RECOMMENDED
INTERNATIONAL CODE OF PRACTICE FOR RADIATION PROCESSING OF FOOD
(CAC/RCP
19-1979, Rev. 2-2003)
INTRODUCTION
Food
irradiation is the processing of food products by ionizing radiation in order
to, among other things, control foodborne pathogens, reduce microbial load
and insect infestation, inhibit the germination of root crops, and extend
the durable life of perishable produce. Many countries are using industrial
irradiators for processing of food products for commercial purposes.
The regulatory
control of food irradiation should take into consideration the Codex General
Standard for Irradiated Foods (CODEX-STAN 106-1983, Rev. 1-2003) and this
Code. The purpose of regulatory control of irradiated food products should
be:
a) to ensure that
radiation processing of food products is implemented safely and correctly,
in accordance with all relevant Codex standards and codes of hygienic practice;
b) to establish
a system of documentation to accompany irradiated food products, so that the
fact of irradiation can be taken into account during subsequent handling,
storage and marketing; and
c) to ensure that
irradiated food products that enter into international trade conform to acceptable
standards of radiation processing and are correctly labelled.
The purpose of
this Code is to provide principles for the processing of food products with
ionizing radiation that are consistent with relevant Codex Standards and codes
of hygienic practice. Food irradiation may be incorporated as part of a HACCP-plan
where applicable; but a HACCP-plan is not required for the use of radiation
processing of food processed for purposes other than for food safety. The
provisions of this Code will provide guidance to the radiation processor to
apply the Hazard Analysis and Critical Control Point (HACCP) system, as recommended
in the Recommended International Code of Practice General Principles of
Food Hygiene (CAC/RCP 1-1969, Rev 3-1997, Amd. 1-1999), where applicable
for food safety purposes, to foods processed by ionizing radiation.
1. OBJECTIVES
2. SCOPE,
USE and DEFINITIONS
2.1 Scope
This Code is concerned
with food products processed by gamma rays, X-rays or accelerated electrons
for the purpose of, among other things, control of foodborne pathogens, reduction
of microbial load and insect infestation, inhibition of the germination of
root crops, and extension of durable life for perishable foods.
This Code covers
the requirements of the irradiation process in a facility; it also considers
other aspects of the process as primary production and/or harvesting, post-harvest
treatment, storage and shipment, packaging, irradiation, labelling, post-irradiation
storage and handling, and training.1
1 Codes of good
irradiation practice, compilations of technical data for the authorization
and control of the irradiation of several food classes and also training manuals
for facility operators and control officials have been produced by the International
Consultative Group on Food Irradiation (ICGFI), available through the International
Atomic Energy Agency, PO Box 100, A-1400 Vienna, Austria.
2.2 Use
The
Recommended International Code of Practice - General Principles of Food
Hygiene (CAC/RCP 1- 1969, Rev 3-1997, Amd. 1-1999) and its annex on application
of the HACCP system, as well as other relevant Codex Standards and codes of
hygienic practice should be used with this document. Of particular relevance
are the Codex General Standard for Irradiated Foods (CODEX-STAN 106-1983
- Rev.1-2003) and the General Standard for the Labelling of Pre-Packaged
Foods (CODEX-STAN 1-1985, Rev 1 - 1991).
2.3 Definitions
For
purposes of this Code, the terms below are defined as follows:
Food Irradiation: Processing of food products by ionizing radiation,
specifically gamma rays, X-rays or accelerated electrons as specified in the
Codex General Standard for Irradiated Foods.
Irradiated Food: Food products processed by ionizing radiation in accordance
with the Codex General Standard for Irradiated Foods. Such food is subject
to all relevant standards, codes and regulations applicable to the nonirradiated
counterpart.
Dosimetry: The measurement of the absorbed dose of radiation at
a particular point in a given absorbing
medium.
Dose
(absorbed): The absorbed dose, sometimes referred to simply as
'dose', is the amount of energy absorbed per unit mass of irradiated food
product.
