ISO 419-1972 PDF
Name in English:
St ISO 419-1972
Name in Russian:
Ст ISO 419-1972
Original standard ISO 419-1972 in PDF full version. Additional info + preview on request
Full title and description
ISO 419:1972 — Photographic grade sodium thiosulphate, crystalline — Specification. This International Standard defines the chemical and physical requirements, and related testing and labelling expectations, for sodium thiosulphate supplied for photographic processing uses (fixer and related photographic chemistry applications).
Abstract
ISO 419:1972 provided a short specification for photographic-grade crystalline sodium thiosulphate, setting out purity criteria, limits on common impurities, physical characteristics of the crystalline product, and reference test methods and packaging/labelling recommendations needed to ensure suitability for photographic processing. The standard has since been withdrawn and its subject matter incorporated into a later ISO publication.
General information
- Status: Withdrawn (withdrawal recorded; subject replaced by a later ISO publication).
- Publication date: June 1972.
- Publisher: ISO (International Organization for Standardization).
- ICS / categories: 37.040.30 (Photographic chemicals).
- Edition / version: Edition 1 (1972).
- Number of pages: 3.
Key bibliographic and lifecycle details are recorded on ISO's catalogue entry for the standard.
Scope
The standard specified requirements for photographic-grade sodium thiosulphate in its crystalline form intended for photographic processing. Its scope covered compositional purity (assay), permissible levels of typical impurities and contaminants, physical characteristics such as crystalline appearance and loss on drying, and the required tests or methods to verify conformance. The standard was intended for manufacturers, suppliers and laboratories handling chemicals for photographic processing.
Key topics and requirements
- Definition of the required physical form (crystalline) and general appearance expected for photographic-grade material.
- Specification of chemical purity (assay) and permissible ranges or limits for common impurities (chlorides, sulphates, residual sulfite, heavy metals, etc.).
- Reference test methods to determine assay, loss on drying, residue and impurity levels.
- Packaging, labelling and storage guidance appropriate for photographic processing chemicals.
- Requirements intended to ensure reproducible performance when used as a fixing agent in photographic development processes.
Typical use and users
Primary users were photographic chemical manufacturers and suppliers, photographic laboratories, quality control and analytical chemistry laboratories, and standards bodies involved in photographic materials and conservation. The specification supported procurement and acceptance testing of sodium thiosulphate for use as a photographic fixer and related processing chemicals.
Related standards
ISO 419:1972 was later withdrawn and its subject matter was taken into account when ISO published subsequent standards covering sodium thiosulfate and other photographic processing chemicals; ISO 10636 (published 1994) is recorded as a successor/replacement covering related material. The standard sits within ISO/TC 42 (Photography) publications that also include specifications for other photographic chemicals (for example ISO 418 / ISO 420 and related photographic processing chemical specifications).
Keywords
ISO 419, 1972, sodium thiosulphate, sodium thiosulfate, crystalline, photographic chemicals, fixer, purity specification, photographic processing, ISO/TC 42.
FAQ
Q: What is this standard?
A: ISO 419:1972 is an International Standard titled "Photographic grade sodium thiosulphate, crystalline — Specification" that defined minimum chemical and physical requirements for sodium thiosulphate intended for photographic use.
Q: What does it cover?
A: It covered the identity and physical form of photographic-grade sodium thiosulphate, criteria for chemical purity and permissible impurities, basic test methods for verification, and guidance on packaging and labelling for photographic processing applications.
Q: Who typically uses it?
A: Chemical manufacturers and suppliers of photographic reagents, photographic processing laboratories, QC/analytical labs, conservators and standards bodies concerned with photographic materials would have used the standard for specification and acceptance testing.
Q: Is it current or superseded?
A: ISO 419:1972 has been withdrawn. Its subject matter was superseded by later ISO work; ISO records show ISO 10636:1994 as a later related publication addressing sodium thiosulfate specifications. A recorded withdrawal action for ISO 419 occurred in the 1990s.
Q: Is it part of a series?
A: Yes — it is part of the ISO photographic processing chemicals set of standards maintained under ISO/TC 42. Other related standards address different photographic processing chemicals (for example standards dealing with sodium sulfite and potassium bromide).
Q: What are the key keywords?
A: Sodium thiosulphate, sodium thiosulfate, photographic chemicals, fixer, crystalline, purity specification, ISO 419, ISO/TC 42, withdrawn, ISO 10636.