[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 C_Substances for Use Only as Components of Articles Intended for
Sec. 177.2250 Filters, microporous polymeric.
Microporous polymeric filters identified in paragraph (a) of this
section may be safely used, subject to the provisions of this section,
to remove particles of insoluble matter in producing, manufacturing,
processing, and preparing bulk quantities of liquid food.
(a) Microporous polymeric filters consist of a suitably permeable,
continuous, polymeric matrix of polyvinyl chloride, vinyl chloride-
propylene, or vinyl chloride-vinyl acetate, in which
finely divided silicon dioxide is embedded. Cyclohexanone may be used as
a solvent in the production of the filters.
(b) Any substance employed in the production of microporous
polymeric filters that is the subject of a regulation in parts 170
through 189 of this chapter must conform with any specification in such
(c) Cyclohexanone when used as a solvent in the production of the
filters shall not exceed 0.35 percent by weight of the microporous
(d) The microporous polymeric filters may be colored with colorants
used in accordance with Sec. 178.3297 of this chapter.
(e) The temperature of food being processed through the microporous
polymeric filters shall not exceed 180 [deg]F.
(f) The microporous polymeric filters shall be maintained in a
sanitary manner in accordance with good manufacturing practice so as to
prevent potential microbial adulteration of the food.
(g) To assure safe use of the microporous polymeric filters, the
label or labeling shall include adequate directions for a pre-use
treatment, consisting of washing with a minimum of 2 gallons of potable
water at a temperature of 180 [deg]F for each square foot of filter,
prior to the filter's first use in contact with food.
[42 FR 14572, Mar. 15, 1977, as amended at 56 FR 42933, Aug. 30, 1991]
Additives that reference this regulation: