[Code of Federal Regulations] [Title 21, Volume 6] [Revised as of January 1, 2003] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR573.340] [Page 501-502] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 573--FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS--Table of Contents Subpart B--Food Additive Listing Sec. 573.340 Diatomaceous earth. (a) Identity. The additive consists of siliceous skeletal material derived from various species of diatoms. (b) Specifications. The additive shall conform to the following specifications: Lead, not more than 15 parts per million. Arsenic (as As), not more than 20 parts per million Fluorine, not more than 600 parts per million. [[Page 502]] (c) Uses. It is used or intended for use as an inert carrier or anticaking agent in animal feeds in an amount not to exceed 2 percent by weight of the total ration.