Liquid barrier textiles for protective apparel and drapes used by health care facilities are tested and classified in 4 different levels, as per AAMI / ANSI PB 70.

This specification is designed for surgical gowns, surgical drapes, and other protective apparel with liquid barrier claims.

Here is a short description of the required test properties.

Level 1 requires the AATCC 42 standard test method. This test measures textile resistance to water impact using a spray tester. The maximum allowed quantity of water to pass through the material is established at 4.5 g.

A test procedure is displayed here on our Youtube channel:

Level 2 Requires the same AATCC 42 test with a maximum acceptable limit of 1.0 g ; with the addition of the AATCC 127 test for water penetration (water column test). This later test consists in determining the pressure required for the water to get through the fabric (the higher the better). The acceptance level is minimum 20cm of water pressure.

A test procedure is displayed here on our Youtube channel:

Level 3 : for this level, AATCC 42 limit is 1.0g maximum (same as level 2) and AATCC 127 limit is increased to a minimum of 50cm of water pressure (the higher the better).

Level 4 reflects an enhanced protection grade by estimating resistance to synthetic blood applied under pressure and over time, as per ASTM F1670 (see our video of ASTM F1670 below, and a viral penetration test as per ASTM F1671 (not performed at the CTT Group). This performance level is mainly designed for laminated or coated fabrics.

In addition to these requirements, a statistical analysis with an Acceptance Quality Level of 4% and a Rejectable Quality Level of 20%, for each of these tests is required.

Note that some of these tests may include sealed seams samples, based on the garment type and level of protection. If these properties are mandatory after wash, these tests shall be performed after the number of launderings recommended by the manufacturer.

At this moment, the CTT Group is able to help you evaluate your textiles for levels 1 to 3, and can provide testing for some aspects  of level 4 requirements.

If you have further questions about this tests, contact-us: