[Code of Federal Regulations] [Title 7, Volume 6] [Revised as of January 1, 2008] From the U.S. Government Printing Office via GPO Access [CITE: 7CFR520.2] [Page 392] TITLE 7--AGRICULTURE CHAPTER V--AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF AGRICULTURE PART 520_PROCEDURES FOR IMPLEMENTING NATIONAL ENVIRONMENTAL POLICY ACT--Table of Contents Sec. 520.2 Definition. Control Agents mean biological material or chemicals which are intended to enhance the production efficiency of an agricultural crop or animal such as through elimination of a pest.