ASTM E2381-04(2010)

Standard Guide for Dosimetry In Radiation Processing of Fluidized Beds and Fluid Streams (Withdrawn 2016)

SIGNIFICANCE AND USE
Dosimetric Techniques—The processes addressed here utilize a variety of techniques for the dynamic presentation of the product to the radiation source. This may involve gravitational flow or simple pneumatic transport about or past the radiation source. In the case of fluidized beds, the product may be presented to the radiation source while supported in a gaseous or liquid stream moving at relatively high velocities. This document provides a guide to the dosimetric techniques suitable for these processes.
Food Products—Food products may be treated with ionizing radiation, such as energetic electrons from accelerators or gamma rays from 60Co or 137Cs sources, or X-rays, for numerous purposes, including control of parasites and pathogenic microorganisms, insect disinfestation, growth and maturation inhibition, and shelf-life extension.  
Note 1—Food irradiation specifications usually include upper and lower limits of absorbed dose: a minimum to ensure the intended beneficial effect and a maximum to avoid product degradation. For a given application, one or both of these values may be prescribed by regulations that have been established on the basis of 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 irradiation of the food product. Once this capability is established, it may be necessary to monitor and record the dose range delivered to the product during each production run to verify compliance with the process specifications within a predetermined level of confidence.
Randomized Flow—In a stream of randomized flow; i.e. turbulent instead of laminar, variations occur which lead to a dose distribution for the particles entrained in the stream. The “idealized” maximum and minimum doses possible can be calculated based upon knowledge of the applied dose rate, the product dwell time in the irradiation cell and the product or bed thickness. The expe...
SCOPE
1.1 This guide describes several dosimetry systems and methods suitable for the documentation of the irradiation of product transported as fluid or in a fluidized bed.
1.2 The sources of penetrating ionizing radiation included in this guide are electron beams, X-rays (bremsstrahlung) and gamma rays.
1.3 Absorbed doses from 10 to 100,000 gray are considered, including applications such as disinfestation, disinfection, bioburden reduction, sterilization, crosslinking and graft modification of products, particularly powders and aggregates.
1.4 This guide does not purport to address the safety concerns, if any, associated with the use of fluidized beds and streams incorporating sources of ionizing radiation. It is the responsibility of the user of this guide to establish appropriate safety and health practices and to determine compliance with regulatory limitations prior to use.
WITHDRAWN RATIONALE
This guide describes several dosimetry systems and methods suitable for the documentation of the irradiation of product transported as fluid or in a fluidized bed.
Formerly under the jurisdiction of Committee E61 on Radiation Processing, this guide was withdrawn in June 2016. This standard is being withdrawn without replacement because to the committees’ knowledge it is not used in the industry anymore.

General Information

• Status: Withdrawn
• Publication Date: 30-Nov-2010
• Withdrawal Date: 10-Jul-2016
• ICS: 17.240 - Radiation measurements
• Technical Committee: E61 - Radiation Processing
• Drafting Committee: E61.04 - Specialty Application

Relations

• Replaces: ASTM E2381-04 - Standard Guide for Dosimetry In Radiation Processing of Fluidized Beds and Fluid Streams
• Effective Date: 01-Dec-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2381 − 04 (Reapproved2010)
Standard Guide for
Dosimetry In Radiation Processing of Fluidized Beds and
Fluid Streams
This standard is issued under the fixed designation E2381; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope F1355GuideforIrradiationofFreshAgriculturalProduceas
a Phytosanitary Treatment
1.1 This guide describes several dosimetry systems and
F1885Guide for Irradiation of Dried Spices, Herbs, and
methods suitable for the documentation of the irradiation of
Vegetable Seasonings to Control Pathogens and Other
product transported as fluid or in a fluidized bed.
Microorganisms
1.2 Thesourcesofpenetratingionizingradiationincludedin
2.2 ISO/ASTM Standards:
this guide are electron beams, X-rays (bremsstrahlung) and
51204 Standard Practice for Dosimetry in Gamma Irradia-
gamma rays.
tion Facilities for Food Processing
1.3 Absorbeddosesfrom10to100,000grayareconsidered, 51261Guide for Selection and Calibration of Dosimetry
Systems for Radiation Processing
including applications such as disinfestation, disinfection,
bioburdenreduction,sterilization,crosslinkingandgraftmodi- 51275Practice for Use of a Radiochromic Film Dosimetry
System
fication of products, particularly powders and aggregates.
