What the classification says
Twisted blocks must not protrude more than 10 mm.
How to spot it
Sight along the long edge. A block turned so its face sticks out past the board edge by more than about 1 cm fails. Class C allows up to 1 cm; classes A and B allow none.
Why it matters
This is one of the few faults where the classification gives a number. A block that has turned under impact sticks out past the line of the boards, where it can snag on racking, conveyors and the next pallet in a stack. Up to about 1 cm of protrusion keeps a pallet in class C, which EPAL does not mark as suitable for machines or high-bay racking. Classes A and B allow no twisted blocks at all, so a single twisted block decides whether a lot can go into automated handling.
Effect on the pallet's class
Up to 1 cm: class C at best. Over about 1 cm: not fit for use. See Not fit for use for the full criteria.
Repair
Licensed repair only.
If no licensed repairer is practical, sell sound timber as non-EPAL wood or send the pallets for recycling.