1、 ANSI/AWWA B303-10 (Revision of ANSI/AWWA B303-05) AWWA Standard Effective date: Dec. 1, 2010. First edition approved by AWWA Board of Directors June 1, 1967. This edition approved June 20, 2010. Approved by American National Standards Institute Oct. 25, 2010. 6666 West Quincy Avenue Advocacy Denver
2、, CO 80235-3098 Communications T 800.926.7337 Conferences www.awwa.org Education and TrainingScience and TechnologySections The Authoritative Resource on Safe WaterSodium Chlorite Copyright 2011 American Water Works Association. All Rights Reserved. ii AWWA Standard This document is an American Wate
3、r Works Association (AWWA) standard. It is not a specification. AWWA standards describe minimum requirements and do not contain all of the engineering and administrative information normally contained in specifi- cations. The AWWA standards usually contain options that must be evaluated by the user
4、of the standard. Until each optional feature is specified by the user, the product or service is not fully defined. AWWA publication of a standard does not constitute endorsement of any product or product type, nor does AWWA test, certify, or approve any product. The use of AWWA standards is entirel
5、y voluntary. This standard does not supersede or take precedence over or displace any applicable law, regulation, or codes of any governmental authority. AWWA standards are intended to represent a consensus of the water supply industry that the product described will provide satisfactory service. Wh
6、en AWWA revises or withdraws this standard, an official notice of action will be placed on the first page of the classified advertising section of Journal AWWA. The action becomes effective on the first day of the month following the month of Journal AWWA publication of the official notice. American
7、 National Standard An American National Standard implies a consensus of those substantially concerned with its scope and provisions. An American National Standard is intended as a guide to aid the manufacturer, the consumer, and the general public. The existence of an American National Standard does
8、 not in any respect preclude anyone, whether that person has approved the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standard. Ameri- can National Standards are subject to periodic review, and users are cautioned to o
9、btain the latest editions. Producers of goods made in conformity with an American National Standard are encouraged to state on their own responsibility in advertising and promotional materials or on tags or labels that the goods are produced in conformity with particular American National Standards.
10、 Caution n oti Ce : The American National Standards Institute (ANSI) approval date on the front cover of this standard indicates completion of the ANSI approval process. This American National Standard may be revised or withdrawn at any time. ANSI procedures require that action be taken to reaffirm,
11、 revise, or withdraw this standard no later than five years from the date of publication. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036;
12、 (212) 642-4900, or e-mailing infoansi.org. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information or retrieval system, except in the form of brief excerpts or quotati
13、ons for review purposes, without the written permission of the publisher. Copyright 2010 by American Water Works Association Printed in USA Copyright 2011 American Water Works Association. All Rights Reserved. iii Committee Personnel The AWWA Standards Committee on Disinfectants, which developed and
14、 approved this stan- dard, had the following personnel at the time of approval: Clifford L. McLain, Chair General Interest Members M.P. Chaulk, Halifax Regional Municipality, Canada (AWWA) D.J. Gates, Citrus Heights, Calif. (AWWA) M.C. Graves, HDR Engineering, Austin, Texas (AWWA) H. Johnson, Camp D
15、resser in the aqueous form, it contains approximately 40 percent or less by weight sodium chlorite. Technical sodium chlorite is a white flaked salt with a density of approximately 56 lb/ft 3(0.90 g/cc). Some material may have a tint of orange, depending on the iron content. Sodium chlorite is stabl
16、e when sealed or in solution but can ignite in the pres- ence of organic materials. For this reason, the solution should not be allowed to dry out on floors but should be hosed down with minimum splashing. * American National Standards Institute, 25 West 43rd Street, Fourth Floor, New York, NY 10036
17、. Copyright 2011 American Water Works Association. All Rights Reserved. viii Sodium chlorite dissolves easily in water at ordinary temperatures to form a pale yellow solution. This solution is chemically stable under ordinary temperature and pressure conditions. Solutions above 2530 percent weight p
18、er weight (w/w) may crys- tallize at moderate ambient temperatures. Crystallization temperatures may vary due to solutions originating either from dilution of slurried or dried materials. Sodium chlorite used for the onsite production of chlorine dioxide for use as a disinfectant in the treatment of
19、 drinking water or for pesticidal use in processing plant- flume water, sewage treatment, slime control in paper mills, and bacteria control in oil wells requires US Environmental Protection Agency (USEPA) registration. Sodium chlorite to be sold and used for drinking water treatment must be registe
20、red under a label or labels indicating these uses. I.B. History. The original ANSI/AWWA Standard for Sodium Chlorite was prepared by Committee 7440P. The standard was approved as tentative on Jan. 25, 1965, and made a standard by the AWWA Board of Directors on June 1, 1967. The standard was designat
21、ed ANSI/AWWA B303-67. The AWWA Standards Committee on Chlorine, Chlorine Compounds, and Related Alkalies prepared the 1988 edition, which was approved on June 19, 1988. The AWWA Standards Committee on Disinfectants prepared the 1995 edition, which was approved on June 17, 1995. Subsequent editions o
22、f ANSI/AWWA B303 were approved on June 11, 2000, and Jan. 16, 2005. This edition was approved on June 20, 2010. I.C. Acceptance. In May 1985, the US Environmental Protection Agency (USEPA) entered into a cooperative agreement with a consortium led by NSF International (NSF) to develop voluntary thir
23、d-party consensus standards and a certification program for direct and indirect drinking water additives. Other members of the original consortium included the American Water Works Association Research Foundation (AwwaRF, now Water Research Foundation*) and the Conference of State Health and Environ
24、mental Managers (COSHEM). The American Water Works Association (AWWA) and the Association of State Drinking Water Administrators (ASDWA) joined later. In the United States, authority to regulate products for use in, or in contact with, drinking water rests with individual states. Local agencies may
25、choose to impose requirements more stringent than those required by the state. To evaluate the health effects of products and drinking water additives from such products, state and local agencies may use various references, including two standards developed under the * Water Research Foundation, 666
26、6 W. Quincy Avenue, Denver, CO 80235. Persons outside the United States should contact the appropriate authority having jurisdiction. Copyright 2011 American Water Works Association. All Rights Reserved. ix direction of NSF, NSF*/ANSI 60, Drinking Water Treatment ChemicalsHealth Effects, and NSF/ANS
27、I 61, Drinking Water System ComponentsHealth Effects. Various certification organizations may be involved in certifying products in accor- dance with NSF/ANSI 60. Individual states or local agencies have authority to accept or accredit certification organizations within their jurisdiction. Accredita
28、tion of certi- fication organizations may vary from jurisdiction to jurisdiction. Annex A, “Toxicology Review and Evaluation Procedures,” to NSF/ANSI 60 does not stipulate a maximum allowable level (MAL) of a contaminant for substances not regulated by a USEPA final maximum contaminant level (MCL).
