Frequently
Asked Questions
What
is food irradiation?
What is food irradiation used for?
How is food irradiated?
Who is in favour of food irradiation?
Who is concerned over food irradiation?
Is irradiated food radioactive?
Is irradiated food safe and wholesome?
Are irradiation plants safe?
Are there wider environmental implications
of food irradiation?
How is irradiated food identifiable?
Is it permitted for food labelled as 'organic'
to have been irradiated?
How will I know if restaurant food contains
irradiated ingredients?
Can unlabelled irradiated food be identified
by the consumer?
Can unlabelled irradiated food be identified
by regulators?
Q:
What is food irradiation? back to top
Food irradiation is a physical treatment of food involving very
large doses of ionising radiation to produce changes in food which
are considered desirable.
Q:
What is food irradiation used for? back
to top
The technology is promoted for preserving food and improving the
safety of food. Food irradiation can be applied for the following
purposes:
- To inhibit
the sprouting of some root vegetables eg potatoes and onions
- To delay
the ripening and ageing of some fruits and vegetables eg strawberries
- To kill
or sterilise some insects and parasites that infest food eg
grains, dried fruits, vegetables, nuts and meats
- To reduce
the levels of spoilage bacteria on some foods, such as fruit,
seafood, poultry and meat, enabling them to have a longer shelf-life
- To reduce
the levels of viable food-poisoning bacteria on seafoods, poultry,
meat and spices
Q:
How is food irradiated? back to top
Radiation for treating food can be sourced from machine generated
electrical energy or from radioactive materials. There are three
main methods to irradiate foods:
- High voltage
electricity: electric and magnetic fields are used to accelerate
electrons to high speeds and these can be used to bombard food.
- X-rays:
the accelerated electrons can be made to strike a metal target
and so be converted into x-rays which are then applied to the
food - much like the equipment used in hospitals or dental surgeries,
but larger.
- Radioactive
materials: food is exposed to radioactive materials, usually
cobalt-60 and occasionally caesium-137.
Q:
Who is in favour of food irradiation? back
to top
The food industry and national governments have shown little interest
in financing the research needed to convince governments that
the technology is safe. To overcome international inertia, the
International Atomic Energy Association (IAEA) established a Joint
Expert Committee on Food Irradiation (JECFI) with the UN Food
and Agriculture Organization (FAO) and the World Health Organization
(WHO). The IAEA has the UN mandate to control and develop peaceful
uses for atomic energy. It collaborates with the FAO on uses of
radiation in food and agriculture. Food irradiation was an important
area of development as it could use waste and by-products from
the atomic energy programme.
Since 1983,
the promotion of food irradiation has been led by the IAEA/FAO
International Consultatvie Group on Food Irradiation (ICGFI).
Late in 1986, this Consultative Group convened a task force meeting
or public relations and marketing experts to advise on how best
to promote acceptance of irradiation. The key elements involve
convincing the world's public that irradiation is vitally necessary
to deal with two critical food problems - food poisoning and world
hunger. The strategy calls for concerted efforts to promote acceptance
of irradiation by governments, industry, non-governmental organizations
and consumers.
Q:
Who is concerned over food irradiation? back
to top
Environment, consumer, women's, public health, trade union and
some food industry organisations have rejected the arguments put
forward for irradiation. In 1987 the World Congress of Consumers
Organisations unanimously called for a moratorium on any further
use or development of irradiation until a number of key issues
were resolved. In 1988 an international UN conference failed to
get agreement from participating countries on promoting acceptance
of irradiated food. Concerns of consumer and environmental organisations
were taken up by a number of government delegations. A proposal
to endorse the statement that there were 'no unresolved safety
issues' had to be withdrawn. Several major countries dissociated
themselves from the final resolution.
Q:
Is irradiated food radioactive? back to
top
Just as people are not made radioactive by chest x-rays, so irradiated
food is not radioactive. Provided the limitations on the energy
of the radioactive sources are adhered to, there should be no
significant risk of the food being made radioactive. Bombarding
food with high-energy radiation can cause some elements within
the food to become radioactive, however at the levels applied
in food irradiation the amount of radioactivity created should
be very small and die away rapidly. The UK Advisory Committee
suggests that, as a precaution, food should be stored for 24 hours
after irradiation before it is eaten. After this time has elapsed
any residual radiation would be undetectable against the 'background'
level of radioactivity in food.
