The main OSB standard is: EN 300: Oriented Strand Boards (OSB) – Definitions, classification and specifications. However, all OSB products used in European construction must comply with the overall standard for wood-based panels, EN 13986: 2004+A1 2015, now updated (key amendments).
Specific information on the application of Use Classes to OSB was not included in the updated EN 335:2013 (although it did originally appear in the now withdrawn EN 335-3:1995). It is still available from APA.
EN 319: Particleboards and fibreboards – Determination of tensile strength perpendicular to the plane of the board
EN 789: Timber structures – Test methods – Determination of mechanical properties of wood-based panels
EN 1058: Wood-based panels – Determination of characteristic 5 percentile values and characteristic mean values
EN 12369-1: Wood-based Panels – Characteristic Value for Structural Design – OSB, particleboard and fibreboards
EN 12871: Wood-based panels – Performance specifications and requirements for load bearing boards for use in floors, walls and roofs
CEN/TS 12872: Wood-based panels – Guidance on the use of load-bearing boards in floors, walls and roofs