1、BRITISH STANDARD BS ISO 15554:1998 Practice for dosimetry ingamma irradiation facilities for food processing ICS 17.240; 67.020BS ISO 15554:1998 This British Standard, having been prepared under the directionof the Engineering SectorCommittee, was publishedunder the authority ofthe Standards Committ
2、ee andcomes into effect on 15 August1998 BSI 03-2000 ISBN 0 580 32913 5 National foreword This British Standard reproduces verbatim ISO15554:1998 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee NCE/2, Health physics instrume
3、ntation, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and pr
4、omulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the
5、 section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applica
6、tion. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages 1 to 8 and abackcover. This standard has been updated (see copyr
7、ight date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBS ISO 15554:1998 BSI 03-2000 i Contents Page National foreword Inside front cover Foreword iii Text of ISO 15554 1i
8、i blankBSISO15554:1998 ii BSI 03-2000 Contents Foreword iii 1 Scope 1 2 Referenced Documents 1 3 Terminology 2 4 Significance and Use 3 5 Radiation Source Characteristics 3 6 Types of Facilities 3 7 Dosimetry Systems 3 8 Installation Qualification 4 9 Process Qualification 5 10 Routine Production Pr
9、ocessing 6 11 Certification 7 12 Precision and Bias 7 13 Keywords 7 Figure 1 An Example of the Maximum and Minimum Absorbed-Dose Locations in a Typical Product (17) 5 References 8BSISO15554:1998 BSI 03-2000 iii Foreword ISO (the International Organization for Standardization) is a worldwide federati
10、on of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO 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
11、. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with theInternational Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technic
12、al committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO15554 was prepared by the American Society forTesting and Materials (ASTM) Subcommittee E10.01 (as E1
13、204-93) and wasadopted, under a special “fast-track procedure”, by Technical Committee ISO/TC 85, Nuclear energy, in parallel with its approval by the ISO member bodies. A new ISO/TC 85 Working Group WG 3, High-level dosimetry for radiation processing, was formed to review the voting comments from t
14、he ISO “Fast-track procedure” and to maintain these standards. The USA holds the convenership of this working group. International Standard ISO15554 is one of20 standards developed and published by ASTM. The20 fast-tracked standards and their associated ASTM designations are listed below: ISO Design
15、ation ASTM Designation Title 15554 E 1204-93 Practice for dosimetry in gamma irradiation facilities for food processing 15555 E 1205-93 Practice for use of a ceric-cerous sulfate dosimetry system 15556 E 1261-94 Guide for selection and calibration of dosimetry systems for radiation processing 15557
16、E 1275-93 Practice for use of a radiochromic film dosimetry 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 system 15560 E 1400-95a Practice for characterization and performance of a h
17、igh-dose radiation dosimetry calibration laboratory 15561 E 1401-96 Practice for use of a dichromate dosimetry system 15562 E 1431-91 Practice for dosimetry in electron and bremsstrahlung irradiation facilities for food processing 15563 E 1538-93 Practice for use of the ethanol-chlorobenzene dosimet
18、ry system 15564 E 1539-93 Guide for use of radiation-sensitive indicators 15565 E 1540-93 Practice for use of a radiochromic liquid dosimetry system 15566 E 1607-94 Practice for use of the alanine-EPR dosimetry systemBSISO15554:1998 iv BSI 03-2000 ISO Designation ASTM Designation Title 15567 E 1608-
19、94 Practice for dosimetry in an X-ray (bremsstrahlung) facility for radiation processing 15568 E 1631-96 Practice for use of calorimetric dosimetry systems for electron beam dose measurements and dosimeter calibrations 15569 E 1649-94 Practice for dosimetry in an electron-beam facility for radiation
20、 processing at energies between300keV and 25 MeV 15570 E 1650-94 Practice for use of cellulose acetate dosimetry system 15571 E 1702-95 Practice for dosimetry in a gamma irradiation facility for radiation processing 15572 E 1707-95 Guide for estimating uncertainties in dosimetry for radiation proces
