173.50—Polyvinylpolypyrrolidone.
The food additive polyvinylpoly-pyrrolidone may be safely used in accordance with the following prescribed conditions:
(a)
The additive is a homopolymer of purified vinylpyrrolidone catalytically produced under conditions producing polymerization and cross-linking such that an insoluble polymer is produced.
(b)
The food additive is so processed that when the finished polymer is refluxed for 3 hours with water, 5 percent acetic acid, and 50 percent alcohol, no more than 50 parts per million of extractables is obtained with each solvent.
(c)
It is used or intended for use as a clarifying agent in beverages and vinegar, followed by removal with filtration.