Establishing a fluid barrier between the non-sterile environment and the sterile field is probably the single most-controllable aspect of maintaining good sterile technique. And yet, most veterinary practices incorporate less than adequate barriers by using worn out muslin pack wraps – and storing them on the shelf for months or years – and less than optimal products and techniques in surgery to eliminate the risk of fluid penetration.

The liquid barrier – critical in sterile processing and in the OR – must be maintained in order to prevent microorganisms such as bacteria, fungi and viruses from passing from the environment to sterilized instruments within a pack or through surgical drapes from the patient to the surgical site.

Barrier classifications are established by the Association for the Advancement of Medical Instrumentation (AAMI). The four-level classification system establishes minimum requirements for protective apparel and based on their liquid barrier performance (e.g., efficacy against liquid or liquidborne microorganism penetration). AAMI Standards

In short, if fluid can pass through your drapes, including your instrument tray wrappers, you’re barrier is not up to standard and is a potential source of infection. Every single AHS product, including our innovative, engineered Everlast Sterilization Tray wraps, meets AAMI Level 3 or higher. Do yourself a favor – if you’re going to bother to autoclave instruments, be certain you’re not exposing them to contaminants by using worn out cloth wraps.

What are the AAMI Standards?

AAMI Liquid Barrier Classifications

Level 1 – Gowns and Drapes (the minimum level)
Describes surgical gowns, other protective apparel, surgical drapes, and drape accessories that demonstrate the ability to resist liquid penetration in a laboratory test, AATCC 42 (Water resistance: Impact penetration test).

Level 2 – Gowns and Drapes
Describes surgical gowns, other protective apparel, surgical drapes, and drape accessories that demonstrate the ability to resist liquid penetration in two laboratory tests, AATCC 42 (Water resistance: Impact penetration test) and AATCC 127 (Water resistance: Hydrostatic pressure test).

Level 3 – Gowns and Drapes (minimum for AHS products)
Describes surgical gowns, other protective apparel, surgical drapes, and drape accessories (such as tray wrappers) that demonstrate the ability to resist liquid penetration in two laboratory tests, AATCC 42 (Water resistance: Impact penetration test) and AATCC 127 (Water resistance: Hydrostatic pressure test). For Level 3, the test criterion for AATCC 127 performance is set at a higher value than for Level 2.

Level 4 – Gowns and Drapes (the highest level)
Describes surgical gowns and protective apparel that demonstrate the ability to resist liquid and viral penetration in a laboratory test, ASTM F1671 (Standard test method for resistance of materials used in protective clothing to penetration by blood-borne pathogens using Phi-X174 bacteriophage penetration as a test system). Barriers in surgical drapes and drape accessories also must demonstrate the ability to withstand penetration over a period of time and against the application of pressure, which would help facilitate the fluid transmission through the barrier.