Sterile gas filtration

For gas filtration in a vent application, sterilizing grade filters can be used in both directions. We offer the following products:

• Emflon™ II V002PV
• Emflon™ PFR
• Emflon™ HTPFR
• Acro™ 50 (6074270)
• Acrodisc™ KM292HPL

These filter devices feature a symmetrical filter media construction, where two layers of membrane of the same pore rating are used in the manufacturing of the final filter cartridge or capsule.

When a filter of a symmetrical media construction is used for venting purposes, in either forward or reverse flow direction, the gas flow and any contaminants will travel through a torturous path of the same characteristic and length as in the forward direction. This will lead to the same retention efficiency in either flow direction.

Based on the symmetric media construction the filter will thus act as a sterile barrier when venting in either flow direction. Therefore, Emflon™ II V002PV, Emflon™ PFR, Emflon™ HTPFR, Acro™ 50 (6074270), and Acrodisc™ KM292HP filters can be used for bi-directional flow applications under this venting mode of filtration.

Emflon™ HTPFR filter cartridges are specifically designed for the sterile filtration of gas in critical applications in the biopharmaceutical and biotechnology industries, where the following environmental conditions maybe present:

• High-temperature applications where the gas to be filtered exceeds 60°C in continuous operation, including autoclave, fermentation inlet air, aseptic packaging/blow-fill-seal, and hot water for injection (WFI) tank vents
• Ozonated-water tank vent applications
• Oxygen-enriched applications in fermenter or bioreactor applications where improved aeration enables higher product yield

Emflon™ HTPFR incorporate a double-layer (0.2 μm) of inherently hydrophobic polytetrafluoroethylene (PTFE) membrane. The polypropylene hardware is specially formulated with protective anti-oxidants and the filter’s support and drainage layers are made of polyphenylsulphide (PPS) polymer to minimize combustibility. Oxidation-resistant membrane and cartridge components allow extended use in air/vent service up to 100°C and for shorter periods up to 120°C.

For more information, please see:

• Safety considerations for gas filtration in high-temperature and oxygen enrichment applications
• Sterile vent filtration on ozonated water tanks
• Sterilizing filtration of enriched and pure gaseous oxygen employed in cell culture applications