21、sing 15573 E 1818-96 Practice for dosimetry in an electron-beam facility for radiation processing at energies between80keV and300keVBS ISO 15554:1998 BSI 03-2000 1 1 Scope 1.1 This practice outlines dosimetric procedures to be followed in irradiator characterization, process qualification, and routi
22、ne processing of food with ionizing radiation from isotopic gamma sources to ensure that all product has been treated within a predetermined range of absorbed dose. Other procedures related to irradiator characterization, process qualification, and routine processing that may influence absorbed dose
23、 in the product are also discussed. Information about effective or regulatory dose limits for food products is not within the scope of this practice (see Guides F1355 and F1356). NOTE 1Dosimetry is only one component of a total quality assurance program for adherence to good manufacturing practices
24、used in the production of safe and wholesome food. NOTE 2Practice E1431 describes dosimetric procedures for electron beam and bremsstrahlung (X-ray) irradiation facilities for food processing. 1.2 For guidance in the selection, calibration, and use of specific dosimeters, and interpretation of absor
25、bed dose in the product from dosimetry measurements, see Guide E1261; Practices E666, E668, E1026, E1205, E1275, E1276, E1310, and E1401. For discussion of radiation dosimetry for gamma rays and X-rays see ICRU Report14. 1.3 This standard does not purport to address all of the safety problems, if an
26、y, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2 Referenced Documents 2.1 ASTM Standards: E 170, Terminology Relating to Radiation Measureme
27、nts and Dosimetry 1) . E 275, Practice for Describing and Measuring Performance of Ultraviolet, Visible, and Near Infrared Spectrophotometers 2) . E 666, Practice for Calculating Absorbed Dose from Gamma or X Radiation 1) . E 668, Practice for Application of Thermoluminescence-Dosimetry (TLD) System
28、s for Determining Absorbed Dose in Radiation-Hardness Testing of Electronic Devices 1) . E 925, Practice for the Periodic Calibration of Narrow Band-Pass Spectrophotometers 2) . E 958, Practice for Measuring Practical Spectral Band-width of Ultraviolet-Visible Spectrophotometers 2) . E 1026, Practic
29、e for Using the Fricke Reference Standard Dosimetry System 1) . E 1205, Practice for Use of a Ceric-Cerous Sulfate Dosimetry System 1) . E 1261, Guide for Selection and Application of Dosimetry Systems for Radiation Processing ofFood 1) . E 1275, Practice for Use of a Radiochromic Film Dosimetry Sys
30、tem 1) . E 1276, Practice for Use of a Polymethylmethacrylate Dosimetry System 1) . E 1310, Practice for Use of a Radiochromic Optical Waveguide Dosimetry System 1) . E 1400, Practice for Characterization and Performance of a High-Dose Gamma-Radiation Dosimetry Calibration Laboratory 1) . E 1401, Pr
31、actice for Use of a Dichromate Dosimetry System 1) . E 1431, Practice for Dosimetry in Electron Beam and Bremsstrahlung Irradiation Facilities for Food Processing 1) . E 1538, Practice for Use of an Ethanol-Chlorobenzene Dosimetry System 1) . E 1539, Guide for the Use of Radiation-Sensitive Indicato
32、rs 1) . E 1540, Practice for the Use of a Radiochromic Liquid Dosimetry System 1) . F 1355, Guide for the Irradiation of Fresh Fruits for Insect Disinfestation as a Quarantine Treatment 3) . F 1356, Guide for the Irradiation of Fresh and Frozen Red Meats and Poultry (to Control Pathogens) 3) . 2.2 I
33、nternational Commission on Radiation Units and Measurements (ICRU) Reports: ICRU Report 14 Radiation Dosimetry: X-Rays and Gamma Rays with Maximum Photon Energies Between 0.6 and 50 MeV 4) . ICRU Report 33 Radiation Quantities and Units 4) . 1) Annual Book of ASTM Standards, Vol 12.02. 2) Annual Boo
34、k of ASTM Standards, Vol 14.01. 3) Annual Book of ASTM Standards, Vol 15.07. 4) Available from the International Commission on Radiation Units and Measurements, 7910 Woodmont Ave., Suite 800, Bethesda, MD 20814.BS ISO 15554:1998 2 BSI 03-2000 2.3 Codex Alimentarius Commission Reports: CAC Vol XV (19
35、84): Codex General Standard for Irradiated Foods and Recommended International Code of Practice for the Operation of Radiation Facilities Used for the Treatment of Foods 5) . 3 Terminology 3.1 Definitions Other terms used in this practice, in addition to those in3.1.1 and 3.1.2, are defined in Termi
