the pasteurisationof milkmustdelivera lethality equivalentto or more than
72 ÎC for 15 seconds.However,the emergence of newpathogens, increased
knowledgeof the survivalcapacity of pathogens, the development of novel
processingtechnologiesand the marketing of minimally processedfoodscreate
a greaterneedfor process validation.
The draftguidelinesset out a number of approachesthat maybe usedto
validate foodhygiene control measures.Onemaymake reference to previous
validation studies or scientific knowledge(for examplefor the heat treatmentfor
pasteurisation of milk),or conduct scientifically validexperimentaltrialson
laboratoryor pilot plant scale(forexample to document log reductionof
pathogensby a thermal process). Otherapproaches to validation are the
collection of biological, chemical and physicalcontaminantdata,bothduring
process establishment/commissioning and duringnormaloperatingconditions
and the use of statisticallydesignedsurveys(for example to validatethe effect of
hygienic equipmentdesignor personal hygiene). Mathematical modellingis also
mentionedas an approach(for example to estimatethe combinedperformance
of a combinationof alreadyvalidated control measures).
20.2.2 Riskassessment
The globalisation and liberalisation of worldfoodtrade,whileofferingmany
benefits and opportunities,also presents new risks. Because of the global nature
of foodproduction,manufacturingand marketing, infectious agents can be
disseminatedfromthe originalpointof processingto any placein the world.To
assistgovernmentalbodiesto achievean appropriatelevel of protection derived
fromthe free international tradeof food,the CodexAlimentarius Commission
has published guidelineswithgeneric principlesof riskassessment (CAC,
1999).According to the CAC,risk assessment consistsof the following steps:
(1) hazardidentification, (2) exposure assessment, (3) hazardcharacterisation
and (4) risk characterisation.In addition to thesestepsand priorto the beginning
of a particular risk assessment, the specific purposeof the risk assessmentshould
be clearlystatedand the output formand possibleoutputalternativesshould be
defined. Otherimportantprinciples are that the risk assessment should be based
uponscience, shouldbe transparentand its riskestimation should not be
influencedby preferential applicationof particular controlmeasures of the risk.
Hazard identificationconsists of the identification of biological, chemical
and physical agentscapable of causingan adversehealtheffect, whichmaybe
present in a particular groupof foods.Informationon hazards can be obtained
for example fromscientific literatureand studies of government agenciesor
internationalorganisations.
Exposure assessmentis the evaluation of the likelyintake of biological,
chemical and physicalagentsvia foodas well as exposures fromothersources if
relevant. For microbiological agents, exposure assessment determines the
likelihoodof consumption and the likelydoseof the pathogenor its toxinsto
whichthe consumers maybe exposed in a food.Exposure assessmentis one of
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