subchapter_subject: "FOOD FOR HUMAN CONSUMPTION (CONTINUED)"
part_code: "184"
part_subject: "DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE"
subpart_code: "B"
subpart_subject: "Listing of Specific Substances Affirmed as GRAS"
section_number: "184.1769a"
section_subject: "Sodium metasilicate."
cfr_reference: "21 CFR 184.1769a"
title_name: "Title 21"
title_subject: "Food and Drugs"
parts_covered: "Parts 170 to 199"
revised_date: "Revised as of April 1, 2019"
publication_date: "As of April 1, 2019"
contains_description: "Containing a codification of documents of general applicability and future effect"
publication_info: "Published by the Office of the Federal Register National Archives and Records Administration as a Special Edition of the Federal Register"
---
(a)Sodium metasilicate (CAS Reg. No. 6834-92-0) is a strongly alkaline white powder. It does not occur naturally but rather is synthesized by melting sand with sodium carbonate at 1400 °C. The commercially available forms of sodium metasilicate are the anhydrous form (Na2SiO3), the pentahydrate (Na2SiO3·5H2O), and the nonahydrate (Na2SiO3·9H2O).
(b)The ingredient must be of a purity suitable for its intended use.
(c)In accordance with § 184.1(b)(1), the ingredient is used in food with no limitation other than current good manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human food ingredient is based upon the following current good manufacturing practice conditions of use:
(1)The ingredient is used as a processing aid as defined in § 170.3(o)(24) of this chapter.
(2)The ingredient is used to treat the following foods at levels not to exceed current good manufacturing practice: for use in washing and lye peeling of fruits, vegetables, and nuts when used in accordance with § 173.315 of this chapter; for use as a denuding agent in tripe; for use as a hog scald agent in removing hair; and for use as a corrosion preventative in canned and bottled water when used in accordance with § 165.110 of this chapter.
(d)Prior sanctions for this ingredient different from the uses established in this section do not exist or have been waived.