51310Practice for the Use of a Radiochromic Optical
1.4 This guide does not purport to address the safety
Waveguide Dosimetry Systems
concerns, if any, associated with the use of fluidized beds and
51400 Practice for Characterization and Performance of a
streams incorporating sources of ionizing radiation. It is the
High-Dose Radiation Dosimetry Calibration Laboratory
responsibility of the user of this guide to establish appropriate
51431 Practice for Dosimetry in Electron and X-Ray
safety and health practices and to determine compliance with
(Bremsstrahlung) Irradiation Facilities for Food Process-
regulatory limitations prior to use.
ing
51538Practice for Use of the Ethanol-Chlorobenzene Do-
2. Referenced Documents
simetry System
2.1 ASTM Standards:
51540PracticeforUseofaRadiochromicLiquidDosimetry
E170Terminology Relating to Radiation Measurements and
System
Dosimetry
51607 Practice for Use of the Alanine-EPR Dosimetry
E666Practice for CalculatingAbsorbed Dose From Gamma
System
or X Radiation
51608PracticeforDosimetryinanX-Ray(Bremsstrahlung)
E1026Practice for Using the Fricke Dosimetry System
Facility for Radiation Processing
E2232Guide for Selection and Use of Mathematical Meth-
51649Practice for Dosimetry in an Electron Beam Facility
ods for CalculatingAbsorbed Dose in Radiation Process-
forRadiationProcessingatEnergiesbetween300keVand
ing Applications
25 MeV
51702Practice for Dosimetry in a Gamma Irradiation Facil-
This guide is under the jurisdiction of ASTM Committee E61 on Radiation
ity for Radiation Processing
Processing and is the direct responsibility of Subcommittee E61.04 on Specialty
51707Guide for Estimating Uncertainties in Dosimetry for
Application.
Radiation Processing
Current edition approved Dec. 1, 2010. Published January 2011. Originally
51818Practice for Dosimetry in an Electron Beam Facility
approved in 2004. Last previous edition approved in 2004 as E2381–04. DOI:
10.1520/E2381-04R10.
for Radiation Processing at Energies Between 80 and 300
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
keV
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
51956Practice forApplication of Thermoluminescence Do-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. simetry (TLD) Systems for Radiation Processing
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2381 − 04 (2010)
2.3 International Commission on Radiation Units and Mea- 3.1.6 bed thickness—total thickness of the fluidized bed,
surements Reports which includes the product being processed and the carrier
-2
ICRUReport14 RadiationDosimetry:X-RaysandGamma medium, both normalized by density. The SI unit is kg. m .
-2
RayswithMaximumPhotonEnergiesBetween0.6and50
3.1.6.1 Discussion—thickness is typically quoted in g. m
MeV
due to its numerical equivalence to thickness in micrometers
ICRUReport17 RadiationDosimetry:X-RaysGeneratedat
for unit density matter.
Potentials of 5 to 150 kV
3.1.7 Bremsstrahlung—broad-spectrum electromagnetic ra-
ICRU Report 30 International Comparison of Radiological
diation (X-rays) emitted when an energetic electron is influ-
Units and Measurements: Quantitative Concepts and Do-
enced by strong electric field or magnetic field such as that in
simetry in Radiobiology
the vicinity of an atomic nucleus.
ICRU Report 34 The Dosimetry of Pulsed Radiation
3.1.7.1 Discussion—bremsstrahlung is produced when an
ICRUReport35 RadiationDosimetry:ElectronBeamswith
electron beam strikes any material (converter). The
Energies Between 1 and 50 MeV
bremsstrahlung spectrum depends on the electron energy, the
ICRU Report 37 Stopping Powers for Electrons and Posi-
converter material and its thickness, and contains energies up
trons
to the maximum kinetic energy of the incident electrons (see
ICRU Report 60 Fundamental Quantities and Units for
ISO/ASTM Practice 51608).
Ionizing Radiation
3.1.8 calibration curve—graphical representation of the do-
2.4 National Committee for Radiation Protection
simetry system’s response function.
