The Administrator shall perform, for and under the supervision of the Secretary, such duties as are prescribed in the regulations in this part and as the Secretary may require in the administration of the regulations in this part. The Administrator is authorized to waive for limited periods any particular provisions of the regulations to permit experimentation so that new procedures, equipment, and processing techniques may be tested to facilitate definite improvements and, at the same time, to assure full compliance with the spirit and intent of the regulations. The Food Safety and 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.