examples are provided of statistical
5、methods that may be usedto analyze dose map data.1.4 Dose mapping for bulk flow processing and fluidstreams is not discussed.1.5 Dosimetry is an element of a total quality managementsystem for an irradiation facility. Other controls besides do-simetry may be required for specific applications such a
6、smedical device sterilization and food preservation.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of
7、 regulatory requirements prior to use.2. Referenced Documents2.1 ASTM Standards:2E170 Terminology Relating to Radiation Measurements andDosimetryE178 Practice for Dealing With Outlying ObservationsE2232 Guide for Selection and Use of Mathematical Meth-ods for Calculating Absorbed Dose in Radiation P
8、rocess-ing Applications2.2 ISO/ASTM Standards:251261 Guide for Selection and Calibration of DosimetrySystems for Radiation Processing51431 Practice for Dosimetry in Electron Beam and X-Ray(Bremsstrahlung) Irradiation Facilities for Food Process-ing51608 Practice for Dosimetry in an X-ray (Bremsstrah
9、lung)Facility for Radiation Processing51649 Practice for Dosimetry in an Electron Beam Facilityfor Radiation Processing at Energies between 300 keVand25 MeV51702 Practice for Dosimetry in a Gamma Irradiation Facil-ity for Radiation Processing51707 Guide for Estimating Uncertainties in Dosimetry forR
10、adiation Processing51818 Practice for Dosimetry in an Electron Beam Facilityfor Radiation Processing at Energies between 80 and 300keV52628 Practice for Dosimetry in Radiation Processing2.3 International Commission on Radiation Units and Mea-surements Reports:3ICRU Report 85a Fundamental Quantities
11、and Units forIonizing Radiation2.4 International Organization for Standardization:4ISO 11137-1 Sterilization of health care products Radia-tion Part 1: Requirements for development, validation,and routine control of a sterilization process for medicaldevices2.5 Joint Committee for Guides in Metrolog
12、y (JCGM)Reports:JCGM 100:2008 GUM 1995 , with minor corrections,Evaluation of measurement data Guide to the expressionof uncertainty in measurement51This guide is under the jurisdiction of ASTM Committee E61 on RadiationProcessing and is the direct responsibility of Subcommittee E61.03 on DosimetryA
13、pplication and is also under the jurisdiction of ISO/TC 85/WG 3.Current edition approved Feb. 9, 2015. Published June 2015. Originallypublished as ASTM E230303. Last previous ASTM edition E2303111. Thepresent International Standard ISO/ASTM 523032015(E) replaces ASTME2303111.2For referenced ASTM and
14、 ISO/ASTM standards, visit the ASTM website,www.astm.org, or contact ASTM Customer Service at serviceastm.org. ForAnnual Book of ASTM Standards volume information, refer to the standardsDocument Summary page on the ASTM website.3Available from International Commission on Radiation Units andMeasureme
15、nts, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.4Available from International Organization for Standardization (ISO), 1 rue deVaremb, Case postale 56, CH-1211, Geneva 20, Switzerland.5Document produced by Working Group 1 of the Joint Committee for Guides inMetrology (JCGM/WG 1). Available fre
16、e of charge at the BIPM website (http:/www.bipm.org). ISO/ASTM International 2015 All rights reserved1JCGM 200:2012, VIM International vocabulary of metrol-ogy Basis and general concepts and associated terms63. Terminology3.1 Definitions:3.1.1 absorbed-dose mappingmeasurement of absorbeddose within
17、an irradiated product to produce a one-, two- orthree-dimensional distribution map of absorbed dose.3.1.1.1 DiscussionFor a process load, such a dose map isobtained using dosimeters placed at specified locations withinthe process load.3.1.2 calibration curve (VIM:2008)expression of the re-lation bet
18、ween indication and corresponding measured quantityvalue.3.1.2.1 DiscussionIn radiation processing standards, theterm “dosimeter response” is generally used for “indication.”3.1.3 dose map, dose mappingsee absorbed-dose map-ping.3.1.4 dose uniformity ratioratio of the maximum to theminimum absorbed
19、dose within the irradiated product.3.1.4.1 DiscussionThe concept is also referred to as themax/min dose ratio. Product generally refers to the “processload.”3.1.5 dose zonea region or discrete point(s) within aprocess load that receives the same absorbed dose within thestatistical uncertainty of the
20、 irradiation process and absorbed-dose measurement(s).3.1.6 installation qualification (IQ)process of obtainingand documenting evidence that equipment has been providedand installed in accordance with its specification.3.1.7 irradiation containerholder in which process load istransported through the
21、 irradiator.3.1.7.1 Discussion“Irradiation container” is often referredto simply as “container” and can be a carrier, cart, try, productcarton, pallet, product package or other holder.3.1.8 operational qualification (OQ)process of obtainingand documenting evidence that installed equipment operateswi
