ISO 14644-7 Transfer Devices - Foster Wheeler Italiana

ISO 14644-7 Annex DD.6 C1 transfer device• The C1 transfer device (see Figure D.5) has doors and HEPA filters which, when used in a positivepressureseparative device and operated in the correct sequence, do not allow unfiltered air from thebackground environment to reach the separative-device environment but which may allow unfilteredair from the separative-device environment to reach the background environment. Such transferdevices are not suitable for negative-pressure separative devices because unfiltered air from thebackground environment would be allowed to reach the separative-device environment. C1 transferdevices are not recommended where operator and third-party protection is required in positivepressureseparative devices.• EXAMPLE Single-filtered transfer chambers.1 separative-device environment2 airflow3 background environment4 HEPA filter5 positive pressure6 ingress7 egress8 sealed door9 work surface of controlled workspaceFigure D.5 — C1 transfer device32