Overview
ISO 7431-2:2024 specifies detailed requirements and specifications for thiourea used in industrial applications. This international standard defines three distinct classes of thiourea based on purity and content suitable for various industrial uses. It also covers marking, packaging, transport, and storage practices to ensure safety, quality, and compliance with regulatory guidelines.
Thiourea (CAS No. 62-56-6) is a white crystalline powder widely used in manufacturing pharmaceuticals, dyes, resins, rubber vulcanization accelerators, and flotation agents for metallurgical processes. This standard ensures consistent quality and safety practices for users handling thiourea in different industrial sectors.
Key Topics
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Classification and Quality Requirements
- Defines Class I, Class II, and Class III thiourea, each with specific purity and contaminant limits.
- Class I-high purity (>99.5%) for optical, electronic, and new energy materials.
- Class II and III-suitable for general chemical industries including printing, dyeing, pharmaceuticals, pesticides, and mineral processing.
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Chemical and Physical Characteristics
- Purity standards including thiourea content, water-insoluble substances, ignition residue, melting point, turbidity, thiocyanate content, and allowable heavy metals.
- Visual inspection confirms the powder’s white crystalline appearance.
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Marking and Labeling
- Mandatory information like product name, class, manufacturer details, lot number, weight, and reference to ISO 7431-2:2024.
- Includes specific hazard labeling covering toxicity and environmental risks according to the Globally Harmonized System (GHS).
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Packaging, Transport, and Storage
- Requires double sealed packaging with chemically inert inner bags and robust outer containers.
- Storage conditions to maintain material integrity: cool, dry, ventilated environments, protection from sunlight, moisture, fire, and contamination.
Applications
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Pharmaceutical Production
As an intermediate in drug manufacturing, high-grade Class I thiourea ensures purity critical for sensitive chemical syntheses.
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Dye and Resin Manufacturing
Widely used in creating colorants and resin precursors where controlled standardized chemical quality prevents defects.
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Rubber Industry
Functions as an efficient vulcanization accelerator improving rubber elasticity and durability.
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Mineral Processing
Applied as a flotation agent to extract valuable metals by selectively separating ore particles.
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Optical and Electronic Materials
Class I thiourea’s high purity supports innovations in optical fibers, electronics components, and new energy technologies.
Industrial users benefit from the standardized quality assurance that ISO 7431-2:2024 delivers, optimizing product performance while ensuring safety compliance.
Related Standards
- ISO 7431-1:2024, Thiourea for industrial use - Test methods, which details the analytical procedures for verifying quality characteristics of thiourea.
- ISO 780, Packaging - Graphical symbols for handling and storage, which includes standardized marking symbols used on thiourea packaging to indicate hazards and handling.
- United Nations GHS Rev. 9 (2021), Globally Harmonized System of Classification and Labelling of Chemicals, guiding classification of chemical hazards and label requirements.
These standards collectively support safe handling, consistent quality, and global trade compliance for industrial thiourea products.
Adhering to ISO 7431-2:2024 allows manufacturers, distributors, and users of thiourea to ensure product integrity, maintain workplace safety, and foster environmental responsibility in industrial applications. For comprehensive quality control and regulatory conformity, referencing this standard is essential in chemical industrial processes involving thiourea.
