Particle Monitoring in Sterilizing Tunnels
Portable aerosol particle counters are designed to sample ambient air at 1 cubic foot per minute (1 cfm) and no greater than 35 oC. There are however applications which are based on ambient temperatures much greater than this, such as pharmaceutical sterilizing tunnels. Sterilizing tunnels are used to ensure sterility off glassware (vials, syringes, bottles) prior to their entry onto an aseptic filling line, where internal temperatures can reach up to 200ºC.
The question of monitoring particle levels within these class 100 (ISO Class 5) areas, to prove that the area remains within specification raises two separate issues: do we need to monitor in these areas? If so, how do we monitor in these areas?