Editorial Note on Part 172
Editorial Note: Nomenclature changes to part 172 appear at 61 FR 14482, Apr. 2, 1996; 66 FR 56035, Nov. 6, 2001; 66 FR 66742, Dec. 27, 2001; 68 FR 15355, Mar. 31, 2003; 70 FR 40880, July 15, 2005; 70 FR 67651, Nov. 8, 2005; 70 FR 72074, Dec. 1, 2005; and 81 FR 49896, July 29, 2016.

§ 172.167 Silver nitrate and hydrogen peroxide solution. An aqueous solution containing a mixture of silver nitrate and hydrogen peroxide may be safely used in accordance with the following prescribed conditions: ( a ) The additive is used as an antimicrobial agent in bottled water.
( b ) Hydrogen peroxide meets the specifications of the Food Chemicals Codex, 7th ed. (2010), pp. 496-497, which is incorporated by reference. The Director of the Office of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies from the United States Pharmacopeial Convention, 12601 Twinbrook Pkwy., Rockville, MD 20852 (Internet address *http://www.usp.org*). Copies may be examined at the Dockets Management Staff (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852, 240-402-7500, between 9 a.m. and 4 p.m., Monday through Friday, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to: *http://www.archives.gov/federal-register/cfr/ibr-locations.html .*
( c ) The amount of silver added will not exceed 17 micrograms per kilogram in the treated bottled water, and the amount of hydrogen peroxide will not exceed 23 milligrams per kilogram in the treated bottled water. Analyses for silver and hydrogen peroxide shall be conducted on samples of treated bottled water at the site of bottling, using samples of the water intended for treatment for the blank determination.
( d ) ( 1 ) The amount of silver in the treated bottled water is determined using the method for silver designated in 21 CFR 165.110(b)(4)(iii)(G)( 2 )( i ).
( 2 ) The amount of hydrogen peroxide in the treated bottled water is determined using a Hydrogen Peroxide Test Kit from the HACH Co., or equivalent. The manual from the Hydrogen Peroxide Test Kit, Model HYP-1, Catalog Number 22917-00, 1991, is incorporated by reference. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain copies of the test kit manual from the HACH Co., P.O. Box 389, Loveland CO, 80359 (1-800-227-4224), Model HYP-1, Catalog Number 22917-00. Copies may be examined at the Dockets Management Staff (HFA-305), Food and Drug Administration, 5630 Fishers Lane, Rm. 1061, Rockville, MD 20852, 240-402-7500, between 9 a.m. and 4 p.m., Monday through Friday, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030 or go to: *http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .*
( e ) Substances generally recognized as safe in or on food may be used to stabilize the additive to ensure that the additive will perform its intended technical effect.
( f ) The additive may not be added to bottled water that has been filtered or is intended to be filtered through a silver-containing water filter.
( g ) Bottled water must meet the quality standards for bottled water in § 165.110(b)(2) through (b)(5) of this chapter, including the limits specified for total silver and nitrate, unless the water bears a label statement of substandard quality, as provided for under § 165.110(c) of this chapter.
[74 FR 11478, Mar. 18, 2009, as amended at 78 FR 71461, Nov. 29, 2013; 81 FR 5591, Feb. 3, 2016; 88 FR 17719, Mar. 24, 2023]