EN 813 relates to personal fall protection equipment (sit harnesses).
EN 813 - PERSONAL FALL PROTECTION EQUIPMENT - SIT HARNESSES
EN 813 explained
Sit harnesses are subjected to a drop test to generate a shock load on the product.
A lesser force is applied to the sit harness attachment point compared with fall arrest harness attachments. Sit harnesses are tested with a 2-metre drop using the maximum rated load dummy and they are required to safely arrest the fall following the drop.