SacO2 Microsac Information

SacO2's Microsac Filter stands out with its revolutionary depth-filtration system. Unlike traditional spawn and substrate bags that use surface filtration, Microsac Filters leverage a unique system of randomly arranged fibres, trapping microorganisms effectively. This system, akin to the HEPA-filter technology, ensures fluent gas exchange without creating dry zones below the filters, while providing robust protection against pests and diseases​​.

Operating Principle of the Microsac Filter

This revolutionary depth-filtration system allows for air flow, but blocks contamination, providing the best available protection against pests.

Technical Advancements

Microsac bags are designed with exceptional qualities:

  • Autoclavable: Enduring temperatures up to 124°C (255°F), suitable for sterilization processes.
  • Enhanced Gas Exchange: Filter strips run the entire length of the bag, ensuring optimal gas distribution.
  • Durability: Rigorously tested for strength post-heat treatment and handling.
  • Visibility: The bag's material and filter design allow for excellent visual quality control.
  • Flexibility and No Dry-out Zones: Customizable bag lengths and filter distribution tailored to specific gas exchange requirements, while minimizing substrate dehydration​​.


PPD bags are crafted from durable polypropylene, suitable for autoclaving. PE bags, made of polyethylene, can't be autoclaved but are sterilised using gamma irradiation.

We offer 'Filters Up' Microsacs for spawn production, and another variant with filters evenly distributed, suitable for larger grain carriers.

The S-filter, allowing more gas exchange, is ideal for Substrate, whereas the R-filter, with less gas exchange, is suited for Spawn.

Store them in a clean, dry place, ideally above 15°C. Avoid freezing temperatures to prevent damage to PP bags.

A heat sealing device is recommended for both types of Microsacs.

Our PP bag codes include information on film type, filter type and location, and size. PE bags’ codes similarly detail film type, filter material, orientation, and dimensions.

Use a wet steam autoclave at 121°C and 1 bar overpressure, ensuring the filters don't touch the substrate.

Our PE bags undergo gamma irradiation for sterility and are packaged in multiple layers for convenience and safety.

Our filters are made from non-woven materials without a specific micron rating. Our bags are not Air Plasma treated, enhancing strength and seal durability.