NCRP Report 69Dosimetry of X-Ray and Gamma-Ray
BeamsforRadiationTherapyintheEnergyRange10keV 3.1.9 depth-dose distribution—variation of absorbed dose
to 50 MeV with depth from the incident surface of a material exposed to
a given radiation.
3. Terminology
3.1.10 dose uniformity ratio—ratio of the maximum to the
3.1 Definitions:
minimumabsorbeddosewithintheirradiatedobjectorprocess
3.1.1 absorbed dose D—quantity of ionizing radiation en-
stream.
ergyimpartedperunitmassofaspecifiedmaterial.TheSIunit
3.1.10.1 Discussion—the concept is also referred to as the
of absorbed dose is the gray (Gy), where 1 gray is equivalent
max/min dose ratio and is significantly influenced by the
to the absorption of 1 joule per kilogram of the specified
turbulence of the product flow.
-1
material (1 Gy=1Jkg ). The mathematical relationship for
3.1.11 dosimeter—device that, when irradiated, exhibits a
dose is the quotient of dε by dm, where dε is the mean
quantifiable change in some property of the device which can
incremental energy imparted by ionizing radiation to matter of
be related to absorbed dose in a given material using appro-
incremental mass dm (see ICRU 60).
priate analytical instrumentation and techniques.
3.1.1.1 Discussion—discontinued unit for absorbed dose is
3.1.12 dosimeter response—reproducible, quantifiable ra-
therad(1rad=0.01Gy).Absorbeddoseissometimesreferred
diation effect on a dosimeter produced by a given absorbed
to simply as dose.
dose.
3.1.2 absorbed dose mapping—measurement of absorbed
3.1.13 dosimetry system—system used for determining ab-
dose within a process stream using dosimeters transported at
specified locations to produce a one or two-dimensional sorbed dose, consisting of dosimeters, measurement instru-
mentsandtheirassociatedreferencestandards,andprocedures
distribution of absorbed dose, thus rendering a map of
absorbed-dose values. for the system’s use.
3.1.3 absorbed dose rate—absorbed dose in a material per 3.1.14 electron energy—kinetic energy of the accelerated
incremental time interval, i.e. the quotient of dD by dt (see
electrons. The electron energy at the product is equal to its
-1
ICRU 60) Unit: Gy s accelerated energy in vacuum less its energy losses in the
3.1.3.1 Discussion—absorbed dose rate can be specified in accelerator’s window and the air gap separating the product
termsoftheaveragevalueofdDbydtoverlong-timeintervals,
and the window.
-1 -1
for example, in units of Gy min or Gy h
3.1.15 electron fluence—amount of electronic charge tra-
3.1.4 areal density—thickness of an object normalized by
versing a unit area of the target, usually expressed in micro-
-2
density. The SI unit is kg m .
coulombs per square centimeter. It is the integral of flux over
3.1.4.1 Discussion—the abbreviation gsm is also used in
total exposure time
referring to areal density in grams per square meter in some
3.1.16 fluidized bed or stream—meansbywhichtheproduct
technical literature.
istransportedandpresentedtotheradiationsource.Thecarrier
3.1.5 bed control—technique used for determining the flu-
medium may be gaseous or liquid. The product distribution
idized bed thickness and maintaining it between the limits
within the carrier medium may not be uniform.
required for controlled application of the process.
3.1.17 primary-standard dosimeter—dosimeter of the high-
est metrological quality, established and maintained as an
absorbeddosestandardbyanationalorinternationalstandards
Available from the International Commission on Radiation Units and
Measurements, 7910 Woodmont Avenue, Suite 800, Bethesda, MD, 20814,USA organization.
E2381 − 04 (2010)
3.1.18 quality assurance—all systematic actions necessary inASTM Terminology E170. Definitions in E170 are compat-
to provide adequate confidence that a calibration, iblewithICRU60;thatdocument,therefore,maybeusedasan
measurement, or process is performed to a predefined level of
alternative reference.
quality.
