Luers and small bore connector systems; the new ISO 80369 and how it could affect your testing

Replacing the ISO 594

Previously, the ISO 80369 has been used in tandem with the ISO 594. This was seen as problematic, because in a medical environment (such as a hospital) a lack of coherency between these two standards could lead to serious complications.

For instance, a mis-connection between the Luer connection of an infusion set (ISO 594) and the small bore connector of a vein lock (ISO 80369) could result in harm to the user.

Therefore, a common connector system which describes a wider range of small bore connectors is desired. These connectors should be safe to use and easy to operate.

The new ISO 80369 has replaced the ISO 594 to form more coherent standardized connector systems and procedures.

Understanding the new ISO 80369

The new ISO 80369 can be divided into three sections.

General Requirements [ISO 80369-1]

Outlines the specifications applied to small bore connectors along with healthcare fields in which they are intended to be used.

Test Methods [ISO 80369-20]

Outlines test methods applied to different small bore connectors depending on their intended usage. Details of these tests can be found below.

Requirements specific to purpose [ISO 80369-2,-3,-4,-5,-6,-7]

Different levels of assessment including tolerances and forces applied maybe more strict depending on the intended usage of the connector under examination. Therefore, it is important to know the intended real world application of a connector when testing is performed. 

Reference connectors

Arguably the most dramatic change in the new ISO 80369 involves the usage of reference connectors.

ISO 80396 has introduced highly detailed descriptions for both male and female reference connectors along with special geometries depending on the intended application of the small bore connectors being tested.

Compared to ISO 594, the new ISO 80369 requires a wider variety of reference connectors depending on the testing being performed.

While some connectors need only work mechanically, other must have connections which make applying positive, negative, or sub-atmospheric pressure possible. For example, a test measuring leakage may require a reference connector with both: a male conical fitting and a means of attaching tubing through which either air or water may flow.

The details of these reference connectors are outlined in the Annexes of ISO 80369-2,-3,-4,-5,-6,-7.

The application of test methods

Tests outlined in ISO 80369-20 can be divided into two categories. Mechanical tests and Leakage tests.

Mechanical tests are used to assess the resistive properties of small bore connectors when forces in the form of axial loads, unscrewing, and overriding are applied.

Leakage tests are used to assess whether or not air/water is allowed to pass between the connection of a reference conical fitting and the small bore connector under tested when subjected to either positive, negative, or sub-atmospheric pressure.

Stress cracking, a test where samples are connected, conditioned, then examined for cracks and leakage is also applicable to ISO 80369-20.

It is important that testing is performed by experienced technicians using accurate equipment in a manner which is consistent and repeatable. MET offers world class Luer/Small Bore Connector testing to the standards referred to in this article.

Article authored by Mark Saxby, Senior Lab. Technician, Physical and Biological Team.