36、nology E170 andin ICRU Report33. 3.1.1 absorbed dose, D quotient of d(e) by dm, where d(e) is the mean energy imparted by ionizing radiation to matter ofmass dm (see ICRU Report33) D = d(e)/dm the special name for the unit of absorbed dose is the gray (Gy): 1 Gy = 1 Jkg 1 formerly, the special unit
37、for absorbed dose was therad: 1 rad = 10 2Jkg 1= 10 2Gy 3.1.2 absorbed-dose mapping measurement of the absorbed-dose distribution in an irradiation unit through the use of dosimeters placed at specified locations within the irradiation unit 3.2 Descriptions of Terms Specific to This Standard: 3.2.1
38、compensating dummy consists of material that matches the density and gamma attenuation characteristics of the actual product to the extent required to meet prescribed minimum or maximum absorbed doses. It is used during routine production runs within a partially filled irradiation unit or at the beg
39、inning and end of a production run to compensate for the absence of product. See also simulated product 3.2.2 irradiation time total time during which an irradiation unit is exposed to radiation 3.2.3 irradiation unit one or more containers of product, collectively transported through the irradiator
40、 as a whole, for example, box, tote, pallet, or carrier. This term is not relevant to bulk-flow processing 3.2.4 primary standard dosimeter a dosimeter that has the highest metrological quality in the field of radiation dosimetry and is recognized as such on a national or international basis 3.2.5 p
41、roduction run a series of irradiation units containing the same food product irradiated sequentially to nominally the same absorbed dose 3.2.6 reference standard dosimeter a dosimeter, generally of the highest metrological quality available at a facility, that is traceable to national primary standa
42、rds 3.2.7 routine dosimeter a dosimeter calibrated against a primary, reference, or transfer standard dosimeter and used routinely to make dosimetry measurements 3.2.8 simulated product consists of material that closely matches the density and gamma attenuation characteristics of the foods of intere
43、st. It is used as a substitute for the actual product during irradiator characterization 3.2.9 transfer standard dosimeter a dosimeter prepared in a stable and rugged form, used by a nationally recognized standards calibration laboratory as an intermediary to compare absorbed-dose rates in radiation
44、 environments and check the calibration of routine dosimeters 5) Available from the Joint FAO/WHO Food Standards Program, Joint Office, Food and Agriculture Organization of the United Nations, Via Della Terme de Caracalla, 00100 Rome, Italy.BS ISO 15554:1998 BSI 03-2000 3 4 Significance and Use 4.1
45、Food products may be treated with ionizing radiation, such as gamma rays from 60 Co or 137 Cs sources, for numerous purposes, including parasite and pathogen control, insect disinfestation, growth and maturation inhibition, and shelf-life extension. Food irradiation specifications usually include a
46、pair of absorbed-dose limits. For a given application, one or both of these values may be prescribed by regulations based on available scientific data. Therefore, it is necessary to determine the capability of an irradiation facility to process within these absorbed-dose limits prior to the irradiat
47、ion of the food product. Once this capability is established, it is necessary to monitor and record the absorbed dose during each production run to verify compliance with the process specifications within a predetermined level of confidence. NOTE 3The Codex Alimentarius Commission (1) 6)uses the ter
48、m “overall average absorbed dose” in discussing broad concepts such as the wholesomeness of foods irradiated to an overall average absorbed dose of less than10kGy. The overall average dose should not, however, be used in place of minimum or maximum absorbed doses for specific applications. The CAC c
49、onfirms this in the following statement from CAC/RCP 19-1979, Annex A: “(T)he design of the facility and the operational parameters have to take into account minimum and maximum dose values required by the process.” 4.2 Some food products are processed in the chilled or frozen state. Therefore, it is necessary to confirm that the dosimeters used for routine monitoring are useable at low temperature and that the dosimeter temperature during irradiation is sufficiently stable to allow correction for temperature effects on the dosimeter response. 4.3 For more det
