[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2006]
From the U.S. Government Printing Office via GPO Access
TITLE 21--FOOD AND DRUGS
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
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. 177.1420 Isobutylene polymers.
Isobutylene polymers may be safely used as components of articles
intended for use in producing, manufacturing, packing, processing,
preparing, treating, packaging, transporting, or holding food, in
accordance with the following prescribed conditions:
(a) For the purpose of this section, isobutylene polymers are those
produced as follows:
(1) Polyisobutylene produced by the homopolymerization of
isobutylene such that the finished polymers have a molecular weight of
750,000 (Flory) or higher.
(2) Isobutylene-isoprene copolymers produced by the copolymerization
of isobutylene with not more than 3 molar percent of isoprene such that
the finished polymers have a molecular weight of 300,000 (Flory) or
(3) Chlorinated isobutylene-isoprene copolymers produced when
isobutylene-isoprene copolymers (molecular weight 300,000 (Flory) or
higher) are modified by chlorination with not more than 1.3 weight-
percent of chlorine.
(b) The polymers identified in paragraph (a) of this section may
contain optional adjuvant substances required
in the production of the polymers. The optional adjuvant substances
required in the production of the polymers may include substances
generally recognized as safe in food, substances used in accordance with
a prior sanction or approval, and aluminum chloride.
(c) The provisions of this section are not applicable to
polyisobutylene used in food-packaging adhesives complying with Sec.
175.105 of this chapter.
Additives that reference this regulation: