[Code of Federal Regulations]
[Title 21, Volume 6]
[Revised as of April 1, 2007]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR573.870]

[Page 525]
 
                        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 
 
                     Subpart B_Food Additive Listing
 
Sec.  573.870  Poly(2-vinylpyridine-co-styrene).

    The food additive poly(2-vinylpyridine-co-styrene) may be safely 
used as nutrient protectant in feed for beef cattle and dairy cattle and 
replacement dairy heifers when used in accordance with the following 
conditions:
    (a) The additive meets the following specifications:

------------------------------------------------------------------------
            Component/property                       Limitation
------------------------------------------------------------------------
Inherent viscosity........................  1.0-1.6 deciliter per
                                             gram.\1\
Styrene moiety............................  40 percent maximum.
2-Vinylpyridine moiety....................  90 percent maximum.
Residual styrene..........................  200 parts per billion
                                             maximum.
Residual 2-vinylstyrene...................  200 parts per billion
                                             maximum.
Heavy metals such as lead.................  10 parts per million
                                             maximum.
Arsenic...................................  3 parts per million maximum.
------------------------------------------------------------------------
\1\ Inherent viscosity of a 0.25 percent (weight/volume) solution in
  dimethylformamide.

    (b) The additive is used in the manufacture of rumen-stable, 
abomasum-dispersible nutrient(s) for beef cattle and dairy cattle and 
replacement dairy heifers such that the maximum use of the additive from 
all sources does not exceed 5.1 grams per head per day. The additive may 
be used to protect the following nutrients:
    (1) Methionine. The resulting product must contain a maximum of 10 
percent poly(2-vinylpyridine-co-styrene) by weight and a minimum of 55 
percent methionine by weight. The coated methionine must be established 
through in vitro tests to be at least 90 percent rumen-stable, of which 
at least 90 percent is subsequently dispersible under abomasal 
conditions.
    (2) Methionine and lysine. The resulting product must contain a 
maximum of 10 percent poly(2-vinylpyridine-co-styrene) by weight and a 
minimum of a combined total of 55 percent methionine and lysine by 
weight. The coated methionine and lysine must be established through in 
vitro tests to be at least 90 percent rumen-stable, of which at least 90 
percent is subsequently dispersible under abomasal conditions.
    (c) Label and labeling. To ensure safe use of the additive, the 
label and labeling of the additive and of any feed additive supplement, 
feed additive concentrate, feed additive premix, or liquid feed 
supplement prepared therefrom, shall bear, in addition to the other 
information required by the Federal Food, Drug, and Cosmetic Act, the 
following:
    (1) The name of the additive.
    (2) A statement of the concentration of poly(2-vinylpyridine-co-
styrene) in any product or mixture.
    (3) Adequate directions for the use of the rumen-stable, abomasum-
dispersible nutrient(s) products.
    (4) The following statement: ``Warning: Maximum use of poly(2-
vinylpyridine-co-styrene) from all sources is not to exceed 5.1 grams 
per head per day.''

[57 FR 7875, Mar. 5, 1992, as amended at 57 FR 24187, June 8, 1992; 61 
FR 11547, Mar. 21, 1996; 70 FR 13100, Mar. 18, 2005]