8.4.6 Liquidand solidwastes
On no account shouldlow-risk liquidor solidwastes be removedfromthe
factory via highrisk and attention is required to the procedures for removing
high-riskwastes. The drainagesystem should flowin the reversedirectionof
production (i.e. fromhighto low risk)and wheneverpossible, backflow from
low-risk to high-riskareasshould be impossible.Thisis best achievedby having
separate low-and high-riskdrainsrunning to a mastercollectiondrainwithan
air-breakbetween eachcollectorand masterdrain.The high-risk drains should
enterthe collectiondrainat a higherpointthanthe low-risk drains,so that if
flooding occurs, low-risk areasmay floodfirst.The drainagesystemshouldalso
be designedsuchthat drainaccess pointsthat can be usedfor draincleaningor
unblocking(rodding)are outside high-risk areas.Solidsmust be separatedfrom
liquids as soonas possible, by screening,to avoidleachingand subsequenthigh
effluent concentrations. Trapsshouldbe easilyaccessible, frequently emptied
and preferablyoutside the processing area.
Solidwastes in bagsshould leavehighrisk in sucha way that theyminimise
any potential cross-contamination with processed product and should,
preferably, be routedin the reversedirection to the product. For smallquantities
of baggedwaste, existinghatchesshouldbe used,e.g. the wrappedproduct exit
hatchesor the packagingmaterials entrancehatch,as additionalhatchesincrease
the risk of external contaminationand put extrademandson the air-handling
system. For wastecollected in bins,it maybe necessaryto decant the waste
through purpose-built,easily cleanable(from highrisk),waste chutesthat
deposit directly intowaste skips. Waste bins should be colour coded to
differentiate themfromotherfoodcontainersand shouldbe usedonlyfor waste.
8.4.7 Personnel
The high-risk changing room provides the only entry and exit point for
personnelworking in or visitinghighrisk and is designedand builtto bothhouse
the necessary activities for personnel hygiene practices and minimise
contaminationfrom lowrisk.In practice, thereare somevariationsin the
layoutof facilitiesof high-riskchanging rooms. Thisis influencedby, for
example, spaceavailability,productthroughputand type of products, whichwill
affectthe number of personnelto be accommodatedand whether the changing
roomis a barrier between low-and high-risk operativesor between operatives
arrivingfromoutsidethe factory and highrisk.Generallyhigherconstruction
standards are required for low/high-risk barriersthanoutside/high-risk barriers
because the levelof potentialcontamination in low risk (fromraw materials),
bothon the operatives' handsand in the environment, is likely to be higher.
A genericlayout for a changingroomshould accommodatethe following
requirements:
∑ An area at the entrance to storeoutsideor low-risk clothing.Lockers should
havesloping tops.
Improvingzoningwithinfoodprocessingplants 161