ISO 18917 pdf download.Photography — Determination of residual thiosulfate and other related chemicals in processed photographic materials — Methods using iodine-amylose, methylene blue and silver sulfide
1 Scope
1.1 This International Standard specifies test methods for the determination of residual thiosulfate and other related chemicals in processed photographic materials. 1.2 This International Standard applies to silver halide/gelatin products that have been processed with a final thiosulfate fixing bath and a water wash. This International Standard does not apply to stabilised black-and-white products, thermally processed films, or instant-type products. The procedures given in this International Standard measure residual thiosulfate, and the silver densitometric method measures residual related polythionate materials as well. Measurements carried out by the procedures in this International Standard may, within the limitations stated in annexes A and B, correlate with the image stabilities of processed photographs. 1.3 Film or plates with photographic-sensitive layers on both sides, or with a photographic sensitive layer on one side and a gelatin backing layer on the reverse side, may contain approximately twice as much thiosulfate after processing as samples having a coating on one side only. This situation will be true for materials for which residual thiosulfate is determined by the iodine-amylose or methylene blue procedures. NOTE For the method of reporting such results, see figure 1 , example 2. 1.4 The iodine-amylose can be used with fibre-based paper, resin-coated paper, films and plates. It is the method to be used with films and papers containing incorporated developing agents. 1.5 The methylene blue method can be used with fibre-based paper, resin-coated paper, films and plates but not with films and paper containing incorporated developing agents. 1.6 The silver sulfide densitometric method measures thiosulfates, polythionates and all other residual chemicals in a processed product that react with silver ion to form a silver “stain” under the conditions of the test. 1.7 A tabulated summary of methods, scope, etc. is given in annex B.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards . ISO 5-3:1 995, Photography — Density measurements — Part 3: Spectral conditions. ISO 1 0349-1 :1 992, Photography — Photographic-grade chemicals — Test methods — Part 1 : General.
3 General requirements
3.1 Safety and hazard concerns 3.1.1 Handling Reagents shall be handled in conformity with health and safety precautions as shown on containers or as given in other sources of such information. Proper labelling of prepared reagents includes chemical name, date of preparation, expiration date, restandardization date, name of preparer, and adequate health and safety precautions. The discharge of reagents shall conform to applicable environmental regulations. 3.1.2 Hazard warnings Some of the chemicals specified in the test procedures are caustic, toxic or otherwise hazardous. Safe laboratory practice for the handling of chemicals requires the use of safety glasses or goggles, rubber gloves and other protective apparel such as face masks or aprons where appropriate. Specific danger notices are given in the text for particularly dangerous materials, but normal precautions are required during the performance of any chemical procedure at all times.Employers shall provide training and health and safety information in conformance with legal requirements. The hazard symbol system used in this International Standard is intended to provide information to the users and is not meant for compliance with legal requirements for labelling, as these vary from country to country. It is strongly recommended that anyone using these chemicals obtain from the manufacturer pertinent information about the hazards, handling, use and disposal of these chemicals.