ISO INTERNATIONAL STANDARD 3625 Second edition 1994-05-01 Photography Processing chemicals Specifications for potassium hydroxide Photographie - Produits chimiques pour traitement - Speécifications relatives a I'hydroxyde de potassium ISO Reference number ISO 3625:1994(E) n for Standardizatior Provided by IHS und No reproduction or networking permtted without license from IHS Not for Resale ISO 3625:1994(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO member bodies). The work of preparing International Standards is normally carried out through IsO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. ISO/TC42,Photography This: second edition cancels and replaces the first edition (lsO3625:1976),whichhasbeentechnicallyrevised. C ISO1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced microfilm, without permission in writing from the publisher. InternationalOrganizationforStandardization Case Postale 56 . CH-1211 Geneve 20 · Switzerland Printed in Switzerland Copyright Int national Organization for Standardization No reproduction or networking permited without license from IHS Not for Resale CISO ISO3625:1994(E) Introduction o.1 This International Standard is one of a series that establishes criteria of purity for chemicals used in processing photographic materials. Genera test methods and procedures cited in this International Standard are compiled in parts 1, 5, 6 and 7 of Iso 10349. This International Standard is intended for use by individuals with a work- ingknowledgeofanalyticaltechnigues,whichmaynotalwaysbethe case. Some of the procedures utilize caustic, toxic or otherwise hazardous chemicals. Safe laboratory practice for the handling of chemicals requires apparelsuchasfacemasksorapronswhereappropriate.Normalpre- hazardous materials. Hazard warnings designated by a letter enclosed in angle brackets, <>, are used as a reminder in those steps detailing hand- from the manufacturer. ments for the suitability of a photographic-grade chemical. The tests cor relate with undesirable photographic effects. Purity requirements are set as low as possible consistent with these photographic effects. These cri- teria are considered the minimum requirements necessary to assure suf- ficientpurityforuseinphotographicprocessingsolutions,exceptthatif the purity of a commonly available grade of chemical exceeds photo- graphic processing requirements and if there is no economic penalty in its use,the purityrequirements havebeen settotake advantage of the availabilityof thehigher-qualitymaterial.Everyefforthasbeenmadeto keep the number of requirements to a minimum. Inert impurities are lim- ited to amounts which will not unduly reduce the assay. All tests are per- furnished for use. Although the ultimate criterion for suitability of such a chemical is its successful performance in an appropriate use test, the shorter, more economical test methods describes in this International Standard are generally adequate. Assay procedures have been included in all cases where a satisfactory safeguard of chemical purity but also as a valuable complement to the identity test. ldentity tests have been included whenever a possibility ex- ists that another chemical or mixture of chemicals could pass the other tests. Copyright International Organization for S