Dose
Uniformity Ratio: The ratio of maximum to minimum absorbed dose in the
production lot.
Dose
Distribution: The spatial variation in absorbed dose throughout the production
lot with extreme values being the maximum absorbed dose and the minimum absorbed
dose.
Dose Limit: The minimum or maximum radiation dose absorbed by a food
product prescribed in regulations as required for technological reasons. Such
dose limits are expressed as ranges or as single lower or upper values (i.e.,
no part of the food product shall absorb less than or more than a specified
amount).
3.
PRE-IRRADIATION TREATMENT
3.1
Primary production and/or harvesting
3.2
Handling, storage and transport
The
intent to process food products by irradiation poses no unique requirements
regarding handling, storage and transport of the food products prior to and
subsequent to irradiation. All stages of the processing, i.e., pre-irradiation,
irradiation and post-irradiation, should be in accordance with good manufacturing
practices to maximize quality, to minimize contamination, and, if packaged,
to maintain package integrity.
Radiation
is applied to food products in forms in which they are normally prepared for
processing, commercially traded or otherwise used. Food intended for radiation
processing should conform to handling,storage and transport requirements of
the Codex General Principles of Food Hygiene as well as relevant Codex standards
and codes of practice for specific food products.
4. PACKAGING
In general, in
order to avoid contamination or infestation after irradiation, food products
should be packaged in materials that provide an effective barrier to re-contamination
and re-infestation. Packaging must also meet the requirements of the importing
country.
The size and shape
of containers that may be used for irradiation are determined, in part, by
the operating characteristics of the irradiation facility. These characteristics
include the product transport systems and the irradiation source, as they
affect the dose distribution within the container.
5. ESTABLISHMENT:
DESIGN, FACILITIES and CONTROL
Authorization
of a facility to irradiate food is granting approval to a facility licensed
for radiation processing in general to irradiate food products. Authorization
may be general in nature or issued for specific classes or groups of food
products. Facilities which carry out irradiation of food products should meet
appropriate standards of occupational safety and good hygiene conditions,
including:
- Regulations
regarding design, construction and operation of radiation facilities
- General Principles
of Food Hygiene
- General Standard
for Irradiated Foods and this Code.
5.1 Design
and layout
This section is
concerned with the areas in which food products are stored and irradiated.
Prevention of contamination requires that all measures be taken to avoid direct
or indirect contact of the food product with sources of potential contamination
and to minimize growth of microorganisms.
Irradiation establishments
are laid out to provide storage for irradiated and non-irradiated food products
(under ambient, refrigerated and/or freezing temperature conditions), an irradiator,
and the normal accommodation and infrastructure for staff and plant services
including record maintenance. In order to achieve inventory control there
should be provision in both the design and operation of the establishment
to keep irradiated and non-irradiated food products separate. This separation
can be accomplished by controlled singledirection movement of the food products
through the plant and by separated storage areas for irradiated and nonirradiated
food products.
Radiation facilities
must be designed to provide an absorbed dose in the food product within minimum
and maximum limits in accordance with process specifications and government
regulatory requirements. For conomic and technical reasons (e.g. maintaining
product quality), various techniques are used to minimize the ratio, which
is termed the dose uniformity ratio.
The following
factors largely govern the selection of irradiator design:
a) Means of transporting
food products: The mechanical design of the irradiation and transport systems,
including the source-to-product geometry in a given process, as required by
the form of the product, e.g. bulk or packaged, and its properties.
b) Range of doses:
The range of doses needed to process a wide variety of products for various
applications.
c) Throughput:
The amount of product to be processed within a defined period of time.
d)
Reliability: The property of providing correct performance as needed.
e) Safety-systems:
The systems intended to protect operating personnel from hazards posed by
radiation.
f) Compliance:
The adherence to good manufacturing practices and relevant government regulations.
g) Capital and
operational costs: The basic economic considerations necessary for sustainable
operation.
