∑ the flowof air and drainageshouldbe awayfromclean'areastowards dirty'ones;
∑ the flowof discardedouterpackagingmaterialsshould not cross,and should
run counter to, the flowof eitherunwrapped ingredientsor finishedproducts.
The key differentialbetweensegregationbarriers at this and the next level(high-
care/high-risk areas), is that foodoperativesare freely able to movebetween the
segregated areaswithoutany personnelhygienebarriers(though hand-washing
maybe required in orderto movebetween some areas).
Whilea rangeof ingredients is brought together for processing,they may need
to be storedseparately. Storagemaybe temperatureorientated (ambient,chilled
or frozen)or ingredientrelated,and separate storesmay be required for fruit and
vegetable, meat, fish dairyand dry ingredients.Otherfoodingredients, suchas
allergens, and non-ingredients, such as packaging, should also be stored
separately. Segregation mayalso extendinto the first stagesof foodprocessing,
wherefor example the production of dry intermediate ingredients,e.g. pastryfor
pies,is separated fromthe production of the pie fillings.The degree of segrega-
tion for storageand processingof ingredientsand intermediatesis predominantly
controlled by the exclusionof water,particularly in howtheyare cleaned,i.e.:
∑ Dry cleaning.Thisapplies to areas where no cleaningliquidsare used,only
vacuumcleaners, brooms,brushes, etc. Althoughtheseareasare normally
cleaneddry, occasionally theymaybe fullyor partiallywet cleaned,when
limitedamountsof waterare used.
∑ Wet cleaning.This applies to areaswhere the entireroomor zoneis always
cleanedwet.The contents (equipment, cabletrays,ceilings,walls),are wet
washedwithoutrestrictionson the amountof cleaningliquidused.
In addition to segregatingdry areas froma requirement to excludewater, other
areasmay needto be segregateddue to excessive use of water, whichcan lead to
the formation of condensationand the generationof aerosols. Such areasinclude
tray-washer and othercleaningareas.
Thecontrol of microorganisms within food processing areas can only
adequately be controlled by inclusion of third level (high-care/high-risk)
barriers. Otherhazards,however, haveto be managedat the second barrierlevel,
particularly allergens. This is to preventthe possibility of accidentalcon-
tamination of products not containingallergens(andparticularlythoseproducts
not labelledas `maycontainallergens')withallergensintendedfor use in other
products. Ideally,manufacturerswho manufacture allergenic and non-allergenic
products shoulddo so on separatesitessuchthat thereis no chanceof cross-
contaminationfromdifferentingredients.Thisissue has beendebatedby food
manufacturersin bothEuropeand the USAwiththe conclusionthat it is unlikely
to be economically viableto process on separate sites.Segregationof allergenic
components will haveto be undertaken,therefore,within the samesite.
As a preferredalternativeto separate factories, it maybe possible to segre-
gatethe whole process, from goodsin through raw material storage and
Improvingzoningwithinfoodprocessingplants 153