each irradiation; a condition that is readily preventable by good hygienic
practices and is most unlikely to occur.
The levels of radiation proposed for foods are not sufficient to induce
radioactivity in the product and there is no evidence that consumption of
irradiated foods is harmful. Food irradiation facilities do require strin-
gent safety standards to protect workers but that is already in place for
the irradiation of other materials such as the sterilization of medical
supplies and disposables.
By far the greatest obstacle to the more widespread use of food
irradiation is not technical but sociological in the form of extensive
consumer resistance and distrust. Much of this is based on inadequate
information and false propaganda and parallels very closely earlier
arguments over the merits of milk pasteurization. Among the same
objections raised then were that pasteurization would be used to mask
poor quality milk and would promote poor practices in food preparation.
While it has to be agreed that those who take the most cynical view of
human nature are often proved correct, this did not prove to be the case
with milk pasteurization where the production standards and microbio-
logical quality of raw milk are now higher than they have ever been.
Depending on the lethality required, food irradiation can be applied at
two different levels. At high levels it can be used to produce a safe shelf
stable product in a treatment known asradappertization. Though this has
been investigated in the context of military rations, it is unlikely to be a
commercial reality in the forseeable future.C.botulinumspores are the
most radiation resistant known, so very high doses are required to
achieve the minimum standard of a 12D reduction (E45 kGy) for low-
acid foods. In the event of a process failure, the growth of more resistant,
non-pathogenic clostridia would not act as a warning as it can in thermal
processing. High radiation doses are also more likely to produce unac-
ceptable sensory changes and the product has to be irradiated in the
frozen state to minimize migration of the radiolytic species that cause
such changes. These considerations would not apply when the food was
inhibitory to the growth ofC. botulinumas a result of low pH or the
presence of agents such as curing salts.
Two terms are used to distinguish different types of radiation pas-
teurization.Radicidationis used to describe processes where the objective
is the elimination of a pathogen, as, for example, in the removal of
Salmonellafrom meat and poultry.Radurization applies to processes
aiming to prolong shelf-life. This distinction may be thought a little over
elaborate since, as with thermal pasteurization, irradiation treatments
are relatively non-discriminating and will invariably improve both safety
and shelf-life.
Several potential applications have been identified (Table 4.9) and
food irradiation for specific applications is now permitted in more than
Chapter 4 89