5.2 Radiation
sources
As described in
the Codex General Standard for Irradiated Foods, the following sources
of ionizing radiation may be used in food irradiation:
a)
Gamma rays from radionuclides 60Co or 137Cs;
b) X-rays generated
from machine sources operated at or below an energy level of 5 MeV; and
c) Electrons generated
from machine sources operated at or below an energy level of 10 MeV.
5.3 Control
of operation
5.3.1
Legislation
Food processing
establishments are constructed and operated in accordance with regulatory
requirements in order to ensure safety of the processed foods for consumption
and occupational safety of the plant personnel and the environment. A food
irradiation facility, like any other food processing plant, is also subject
to such regulation and should be designed, constructed and operated in compliance
with relevant regulations.
5.3.2
Requirements for staff
The staff at an
irradiation facility is subject to relevant sections of the Recommended
International Code of Practice General Principles of Food Hygiene (CAC/RCP
1-1969, Rev 3-1997, Amd. 1-1999) for personal hygiene recommendations and
to the General Standard for Irradiated Foods for recommendations regarding
the need for an adequate, trained and competent personnel.2
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2 Training manuals
for facility operators and control officials have been produced by ICGFI,
available through the International Atomic Energy Agency, PO Box 100, A-1400
Vienna, Austria. ICGFI also, through its FIPCOS, provides such training.
5.3.3
Requirements for process control
5.3.4
Control of applied dose
The
effectiveness of the irradiation process depends on proper application of
the dose and its measurement. Dose distribution measurements should be carried
out to characterize the process for each food product; and thereafter dosimeters
should be used routinely to monitor correct execution of the process in accordance
with internationally accepted procedures.3
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3 Such procedures
are specified, for example, by the American Society for Testing and Materials
(ASTM) in their annual handbooks.
5.3.5
Product and inventory control
An adequate system
should be in place so that specific consignments of food products can be traced
back both to the irradiation facility and the source from which they were
received for processing.
Plant design and
administrative procedures should ensure that it is impossible to mix irradiated
and nonirradiated food products. Incoming products should be logged and given
a code number to identify the packages at each step in its path through the
irradiation plant. All relevant parameters such as date, time, source strength,
minimum and maximum dose, temperature, etc. should be logged against the code
number of the product. It is not possible to distinguish irradiated from non-irradiated
product by visual inspection. Therefore, it is essential that appropriate
means, such as physical barriers, be employed for keeping the irradiated and
nonirradiated product separate. Affixing colour change indicator label on
each package, where applicable, provides another means of distinguishing irradiated
and non-irradiated product.
6. IRRADIATION
6.1 General
Refer to the Codex
General Standard for Irradiated Foods (CODEX-STAN 106-1983, Rev. 1-2003).
6.2 Process
determination
It is important
that all steps in the determination of process procedures are documented to:
a) ensure that
the application of the process complies with relevant regulatory requirements;
b) establish a
clear statement for the technological objectives of the process;
c) estimate the
dose range to be applied to achieve the technological objective based on appropriate
knowledge of the food product;
d) demonstrate
that irradiation of test samples has been carried out to confirm the estimated
dose range under practical production conditions;
e) ensure that
it is possible to meet the technological requirements, e.g. dose range
and effectiveness of treatment, under practical production conditions; and
f) establish the
process parameters under practical production conditions.
6.3 Dosimetry
Successful radiation
processing practice depends on the ability of the processor to measure the
absorbed dose delivered to each point in the food product and in the production
lot.
Various techniques
for dosimetry pertinent to radionuclide and machine sources are available
for measuring absorbed dose in a quantitative manner. Relevant ISO/ASTM Standard
Practices and Guides for dosimety in food irradiation facilities have been
developed and should be consulted.4
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4
ISO/ASTM 51204 – Standard Practice or Dosimetry in Gamma Irradiation Facilities
for Food Processing; ISO/ASTM 51431 – Standard Practice for Dosimetry in Electron
and Bremsstrahlung Irradiation Facilities for Food Processing; ISO/ASTM 51261
– Standard Guide for Selection and Calibration of Dosimetry Systems for Radiation
Processing.
