To provideprotection fromgeneral contamination(physical,chemicaland
biological hazards)duringmanufacture,foodhas historicallybeenprotected by
a barrier system,madeup of up to threebarriers (Holah and Thorpe2000).With
the adventof enhancedhygiene control in highhygiene areas, however, this has
nowbeenextendedto fourbarriers as shown in Fig. 8.1 (Holah 2003).These
encompass the site (1), the factory building (2), a highrisk or highhygienezone
(3) and a product enclosurezone(4). In this system the degreeof controlof the
production environment increases suchthat,finally,fullyprocessed products are
manipulatedin controlled environmentsin which contaminantsare actively
excluded.
Withrespectto segregation requirements,foodsand drinkscan be broadly
dividedinto low-and high-riskproducts dependent on theirstabilityor whether
theywill be furtherprocessed by the foodmanufactureror the finalconsumer.
Low-risk products, typically either raw materials or ambient shelf-stable
products, includeeggs,raw meatand fish,fruitand vegetables,driedgoods,
canned foods, bakeryand baked products, confectionery, snacks, breakfast
cereals, oils and fats, food additives/ingredients and beverages. High-risk
products, typically short shelf-life ready-to-eat foods, include cooked and
smokedmeat and fish, preparedvegetables, preparedfruit,milk, cream, cheese,
yoghurt, ice cream, sandwiches and ready meals and generally require
refrigeration at chilltemperatures.
The number of factorybarriers requiredwill be dependent on the natureof
the foodproduct,the natureof the hazardand the profile of the finalconsumer,
and will be established from the Hazard Analysis Critical Control Point
Fig. 8.1 Schematicdiagramof the fourlevelsof hygienebarrierpotentiallyfoundin
foodfactories.Improvingzoningwithinfoodprocessingplants 149