In January 2021, ISO 10993-23:2021 Biological evaluation of medical devices – Tests for irritation was published. The new standard specifies the procedure for the assessment of medical devices and their constituent materials with regard to their potential to produce skin irritation and includes an important test model with regard to animal welfare.

Until this new standard was published, ISO 10993-10 Biological evaluation of medical devices - Part 10: Tests for irritation and skin sensitization was applied to assess skin irritation for medical devices, in vivo. ISO 10993-23:2021 technically replaces the skin irritation test from Part 10, by outlining both the well-established animal irritation test model, along with a laboratory grown human skin model as a validated alternative to predict and classify the irritation potential of medical devices, materials or their extracts according to ISO 10993-1 and ISO 10993-2.

The remarkable part here is the recognition of an in vitro irritation model. This test system uses a reconstructed human epidermis model (RhE) and provides a recognized alternative to in vivo irritation testing. Even though this is not a new procedure, the incorporation into an international standard is an important step in reducing animal testing in the development and clinical evaluation of medical devices. New methods in general have a hard time being accepted for regulatory use before inclusion into ISO 10993, so the recognition of ISO 10993-23:2021 as an important step to get away from animal testing is eagerly awaited.