In order to implement
these irradiation practices, facilities should be adequately staffed by competent
personnel trained in dosimetry and its application in radiation processing.
The calibration
of the dosimetry system used in radiation processing should be traceable (i.e.,
calibrated) to national and international standards.
6.4 Dosimetry
systems
Dosimeters
are devices that are capable of providing a quantitative and reproducible
measurement ofdose through a change in one or more of the physical properties
of the dosimeters in response to the exposure to ionizing radiation energy.
A dosimetry system consists of dosimeters, measurement instruments and their
associated reference standards, and procedures for the system's use. Selection
of appropriate dosimetry system for radiation processing of food will depend
on a variety of factors, including the dose range needed to achieve a particular
technological objective, cost, availability, and ease of use. A variety of
dosimetry systems are available.5
5ISO/ASTM
51261 – Standard Guide for Selection and Calibration of Dosimetry Systems
for Radiation Processing
6.5 Dosimetry
and process control
In
food irradiation, the key quantity that governs the process is the absorbed
dose. It is influenced by various parameters, such as: radiation source type,
strength and geometry; conveyor speed or dwell time; food product density
and loading configuration; and carrier size and shape.6 Their overall
influence on dose distribution must be taken into account to ensure that the
intended technological objective is achieved throughout the production lot.
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6
ISO/ASTM 51204 – Standard Practice or Dosimetry in Gamma Irradiation
Facilities for Food Processing and ISO/ASTM 51431 – Standard Practice for
Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing
The
application of radiation processing is mainly governed by the minimum absorbed
dose achieved in the dose distribution within a given product. If the required
minimum is not applied, the intended technical effect may not be achieved
(e.g. sprout inhibition, pathogen reduction). There are also situations where
the application of too high a dose would impair the quality of the treated
food (e.g. off flavours or odours). 7
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7
Codes of good irradiation practice and compilations of technical data for
the authorization and control of the irradiation of several food classes have
been produced by ICGFI, available through the International Atomic Energy
Agency, PO Box 100, A-1400 Vienna, Austria.
6.6 Records
of irradiation
Radiation processors
should maintain adequate records showing the food processed, identifying marks
if packaged or, if not, the shipping details, the bulk density of the food,
the dosimetry results, including the type of dosimeters used and details of
their calibration, the date of irradiation and the type of radiation source.
All documentation should be available to authorized personnel and accessible
for a period of time established by food control authorities.
6.7 Control
of hazards
Controls of microbiological
hazards are described in the Recommended International Code of Practice
- General Principles of Food Hygiene (RCP 01-1969, Rev 3-1997, Amd 1-1999).
The radiation processor should apply HACCP principles, as described in the
Codex Hazard Analysis Critical Control Point System and Guidelines for Its
Application (1999), as appropriate. In the overall HACCP context, irradiation
is a means of reducing hazards associated with infectious parasites and microbial
contamination of foods and may be used as a method of control.
7. POST-IRRADIATION
STORAGE AND HANDLING
Refer to the International
Code of Practice - General Principles of Food Hygiene (RCP 01-1969, Rev
3-1997, Amd 1-1999) for general storage and handling guidance.
8. LABELLING
The
Codex General Standard for Irradiated Foods (CODEX-STAN 106-1983, Rev.1
-2003) and the Codex General Standard for the Labelling of Pre-Packaged
Foods (CODEX-STAN-002, Rev. 1-1991) contain provisions for labelling of
irradiated foods, including the internationally recognized symbol (logo) and
the inclusion of information in shipping documents, and for the labelling
of prepackaged irradiated foods, respectively. All food labelling must meet
any additional requirements established by competen