Luer ISO 80369-7 Compliance: Preventing Catastrophe

CT scanning luer dimensions for IV & hypodermic applications.

Victoria Russman
Victoria Russman

Luer ISO 80369-7 Compliance:

(This article was updated June 16, 2021 to reflect the release of ISO 80369-7: 2021)

The luer is a small-bore connector or fitting for leak-free connections used in intravascular applications or hypodermic applications of medical devices. For example syringes, IV lines, and feeding tubes. The luer was invented by Karl Schneider and gets its name from a 19th-century German medical instrument maker Hermann Wülfing Luer. Luers were standard across the board for the transference of liquid or gas to patients. This means two incompatible devices could be connected. Problem? Absolutely. Solution? Simple, but complicated. Luer ISO 80369-7 compliance would prove to be the answer and Nel Pretech is helping customers with these new dimensional inspection requirements.

In fact, ISO 80369-7 is years in the making. It takes time to form leadership and develop a coordinated effort to make such a change on a vast scale. Manufacturers couldn’t implement widespread change and conformance on their own. They needed a governing body to guide them. Other solutions like color coded luers did not provide adequate change that was needed. The newly formed standardization is designed to minimize risk of medical misconnections and will affect small bore tubing connectors across the globe. As of December 31, 2019 the FDA no longer accepts new medical device designs for intravascular or hypodermic applications incorporating the luer that do not comply with the ISO 80369-7 standard. In May of 2021 the ISO published a new release of ISO 80369-7 and compliance for existing products has been pushed back from October 2021 to a later date.

The luers we are referencing connect to tubes or needles that deliver medicine needed to reach the bloodstream, tubes that need to access the stomach, tubes to deliver gas for breathing, and tubes to access the spine to name just a few. Prior to the ISO standard, the luer or connector was universal; one luer that works with all medical tubing. This was becoming dangerous as more and more devices were being implemented in hospitals and accidental connections of liquid or gas were sometimes being delivered to the wrong area in the patient with catastrophic results. It was becoming clear this was a matter of life or death.

The solution or ISO 80369-7 is to prevent cross connecting by manufacturing enteral connectors or feeding tube connectors that are not compatible with non-enteral connectors. Nel Pretech is seeing an uptick of these parts coming from medical device manufacturers as they implement the new standards in their designs. The new dimensional requirements for luers are strict and we are assisting manufacturers in their compliance. We are able to accomplish their luer dimensional inspection projects and get their products to market quickly. This is crucial in the medical world as the health and well-being of patients is considered.

Changes found in ISO 80369-7: 2021 compared to the previous version ISO 80369-7: 2016 are as follows:

  • Tolerances of several reference connector dimensions are increased to facilitate easier manufacturing and certification. Most of the affected tolerances are for features that do not contact the test connector and therefore do not affect the test results. The angle tolerance for the bearing side of the threads do contact the connector under test but the change in the tolerance is considered likely have minimal to no effect on test outcomes. [1]
  • Some requirements for Luer connectors have been separated for semi-rigid materials and rigid materials to better ensure compatibility at the extreme of the design space. Definitions of semi-rigid material and rigid material have been added. [1]
  • The distance from the tip of the connector to the bottom of the first complete thread profile of the internal thread (t dimension) has been made an auxiliary dimension due to the difficulty in its measurement. The functional impact of the dimension is evaluated with the resistance to separation (from axial load) functional test. [1]
  • The N1 and N2 dimensions of the female Luer lock connector variant A (with lugs at right angle to axis) have been changed to allow measurement from the open end of the connector, to better ensure compatibility at the extreme of the design space. [1]

[1] https://www.iso.org/obp/ui/#iso:std:iso:80369:-7:ed-2:v1:en