Follow Policies and Procedures for Rigid Container Filters

Man-made filter for rigid container system

By Nancy Chobin, RN, AAS, ACSP, CSPM

Q: Recently, we ran out of the single-use filters for our rigid containers. I learned the staff was making their own filters out of packaging material (see photo above). What advice can you provide when something like this happens? 

A: The Association for the Advancement of Medical Instrumentation (AAMI)'s ANSI/AAMI ST77:2013, “Containment devices for reusable medical device sterilization” and ANSI/ AAMI ST79:2013, “Comprehensive guide to steam sterilization and sterility assurance in healthcare facilities” should be used as references for rigid container systems.

A rigid sterilization container is defines by AAMI as a “sterilization containment device designed to hold medical devices for sterilization, storage, transportation, and aseptic presentation of contents. They are valuable tools in sterility maintenance and to prevent damage to surgical instruments and devices.”

Filter(s) are secured to the container’s lid and/or base. The filter permits the passage of air and sterilants however it also provides a microbial barrier. There are many choices in filters today; reusable, disposable (single-use) or permanently affixed to the container.

According to ANSI/AAMI ST: 77, “The filters of reusable rigid sterilization containers shall completely cover the sterilization port(s). The means by which the filter is held in place shall provide a tight uniform seal. Filters shall be protected to prevent tears and potential damage. The filters and filter retention mechanisms shall provide a microbial barrier. Compatibility of the filter with the specified sterilization modality shall be demonstrated.”

Always check the manufacturer’s instructions for use for the type of filter material recommended by your container manufacturer.  If you are using rigid containers in low temperature sterilization (e.g., gas plasma) you will need a polypropylene filter material as paper filters are not compatible with these low temperature sterilization processes.

The golden rule for single use filters is that the filter material used must be from the rigid container manufacturer. Do not attempt to substitute filters from another vendor unless that vendor has validated their filter has been tested for compatibility with your container. Never reuse filter material.
You should never attempt to make your own filter. Rigid container filter material has been specifically designed by the respective container manufacturer for their container.  Only rigid container manufacturers can perform this process.  By making your own filter you are putting the patient at risk since you have no documentation as to the effectiveness of the filter’s ability to perform as intended nor do you have any scientific evidence of the microbial barrier of the filter.

If the filter material is not available, there are several things you can do:
1. Contact your container manufacturer; usually they have a back-up supply they can provide to you.
2. Try to borrow from another facility that is using your exact rigid container system.
3. When all else fails, remove the inner basket from the container and wrap in disposable wrap.
Your department should have a policy and procedure for care, handling, testing and use of rigid containers to direct this practice.

Nancy Chobin, RN, AAS, ACSP, CSPM, is president and CEO of Sterile Processing University, LLC.