[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.1590]

[Page 292]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 177--INDIRECT FOOD ADDITIVES: POLYMERS--Table of Contents
 
Subpart B--Substances for Use as Basic Components of Single and Repeated 
                        Use Food Contact Surfaces
 
Sec. 177.1590  Polyester elastomers.

    The polyester elastomers identified in paragraph (a) of this section 
may be safely used as the food-contact surface of articles intended for 
use in contact with bulk quantities of dry food of the type identified 
in Sec. 176.170(c) of this chapter, table 1, under Type VIII, in 
accordance with the following prescribed conditions:
    (a) For the purpose of this section, polyester elastomers are those 
produced by the ester exchange reaction when one or more of the 
following phthalates--dimethyl terephthalate, dimethyl orthophthalate, 
and dimethyl isophthalate--is made to react with alpha-hydro-
hydroxypoly (oxytetramethylene) and/or 1,4-butanediol such that the 
finished elastomer has a number average molecular weight between 20,000 
and 30,000.
    (b) Optional adjuvant substances employed in the production of the 
polyester elastomers or added thereto to impart desired technical or 
physical properties may include the following substances:

------------------------------------------------------------------------
            List of substances                       Limitations
------------------------------------------------------------------------
4,4' - Bis (alpha, alpha-dimethyl-benzyl)   For use only as an
 diphenylamine.                              antioxidant.
Tetrabutyl titanate.......................  For use only as a catalyst.
------------------------------------------------------------------------

    (c) An appropriate sample of the finished polyester elastomer in the 
form in which it contacts food when subjected to ASTM method D968-81, 
``Standard Test Methods for Abrasion Resistance of Organic Coatings by 
the Falling Abrasive Tester,'' which is incorporated by reference 
(copies may be obtained from the American Society for Testing Materials, 
1916 Race St., Philadelphia, PA 19103, or may be examined at the Office 
of the Federal Register, 800 North Capitol Street, NW., suite 700, 
Washington, DC 20408), using No. 50 emery abrasive in lieu of Ottawa 
sand, shall exhibit an abrasion coefficient of not less than 100 liters 
per mil of thickness.

[42 FR 14572, Mar. 15, 1977, as amended at 49 FR 10109, Mar. 19, 1984]