Simply put, every square inch of a cleanroom should be absolutely pristine. Ceiling panels, lighting units, HEPA filtration units, sprinkler heads, walls, glass surfaces, process equipment, piping systems, floors, and manufacturing equipment should all be decontaminated regularly. Even the ambient air must be monitored and maintained at proper levels. HEPA-filtered ventilation systems assisted by preventative measures help manufacturers limit airborne contamination. However, in order to assure environmental purity, regular housecleaning procedures are necessary.
Cleaning with both a HEPA-filtered vacuum and traditional wipe-down methods are standard housekeeping procedures in most cleanrooms. Yet in critical cleaning situations, vacuuming is often the more efficient method because particles are retained inside the machine with little chance of being exhausted into the atmosphere (provided your vacuum has a HEPA-filtered exhaust stream). Vacuuming also eliminates the fiber particles that swabs and wipers may leave behind. In fact, measurements taken in one cleanroom setting found that a dusting system using disposable cloths polluted the space twice as much as a system using a HEPA-filtered vacuum cleaner.
So, what should your cleanroom vacuum include? First and foremost, any vacuum cleaner used in a biotech parenteral cleanroom must be HEPA-filtered to ensure that 99.97% of all particles down to and including 0.3 microns are collected and retained. In addition, it is absolutely critical that the HEPA filter be installed after the motor to filter the exhaust stream. The motor’s commutator and carbon brushes generate dust, and if the exhaust stream is not filtered that dust will be released into the environment.
A word of caution: not all HEPA-filtration systems are created equal. Make sure the vacuum you select contains a multi-stage, graduated filtration system for peak operating efficiency. A graduated filtration system uses a series of progressively finer filters to trap and retain particles as they move through the vacuum. The largest particles are captured first by coarser filters; smaller particles are then caught and retained by the finer HEPA filters. This multi-stage system protects the HEPA filters from blockage and excessive wear-and-tear, maintaining peak performance. (When equipped with an ULPA filter, the system should retain up to 99.999% of all ultra-fine particles, down to and including 0.12 microns in size).
Additionally, the filtration system in your vacuum should use oversized filters, which slow airflow across the larger surface area and optimize the air-to-cloth ratio. This allows the vacuum to easily collect large volumes of debris over extended periods of time with minimal maintenance.
Besides having an exceptional filtration system, any vacuum used in a cleanroom should be constructed of non-particle-generating materials. For example, non-porous, stainless steel vacuums – equipped with smooth hoses and attachments – enable personnel to quickly wipe down and decontaminate equipment for faster, simpler sanitization and validation. And, it must be specially packaged to prevent contaminants from entering the cleanroom environment when delivered.
Vacuum Tip:
Don’t forget to take spill response into account when purchasing a vacuum. At least one of your vacuums should be capable of wet and dry collection.
*High Efficiency Particulate Air
**Ultra Low Penetration Air
