The Administrator shall perform, for and under the supervision of the Secretary, such duties as the Secretary may require in the enforcement or administration of the provisions of the Act and this part. The Administrator is authorized to waive for a limited period any particular provisions of the regulations in this part to permit experimentation so that new procedures, equipment, and processing techniques may be tested to facilitate definite improvements and at the same time to determine full compliance with the spirit and intent of the regulations in this part. The Food Safety Inspection Service and its officers and employees shall not be liable in damages through acts of commission or omission in the administration of this part.