22、thin predetermined limits when used in accordance with itsoperational procedures.3.1.9 performance qualification (PQ)process of obtainingand documenting evidence that the equipment, as installed andoperated in accordance with operational procedures, consis-tently performs in accordance with predeter
23、mined criteria andthereby yields product meeting its specification.3.1.10 process loada volume of material with a specifiedproduct loading configuration irradiated as a single entity.3.1.11 processing categorygroup of different product thatcan be processed together.3.1.11.1 DiscussionProcessing cate
24、gories can be basedon, for instance, composition, density or dose requirements.3.1.12 reference materialhomogeneous material of knownradiation absorption and scattering properties used to establishcharacteristics of the irradiation process, such as scanuniformity, depth-dose distribution, throughput
25、 rate, and repro-ducibility of dose delivery.3.1.13 routine monitoring positionposition where ab-sorbed dose is monitored during routine processing to ensurethat the product is receiving the absorbed dose specified for theprocess.3.1.13.1 DiscussionThis position may be a location ofminimum or maximu
26、m dose in the process load or it may be analternate convenient location in, on or near the process loadwhere the relationship of the dose at this position with theminimum and maximum dose has been established.3.1.14 simulated productmaterial with absorption andscattering properties similar to those
27、of the product, material orsubstance to be irradiated.3.1.14.1 DiscussionSimulated product is used during irra-diator characterization as a substitute for the actual product,material or substance to be irradiated. When used in routineproduction runs in order to compensate for the absence ofproduct,
28、simulated product is sometimes referred to as com-pensating dummy. When used for absorbed-dose mapping,simulated product is sometimes referred to as phantom mate-rial.3.2 Definitions of other terms used in this standard thatpertain to radiation measurement and dosimetry may be foundin Terminology E1
29、70. Definitions in E170 are compatible withICRU Report 60; that document, therefore, may be used as analternative reference.4. Significance and use4.1 This guide is one of a set of guides and practices thatprovide recommendations for properly implementing dosim-etry in radiation processing. In order
30、 to understand andeffectively use this and other dosimetry standards, considerfirst “Practice for Dosimetry in Radiation Processing,” ASTM/ISO 52628, which describes the basic requirements that applywhen making absorbed dose measurements in accordance withthe ASTM E10.01 series of dosimetry standard
31、s. In addition,ASTM/ISO 52628 provides guidance on the selection ofdosimetry systems and directs the user to other standards thatprovide information on individual dosimetry systems, calibra-tion methods, uncertainty estimation and radiation processingapplications.4.2 Radiation processing is carried
32、out under fixed pathconditions where (a) a process load is automatically movedthrough the radiation field by mechanical means or (b)aprocess load is irradiated statically by manually placing prod-uct at predetermined positions before the process is started. Inboth cases the process is controlled in
33、such a manner that theprocess load position(s) and orientation(s) are reproduciblewithin specified limits.NOTE 2Static irradiation encompasses irradiation of the process loadusing either manual rotation, no rotation or automated rotation.4.3 Some radiation processing facilities that utilize a fixedc
34、onveyor path for routine processing may also characterize aregion within the radiation field for static radiation processing,sometimes referred to as “Off Carrier” processing.6Document produced by Working Group 2 of the Joint Committee for Guides inMetrology (JCGM/WG 2). Available free of charge at
35、the BIPM website (http:/www.bipm.org).ISO/ASTM 52303:2015(E)2 ISO/ASTM International 2015 All rights reserved4.4 Many radiation processing applications require a mini-mum absorbed dose (to achieve a desired effect or to fulfill alegal requirement), and a maximum absorbed dose (to ensurethat the prod
36、uct, material or substance still meets functionalspecifications or to fulfill a legal requirement).4.5 Information from the dose mapping is used to:4.5.1 Characterize the radiation process and assess thereproducibility of absorbed-dose values, which may be used aspart of operational qualification an
37、d performance qualification.4.5.2 Determine the spatial distribution of absorbed dosesand the zone(s) of maximum and minimum absorbed dosesthroughout a process load, which may consist of an actual orsimulated product.4.5.3 Establish the relationship between the dose at aroutine monitoring position a
38、nd the dose within the minimumand maximum dose zones established for a process load.4.5.4 Verify mathematical dose calculation methods. SeeASTM Guide E2232.4.5.5 Determine the effect of process interruptions on thedistribution of absorbed dose and the magnitude of the mini-mum and maximum doses.4.5.
