Overview
ISO 5708:1983, developed by the International Organization for Standardization (ISO), specifies requirements for the design, construction, and performance of refrigerated bulk milk tanks. These tanks are essential for maintaining the quality and freshness of milk at farms and milk collection points. The standard applies to tanks with automatic control, suitable for either fixed or mobile installations, and is specifically intended for tanks designed to handle milk for either two (24-hour) or four (48-hour) milking sessions. ISO 5708 does not address electrical safety regulations.
Key Topics
Design and Construction
- Tanks must be made from materials, especially stainless steel, that resist corrosion, are suitable for contact with milk, and comply with relevant standards.
- Inner vessels should be designed to facilitate easy cleaning and inspection, while maintaining mechanical strength for transport and daily operation.
- Surfaces must prevent milk contamination and enable effective disinfection.
Performance Requirements
- Refrigerated tanks are evaluated for their ability to maintain milk at specific temperatures, cool incoming milk within defined timeframes, and prevent ice formation or overheating.
- Agitation systems must ensure uniform temperature and fat distribution in stored milk.
- Automatic control systems are required for reliable, unattended operation.
Methods of Test
- A specific set of test methods is outlined for assessing material quality, construction integrity, control systems, measuring equipment, refrigerating equipment, and overall performance.
- Tanks must undergo standardized cooling and agitation tests to confirm compliance.
Identification and Documentation
- Each tank must have a clear identification plate detailing manufacturer information, rated volume, performance classification, and relevant technical data.
- Comprehensive instructions for installation, use, cleaning, and maintenance must be provided, supporting safe operation and product longevity.
Applications
ISO 5708:1983 is widely applied in the dairy industry, particularly for:
- Farms: Ensuring on-site bulk milk tanks maintain optimal milk quality, supporting safe storage between collections.
- Milk Collection Centers: Standardizing refrigerated storage for milk picked up from multiple suppliers.
- Equipment Manufacturers: Serving as a benchmark for developing and certifying tanks that meet international market requirements.
- Quality Control and Certification: Enabling regulatory and independent testing bodies to evaluate tanks for performance, hygiene, and safety (excluding electrical safety).
The implementation of this standard ensures that bulk milk storage equipment provides reliable cooling and hygiene, reduces spoilage, and meets global dairy market expectations.
Related Standards
Stakeholders deploying or evaluating ISO 5708 should be aware of relevant, referenced standards for complete compliance:
- ISO 683 (Part 13): Specifies grades for wrought stainless steels, essential for material selection in milk tanks.
- ISO/R 468: Describes requirements for surface roughness, supporting hygienic interior finishes.
- ISO/R 1662: Covers refrigerating plant safety requirements (excluding electrical safety covered elsewhere).
- ISO 1992 Part 2: Provides test methods for commercial refrigerated cabinets, complementing performance testing for similar applications.
- Codex Alimentarius Standards: International food standards for milk and milk products referenced for product handling and sampling.
Adhering to ISO 5708:1983 and its related standards ensures interoperability, safety, and consistent quality across the dairy supply chain, supporting producers, equipment suppliers, and regulatory bodies worldwide.