4. Significance and Use
3.1.19 real time dose monitor—instrument capable of con-
tinuously providing measured data on dose delivered during
4.1 Dosimetric Techniques—The processes addressed here
processing.
utilize a variety of techniques for the dynamic presentation of
the product to the radiation source. This may involve gravita-
3.1.20 reference-standard dosimeter—dosimeter of high
metrological quality, used as a standard to provide measure- tional flow or simple pneumatic transport about or past the
ments traceable to and consistent with measurements made radiationsource.Inthecaseoffluidizedbeds,theproductmay
using primary standard dosimeters. be presented to the radiation source while supported in a
gaseous or liquid stream moving at relatively high velocities.
3.1.21 response function—mathematical representation of
This document provides a guide to the dosimetric techniques
therelationshipbetweendosimeterresponseandabsorbeddose
suitable for these processes.
for a given dosimetry system.
4.2 Food Products—Food products may be treated with
3.1.22 routine dosimeter—dosimeter calibrated against a
primary, reference, or transfer standard dosimeter and used for ionizing radiation, such as energetic electrons from accelera-
60 137
torsorgammaraysfrom Coor Cssources,orX-rays,for
routine absorbed dose measurement.
numerous purposes, including control of parasites and patho-
3.1.23 self-shielded system—product transport-irradiation
genic microorganisms, insect disinfestation, growth and matu-
unit with integral shielding.
ration inhibition, and shelf-life extension.
3.1.23.1 Discussion—this type of conformal shielding is
typically used at lower radiation energies where rather thin
NOTE 1—Food irradiation specifications usually include upper and
layers of lead can protect the surrounding environment from
lower limits of absorbed dose: a minimum to ensure the intended
beneficialeffectandamaximumtoavoidproductdegradation.Foragiven
virtually all of the radiation generated by the irradiator.
application, one or both of these values may be prescribed by regulations
3.1.24 simulated product—mass of material with attenua-
that have been established on the basis of available scientific data.
tion and scattering properties similar to those of the product, Therefore, it is necessary to determine the capability of an irradiation
facilitytoprocesswithintheseabsorbed-doselimitspriortotheirradiation
material or substance to be irradiated, sometimes called a
of the food product. Once this capability is established, it may be
dummy product.
necessary to monitor and record the dose range delivered to the product
3.1.25 surface dose—absorbed dose at the surface of the
during each production run to verify compliance with the process
specifications within a predetermined level of confidence.
product.
3.1.25.1 Discussion—This definition becomes particularly
4.3 Randomized Flow—Inastreamofrandomizedflow;i.e.
important where low energy radiation is used to treat only the
turbulent instead of laminar, variations occur which lead to a
surface of particulates.
dose distribution for the particles entrained in the stream. The
“idealized” maximum and minimum doses possible can be
3.1.26 target dose—absorbed dose delivered to the surface
of the bed which will produce the required absorbed dose calculated based upon knowledge of the applied dose rate, the
distribution within the remainder of the product irradiated in productdwelltimeintheirradiationcellandtheproductorbed
the fluidized bed. thickness.Theexperimentallydeterminedmaximumandmini-
mum doses delivered to each particle, should not be confused
3.1.27 traceability—ability to demonstrate by means of an
with these idealized dose limits.
unbroken chain of comparisons that a measurement is in
agreement within acceptable limits of uncertainty with compa-
4.4 Treatment range—The location of the product (or of the
rable nationally or internationally recognized standards.
dosimeter) in the fluidized bed or stream will determine its
absorbed dose during passage through the radiation field. The
3.1.28 transfer-standard dosimeter—dosimeter, often a ref-
experimentaldosemeasurementsinthefluidizedbedorstream
erence standard dosimeter, suitable for transport between
will define the range of product dose. The desired effect
different locations, used to compare absorbed-dose measure-
ments. imparted to the product by irradiation will then be based upon
thisrangeofproductdoseandnotuponmaximumorminimum
3.1.29 uncertainty—parameter associated with the result of
dose.
anymeasurementthatcharacterizesthedispersionofthevalues
that could reasonably be attributed to the measured or derived
NOTE 2—In situations where a randomized mixing within the fluidized
quantity.
bed occurs with the intention that the particles or fluid elements pass
through several radiation zones and accumulate a total dose with different
3.1.30 validation—establishment of documented evidence,
dose rates, maximum and minimum dose values are difficult to determine
which provides a high degree of assurance that a specified
andmustbebasedontheresultsfortheexperimentaldosimetryirradiated
process will consistently produce a product meetin
...