Q:
Is irradiated food safe and wholesome? back
to top
The 1997 Joint FAO/IAEA/WHO Study Group on High Dose Irradiation
concluded that 'food irradiated to any dose appropriate to achieve
the intended technological objective is both safe to consume and
nutritionally adequate'. The Study Group also concluded that 'no
upper dose limit need be imposed' as 'irradiated foods are deemed
wholesome throughout the technologically useful dose range from
below 10kGy to envisioned doses above 10kGy'.
Unresolved
consumer issues: back to top
- Nutrient
loss
Food irradiation can result in loss of nutrients, for example
vitamin E levels can be reduced by 25% after irradiation and
vitamin C by 5-10%. This is compounded by the longer storage
times of irradiated foods. This is not in the interest of consumers,
least of all those in impoverished nations or sections of societies
already struggling to obtain adequate nutrition.
- Radiolytic
contamination
Irradiation of food produces chemical changes. The result is
a wide variety of radiolytic products. There is considerable
controversy over the safety of these products, over how they
might affect the people who eat them and future generations.
Some of these chemical changes are known to be harmful, both
mutagenic (altering genetic structures) and carcinogenic (causing
cancers). There is controversy over the amount of research being
undertaken to study these chemicals, and of the bias and quality
of past studies which are used as a basis for official opinions
on safety. One recent study found that hydrocarbons can form
from an irradiated egg's natural fats. Some hydrocarbons can
cause allergenic reactions while others are known carcinogens,
however there do not appear to have been any tests undertaken
of the hydrocarbons which formed in eggs.
Q:
Are irradiation plants safe? back to top
In recent decades incidents involving worker exposure to dangerous
levels of radiation have occurred in the USA, Norway and Italy.
In other incidents radioactive leaks have contaminated the areas
surrounding irradiation plants costing millions of dollars to
clean up. There have been cases of the theft and melting down
of cobalt-60 sources in Mexico and Brazil, illustrating how easily
widespread radioactive contamination can occur. The plants at
which these incidents took place were built and operated under
the internationally agreed system of regulation and control. The
prospect of increasing numbers of plants built across the world,
in some cases in regions where regulatory controls may be even
more difficult to enforce, poses very real risks.
Q:
Are there wider environmental implications of food irradiation?
back to top
Food irradiation supports the trend towards globalisation through
supporting centralised mass production and distribution of foods
worldwide. Prolonged shelf life allows foods to be transported
over greater distances contributing to increased fuel consumption
and air pollution, more road accidents, socio-economic decline
among small-scale local farmers and loss of wildlife habitats
to industrial farming and road construction.
Q:
How is irradiated food identifiable? back
to top
EC Directive 1999/2/EC requires all foods, or listed ingredients
of food, which have been irradiated, to be labelled with the words
'irradiated' or 'treated with ionising radiation'.
Q:
Is it permitted for food labelled as 'organic' to have been irradiated?
back to top
EU Regulation 2092/91 prohibits the irradiation of organic foods.
This applies throughout the member states of the European Union.
Q:
How will I know if restaurant food contains irradiated ingredients?
back to top
When food is not pre-packed and is sold for immediate consumption
(for example in restaurants), the indication of irradiation must
be marked or labelled on the menu, notice, ticket or label that
the customer can see when choosing the food. Use of the term 'may
contain' is no longer permitted.
Q:
Can unlabelled irradiated food be identified by the consumer?
back to top
The taste, smell, texture and appearance of irradiated foods are
usually no different to the same non-irradiated foods. Therefore
in most cases consumers cannot identify an irradiated food if
it has not been properly labelled as such.
Q:
Can unlabelled irradiated food be identified by the regulators?
back to top
Most irradiated foods or foods containing irradiated ingredients
can today be identified using specialised detection equipment
and techniques.
When minerals
(such as those found in shellfish or spices) are irradiated they
take on energy. This energy can be released using physical methods
such as heating the product and measuring the light released.
This is thermoluminescence testing, favoured by the UK's Food
Standards Agency (FSA).
Photo-stimulation
is another method of detection, developed by Dr David Sanderson
of the Scottish Universities Environmental Research Centre. Photo
stimulation releases stored energy by an optical technique, using
infrared radiation to detect blue and ultraviolet light emissions
and detect single photons. The advantage of this technique is
that it is cost-effective, sensitive to even minuscule quantities
of an irradiated product and very quick - an initial positive
or negative reading can be obtained in under a minute, indicating
whether further testing may be necessary.
It is common
practice to combine thermo-luminescence and photo-stimulation
testing to ensure reliability.
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