39、6 Assess the impact on the distribution of absorbed doseand the magnitude of the minimum and maximum dosesresulting from the transition from one process load to anotherwhere changes, for example, in product density or productloading pattern may occur.5. Prerequisites5.1 Prerequisites to Dose Mapping
40、: Installation Qualifica-tion and Dosimetry System Calibration:5.1.1 Prior to performing dose mapping for irradiator op-erational qualification (OQ) and performance qualification(PQ), confirm that installation qualification (IQ) is complete.5.1.1.1 For electron beam and X-ray irradiation facilities,
41、IQ includes dosimetric testing to confirm the characteristics ofthe beam (electron energy, average beam current, and ifapplicable, scan width and scan uniformity). Refer to ISO/ASTM 51431, 51608, 51818, 51649 and ISO 11137-1.5.1.1.2 For gamma irradiation facilities, dosimetric testingis not required
42、 during IQ; however, the activity of the sourceand location of the individual components of the source shouldbe confirmed and documented. Refer to ISO/ASTM 51702 andISO 11137-1.5.1.2 Select an appropriate dosimetry system(s) for the dosemapping exercises. See 6.2.4.1 and ISO/ASTM 52628 forguidance.5
43、.2 Calibration of the Dosimetry System:5.2.1 Prior to use, the dosimetry system, consisting ofdosimeters measurement instruments and their associated ref-erence standards, and procedures for the systems use, shouldbe calibrated in accordance with the users documented pro-cedure that specifies detail
44、s of the calibration process andquality assurance requirements. Calibration methods are de-scribed in ISO/ASTM 51261.NOTE 3A dosimetry system calibration obtained using irradiationconditions different from the conditions of use may be used for relativedose measurement applications. For example, an i
45、rradiation facility mayperform a lab-based calibration with subsequent verification using refer-ence standard dosimeters under the conditions of use.While dose mappingat the irradiation facility may be performed using dose values from thelab-based calibration (prior to completing the verification ex
46、ercise) toassess the dose distribution and locations of minimum and maximumabsorbed dose, these dose measurements would be considered preliminary(i.e. relative) pending the outcome of the verification exercise.5.2.2 For the calibration of the instruments, and for theverification of instrument perfor
47、mance between calibrations,see ISO/ASTM 51261 or instrument-specific operatingmanuals, or both.6. Dose mapping6.1 Dose Mapping for Operational Qualification of theIrradiation Facility:6.1.1 As specified in ISO/ASTM Practices 51431, 51608,51649, 51702, and ISO 11137-1, perform irradiation facilitydos
48、e mapping to characterize the irradiator with respect to thedose distribution and reproducibility of absorbed dose delivery.This should be performed in accordance with a formal valida-tion program, and should cover the operational range that willbe used in the irradiation of products.6.1.2 Perform i
49、rradiation facility dose mapping by placingdosimeters in a number of process loads of reference materialthat fills the container to its design volume limits. The numberof process loads to be dose mapped should be large enough (3or more) to determine the variability of dose. For thoseirradiation facilities that vary operating parameters whichimpact dose distribution, dose mapping should be carried outover a range of selected operating parameters which cover theoperational limits to be used in the irradiation of products.6.1.2.1 Specific to Phot
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