Performance assessment of the Double Plate method (<scp>ISO23675</scp>) in <scp>ALT</scp>‐<scp>SPF</scp> Consortium: A highly reproducible and accurate in vitro method to determine <scp>SPF</scp>

The Double Plate method demonstrates excellent reproducibility and, following optimization, high accuracy for the SPF determination. These findings endorse the Double Plate method as a robust and ethical in vitro alternative to the in vivo reference method for SPF testing. This paved the way for its publication as a new ISO standard (ISO 23675), in December 2024, supporting consumer safety and informed product choices.