[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR173.65]

[Page 125]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 173_SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN 
CONSUMPTION--Table of Contents
 
  Subpart A_Polymer Substances and Polymer Adjuvants for Food Treatment
 
Sec. 173.65  Divinylbenzene copolymer.

    Divinylbenzene copolymer may be used for the removal of organic 
substances from aqueous foods under the following prescribed conditions:
    (a) The copolymer is prepared in appropriate physical form and is 
derived by the polymerization of a grade of divinylbenzene which 
comprises at least 79 weight-percent divinylbenzene, 15 to 20 weight-
percent ethyl vinyl benzene, and no more than 4 weight-percent 
nonpolymerizable impurities.
    (b) In accordance with the manufacturer's directions, the copolymer 
described in paragraph (a) of this section is subjected to pre-use 
extraction with a water soluble alcohol until the level of 
divinylbenzene in the extract is less than 50 parts per billion as 
determined by a method titled, ``The Determination of Divinylbenzene in 
Alcohol Extracts of Amberlite XAD-4,'' which is incorporated by 
reference. Copies of this method are available from the Center for Food 
Safety and Applied Nutrition (HFS-200), Food and Drug Administration, 
5100 Paint Branch Pkwy., College Park, MD 20740, or available for 
inspection at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC 20408. The copolymer is then 
treated with water according to the manufacturer's recommendation to 
remove the extraction solvent to guarantee a food-grade purity of the 
resin at the time of use, in accordance with current good manufacturing 
practice.
    (c) The temperature of the aqueous food stream contacting the 
polymer is maintained at 79.4 [deg]C (175 [deg]F) or less.
    (d) The copolymer may be used in contact with food only of Types I, 
II, and VI-B (excluding carbonated beverages) described in table 1 of 
paragraph (c) of Sec. 176.170 of this chapter.

[50 FR 61, Jan. 2, 1985]