29、The MALs of an unspecified list of “unregulated contaminants” are based on toxicity testing guide- lines (noncarcinogens) and risk characterization methodology (carcinogens). Use of Annex A procedures may not always be identical, depending on the certifier. ANSI/AWWA B303 addresses additives require
30、ments in Sec. 4.4.3 of the standard. The transfer of contaminants from chemicals to processed water or to residual solids is becoming a problem of greater concern. The language in Sec. 4.4.3 is a recommenda- tion only for direct additives used in the treatment of potable water to be certified by an
31、accredited certification organization in accordance with NSF/ANSI 60, Drinking Water Treatment ChemicalsHealth Effects. However, users of the standard may opt to make this certification a requirement for the product. Users of this standard should also consult the appropriate state or local agency ha
32、ving jurisdiction in order to 1. Determine additives requirements, including applicable standards. 2. Determine the status of certifications by parties offering to certify products for contact with, or treatment of, drinking water. 3. Determine current information on product certification. II. Speci
33、al Issues. II.A. Handling, Storage, and Safety Precautions. Aqueous sodium chlorite solution is shipped in stainless-steel and fiberglass tank trucks according to US Department of Transportation (DOT) regulations. The temperature in the tanks is maintained to avoid crystallization. On receipt, the p
34、urchaser should dilute the solution appropriately to prevent the crystallization of sodium chlorite. As received in loose- flake form in metal containers, sodium chlorite will tolerate some rough handling. Sodium chlorite in contact with acid will react with rapid evolution of chlorine dioxide gas.
35、When heated above 347F (175C), dry sodium chlorite will decom- pose rapidly, liberating oxygen, with the evolution of sufficient heat to make the * NSF International, 789 N. Dixboro Road, Ann Arbor, MI 48105. Copyright 2011 American Water Works Association. All Rights Reserved. x decomposition self-
36、sustaining. If the decomposition of sodium chlorite is contained, as in closed containers, the effect is explosive. Therefore, sodium chlorite should be protected at all times from exposure to heat. In case of ignition, normal firefighting equipment is relatively ineffective because sodium chlorite
37、supplies its own oxygen. The temperature of a sodium chlorite fire may exceed 3,992F (2,200C), and steam explosions may result if water is sprayed directly on burning material. Mist settings on nozzles should be used to cool burning material after the drums have been isolated. As a general rule, fla
38、mmables should be kept away from areas where oxidizing agents, such as sodium chlorite, are stored. Sodium chlorite should be stored only in an enclosed space specially prepared for this purpose. This storage area should be kept cool and should be well ventilated and fireproof. Sodium chlorite shoul
39、d be removed from the storage room only as needed for immediate use. Nonreturnable shipping contain- ers should be properly disposed of as soon as they are empty. The shipping containers should never be used for any other purpose after they are empty. Sodium chlorite is a very active, strongly oxidi
40、zing chemical that, in solid form, reacts strongly with acids, sulfur, combustibles, and organic materials, such as wood, rubber, fats, and oils. When sodium chlorite is to be removed from a drum, a clean nonmetallic scoop or vessel uncontaminated with foreign matter should be used. Dried or caked m
41、aterial should never be chipped or crushed, as ignition may result. Complete instructions for the storage and safe handling of sodium chlorite should be obtained from the manufacturer. Protective clothing should be worn when handling sodium chlorite. Plastic gloves and eye protection should be worn
42、as precautionary measures. Sodium chlorite is poi- sonous if ingested. If any sodium chlorite comes into contact with clothing or other combustible material (such as paper towels or cotton mops), spontaneous ignition may occur upon drying. The clothing or combustible material should be immediately s
43、oaked in water to remove all trace of the sodium chlorite or subsequently incinerated without delay. Refer to material safety data sheets (MSDS) available from the chemical manufacturer or supplier for additional information. III. Use of This Standard. It is the responsibility of the user of an AWWA
44、 standard to determine that the products described in that standard are suitable for use in the particular application being considered. III.A. Purchaser Options and Alternatives. The following information should be provided by the purchaser. 1. Standard usedthat is, ANSI/AWWA AWWA B303, Standard for Sodium Chlorite, of latest revision. Copyright 2011 American Water Works Association. All Rights Reserved.
