1. If the particle size of the animal by-products to be rendered is more than 20 millimetres, the animal by-products shall be reduced in size using equipment specified in the licence, set so that the particle size after reduction is no greater than 20 millimetres or such smaller size as the licence shall specify. The effectiveness of the equipment shall be checked daily and its condition recorded. If checks disclose the existence of particles larger than is permitted in the licence, the process shall be stopped and repairs made before the process is resumed.