Of course, the worldis not idealand thereare thingswe haveto do and accept
a compromise.To makerefillingof chemicals fromlarger containersor bulk
tanksinto smallercontainers as safe as possible thereare professional refilling
stationsavailable. Suchstationscan be designedto fill fromdrumsinto jerry
cans,to fill fromtransi-tanksintojerrycansor to fill frombulk tanks into
smallercontainers.
Thereare alsoso-called`userpacksolutions' to avoidmisuseof chemical
container for transporting and storing other goods.The user-packshavea closed
tab that cannotbe removedwithoutdestroyingthe container.Thistab fits onlyto
a valveon the filling station.Includingpersonnelprotection gearand hazard
information, ergonomicdesignsfor easyhandling and a safetyretainingarea to
retainspills,theserefilling stationsprovidemuch moresecuritybut still cannot
completely eliminatethe factorof humanerrorand failure.
39.3.4 Validations of clean surfaces to be freeof residues fromhygiene
products (withinlegal requirements)
A complete control of a confined surface (inside machinery, tanks and
pipework) is not possible, but thereare well-acceptedapproximation methods
thathaveproven their reliability, evenunder the stringent requirements of
pharmaceutical production. First, equipment should be designed to permit
proper drainage and there should always be sufficient time for draining.
Researchinto the behaviourof commoncleaningsolutionshas shown that after
proper draining, 20±40mL/mof the solutionare left on vertical equipment
walls.Thisequalsapproximately0.2±0.4mL of a product whenusedas a 1%
solution. Secondly, dependenton the foodproduct category(in Europe all
chemicals mustbe rinsedof dairyprocessingsurfaces but not necessarily from
meatproducts) or relevant national legislation, theseremaining solutionsmay
needto be rinsedoff withpotable water. Where it is acceptable to leave
disinfectantson surfaces, they must be non-toxic and non-taintingand may need
to be speciallyapproved.
Rinsingis relativelyeasy to control.In most casesthe conductivityor the pH of
the cleaningsolutionis differentfromthe pH and conductivityof the rinsewater.
In this case the rinseprocesscan be controlledby comparingthe conductivityand/
or the pH of the incomingrinsewaterto the usedrinsewaterleavingfromthe
rinsedequipment.Whenthereis no longera difference,the surfacehas been
sufficientlyrinsed. Thismethodcan be usedas a permanentinstallationor in a
moreor less frequentauditingprocessto validatethe cleaningprocess.
In the caseof particularingredientsone can collectrinsewatersamples
duringan extendedrinsecycle and analysethe samples for criticalingredients.
Thismorecomplex methodis usedduring validation of cleaning methodsin the
pharmaceutical industrybut mayalso serveas a tool in other industries to set
CIP parameters.However, even this method can only show and provea
sufficient rinsetime. There is still no informationaboutwhat mightstill be on
the surfacein the equipment.
Traceabilityof disinfectants and sanitisers 681