[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: 21CFR584.700]

[Page 540]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 584--FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE IN FEED AND DRINKING WATER OF ANIMALS--Table of Contents
 
       Subpart B--Listing of Specific Substances Affirmed as GRAS
 
Sec.  584.700  Hydrophobic silicas.

    (a) Product. Amorphous fumed hydrophobic silica or precipitated 
hydrophobic silica (CAS Reg. No. 68611-0944-099, silane, 
dichlorodimethyl-, reaction products with silica).
    (b) Conditions of use. An anticaking/free-flow agent in vitamin 
preparations for animal feed.
    (c) Limitations. Not to exceed 5 percent in the vitamin preparation. 
It shall be used in accordance with good manufacturing or feeding 
practices. It must be of purity suitable for intended use, and it must 
comply with the following specifications:
    (i) Amorphous fumed hydrophobic silica: Not less than 99.0 percent 
silicon dioxide after ignition. Not more than 3 ppm arsenic. Not more 
than 0.003 percent heavy metals (as lead). Not more than 10 ppm lead. 
Not more than 2.5 percent loss on drying. Not more than 2 percent loss 
on ignition after drying. Not more than 1 percent insoluble substances. 
Not more than 50 parts per million dichlorodimethylsilane.
    (ii) Precipated hydrophobic silica: Not less than 94.0 percent 
silicon dioxide after ignition. Not more than 3 ppm arsenic. Not more 
than 0.003 percent heavy metals (as lead). Not more than 10 ppm lead. 
Not more than 7 percent loss on drying. Not more than 8.5 percent loss 
on ignition after drying. Not more than 5 percent soluble ionizable 
salts (as sodium sulfate). Not more than 1 percent insoluble substances. 
Not more than 50 parts per million dichlorodimethylsilane.

[61 FR 43453, Aug. 23, 1996]