Keeping Product Clean In and Out of the Cleanroom
-- (Part 1) The Interface
By Barbara Kanegsberg, EdKanegsberg,KevinaO’Donoghue
Are you aware that incorrect materials transfer could pose oneofthe biggest potential sources of contamination within acleanroom?How many of you can say that while performing thetransfer ofmaterials into the cleanroom environment you are fullyaware ofyour actions, practices, and methods?
KEEP THE PRODUCT CLEAN
Paperwork, raw materials for manufacturing the product, tools,andequipment must be successfully transferred to the cleanroom.Thegoal of a materials transfer program is to keep contaminationfromthe outside world from entering the cleanroom. Benefitsofinvesting effort in a materials transfer program includehigherquality product, lower costs, and an enhancedcompetitiveposition.
Some materials are double bagged, some single bagged, and maybestored for long periods of time in cardboard boxes inwarehouseenvironments. Other materials such as tools may not bebagged atall and are likely to have come from anuncontrolledenvironment.
Contamination control protocols for material transfer arevital.Materials brought into the cleanroom that have not beencleanedeffectively during the transfer process are an immensesource ofparticulate and thin film contamination. Inadequatelycleanedmaterials can be a huge source of spore forming bacteria,extremelyresistant bugs that are very difficult to eradicate fromacleanroom environment. Manufacturers of all critical productshouldbe concerned about the impact of biological contamination,not justthose producing medical devices and pharmaceuticals. Manypeopleare not aware that biological contamination willdramaticallyaffect particulate counts which are required in everycleanroomindustry. At the same time, sterility is not enough; “deaddirt”can wreck havoc with critical devices. Water solublelubricants andnear-neutral pH processes can provide water, warmth,and nutrients,a favourable environment for biologicalcontamination.
ROOM DESIGN
Materials transfer maybethrough a hatch leading directly from an unmonitoredmanufacturingarea to a cleanroom or a transfer hatch between twocleanrooms. Isthis an optimal arrangement for your process? With ahatch,employees are tempted to stand on either side, engaging inlivelyconversation, even enjoying their morning coffee. Suchbehaviourincreases the likelihood of contamination. For newconstruction,consider a material transfer room.
Material transferroomsshould function like gowning rooms with a ‘clean’ side anda‘dirty’ side. Very often a line of tape separates these areas.Inpractice, a “line in the sand,” does not keep personnelfromcrossing over to the ‘clean’ side inadequately gowned or instreetclothes. Too often we see issues with high levels ofcontaminationon the ‘clean’ side of the material transfer roomwhere the rootcause is the ‘dirty’ side.
Rather than a stripoftape, consider an “étagère,” a physical barrier such as rackingorcabinets that allows expedited transfer of materialswhilediscouraging personnel movement to the clean side. If rackingorcabinets are on wheels, it is simple to move them to allowaccessof large equipment or bulky materials. Of course, becausesuchbarriers are not physically distinct rooms, the dirty side ofthetransfer room should also be fairly clean.
CONVENIENCE
Cleaning materialswithinthe transfer area must be convenient. A wipe down stationshouldalways be visible in the material transfer room with alow-residuecleaning agent such as isopropyl alcohol (IPA) andlow-lint wipesreadily accessible. If there is a hatch rather thana room, considerwipe down stations immediately before andimmediately aftertransfer. If no wipe down station is present,there is thetemptation for personnel to pass material in withoutcleaningit.
TRANSFERVERSUSGOWNING
Thechanging/gowningareas should not be used for wiping down andtransferring materialsto avoid potential contamination of personneland cleanroomclothing. Good practice within a cleanroom shouldgenerally allowclean materials to come in one way and usedmaterials to exit byanother area.
STAY TUNED
In Part 2, wewilldiscuss techniques for cleaning during transfer, managingbulkymaterials, and automation.
Dr. Kevina O’Donoghue,isa Microbiologist at Specialized Sterile Environments,Galway,Ireland. She can be reached at kevina@cleanrooms.ie.
Barbara Kanegsberg andEdKanegsberg, “the Cleaning Lady and the Rocket Scientist,”areindependent consultants in critical and precision cleaning,surfacepreparation, and contamination control. They are the editorsof TheHandbook for Critical Cleaning, CRC Press. Contact them atBFKSolutions LLC., 310-459-3614;info@bfksolutions.com;www.bfksolutions.com.