Facility Monitoring and the routine periodic documentation of this information are vital to maintaining the cleanroom facility at optimal operational efficiency.
Regardless of the manufacturer you select for your facility monitoring instrumentation, a decision has to be made early on as to how stringent the sensor tolerance must be for your specific application. IE: Can you accept a 3% tolerance of your Relative Humidity reading or do you need a 0.5% tolerance. This is where you do not want to buy price and want to know about on-site calibration or the turn around time for off-site calibration.
The first line of defense is the monitoring of the cleanroom’s pressurization, from the main cleanroom outward to lesser clean areas. Whether you have a remote monitoring system or gages on the wall, it is imperative that the Cleanroom Manager be aware of what the pressure readings are, on a daily basis.
If you are using gages that are measuring the pressure differential, have these gages mounted in a panel box on the wall just outside of the gown room where no one can avoid seeing them upon entering the room. This panel box will provide access for the calibration of these gages on an annual basis, as there is no such thing as a “For Reference Only” sticker in lieu of a calibration sticker when it comes to the first line of defense of monitoring.
It is also beneficial to monitor the ongoing pressure differential of the HEPA filters versus the initial pressure drop when the filter was new. Usually the monitoring of one HEPA filter is sufficient for this application in order to give a snap shot of all of the HEPA filters so that you will be aware of when to change them in accordance with current industry guidelines.
Regarding airborne particle counting: where will you place the sensors in a remote monitoring installation application that will provide you with real readings?
OR if a designated trained Technician will be doing manual readings with a particle counter make sure that the particle counter, hose, and probe are “zero counted” prior to taking any readings. Also note the elevation of the particle counter probe on the report sheet as well as the operational mode of the room when the counts were taken.
Don’t forget the Viable (Microbial) Monitoring Program, if applicable.
When doing any monitoring, it is the monitoring Technician’s responsibility to be observant of any items that may have a negative impact on the cleanroom’s environment, such as unsealed penetrations in the walls or ceiling, broken light lenses, unseated or broken ceiling tiles, etc. and report them to the Cleanroom Manager.
In summation, history has proven that a continued, routine, documented Monitoring Program, in conjunction with good protocol, personnel disciplines, and housekeeping is a vital part of your cleanrooms Standard Operating Procedures.