BS ISO BRITISH STANDARD 418:2001 Photography Processing chemicals- Specifications for anhydrous sodium sulfite ICS 37.040.30 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTEDBY COPYRIGHT LAW BS ISO 418:2001 National foreword This British Standard reproduces verbatim IS0 418:2001 and implements it as the UK national standard.It supersedes BS ISO 418:1994 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee CPW/42, Photography, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled "International Standards Correspondence Index", or by using the “Find" facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not ofitself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 7 and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. This British Standard, having been prepared under the direction of the Consumer Products and Services Policy and Strategy Committee, was published under the authority Amendments issued sincepublication of the Standards Policy and Strategy Committee on Amd. No. Date 25January2002 Comments CBSI 25 January 2002 ISBN 058037506 4 ISO INTERNATIONAL STANDARD 418 Third edition 2001-12-15 Photography Processing chemicals - Specifications for anhydrous sodium sulfite Photographie-Produitschimiquesdetraitement-Specifications relatives au sulfite de sodium anhydre Reference number ISO 418:2001(E) SO = ISO418:2001(E) Contents Page Foreword. Introduction 1 Scope. 2 Normativereferences.. : General.. 3.1 Physical properties.. 3.2 Hazardous properties 3.3 Storage 4 Requirements 5 Reagentsandglassware 2 6 Sampling. 7 Test methods 2 7.1 Assay 2 7.2 Massfraction of insoluble matter(as aprecipitate of calcium,magnesium and ammonium hydroxides)... 5 7.3 Massfractionofheavymetals 7.4 Mass fraction of iron. 5 7.5 Alkalinity (asNa2CO3), 7.6 Reaction to ammoniacal silver nitrate.. 7.7 Massfractionofthiosulfate(asNa2S2O3). 6 7.8 Appearance of solution. Table1—Summaryof requirements ili ISO418:2001(E) Foreword IsO (the International Organization for Standardization) is a worldwide federation of national standards bodies committees. Each member body interested in a subject for which a technical committee has been established has 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. Attention is drawn to the possibility that some of the elements of this International Standard may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. InternationalStandardISO418waspreparedbyTechnical CommitteeISO/TC42,Photography This third edition cancels and replaces the second edition (isO 418:1994), of which it constitutes a technical revision. iv ISO 418:2001(E) Introduction This International Standard is one of a series that establishes criteria of purity for chemicals used in processing ISO10