ISO 7562:1990 PDF

Overview

ISO 7562:1990 - "Potatoes - Guidelines for storage in artificially ventilated stores" provides practical, internationally harmonized guidance for storing potatoes in mechanically ventilated warehouses. The standard covers pre-storage preparation, building and equipment requirements, staged storage procedures, ventilation and environmental control, inspection routines, and record-keeping for lots. It is intended for temperate climates and addresses seed, table (consumption) and processing potatoes.

Key topics and technical requirements

• Storage environment and building

  • External walls and roofs must be thermally insulated and airtight; a moisture barrier should be placed on the warm side of walls to reduce vapor penetration.
  • Minimum clearance of 1 m between the roof and the top of potato heaps or containers.

• Equipment and preparation

  • Stores should have loading/unloading/transport systems, ventilation and temperature/humidity control, electrical supply (lighting and power) and graders (calibreuses).
  • Premises must be cleaned and disinfected with officially approved chemicals before storage.

• Storage phases and conditions

  • Five storage phases are identified including drying, tuber maturation and wound healing, and cooling.
  • Maturation/wound healing: about 2 weeks after entry; recommended air temp 12–18 °C with relative humidity 90–95 %.
  • General relative humidity: 85–95 %.
  • Temperature targets vary by use:
    • Seed potatoes: preparation stage to stimulate germination - raise to 10–15 °C over 3–5 weeks with RH 75–80 % and minimum lighting ≈ 75 lx; long-term storage temperature later maintained 2–4 °C.
    • Table potatoes (consumption): long-term storage target 4–6 °C (elsewhere noted raising to 12 °C for conditioning), depending on stage.
    • Processing potatoes: storage typically 6–10 °C, with conditioning at 15–18 °C if high sugars/dark colour need correction.

• Ventilation rules

  • Use interior air, exterior air or a mix. Exterior air may be used only if outside temperature is at least 2 °C lower than inside.
  • Ventilation must limit top-to-bottom temperature differences to ≤ 1 °C.
  • Before ventilation measure temperature at minimum two points (top and bottom) and outside temperature; stop introducing external air if required; introduced air temperature should not be below 0 °C.

• Inspection and documentation

  • Regular visual and equipment checks; remove locally rotting tubers immediately.
  • Lot documentation should record: lot number, quality, variety and destination, producer name, storage date, inspection dates and temperature/humidity readings, remarks and sampling data.

Applications and users

Who benefits:

• Potato growers and seed producers
• Bulk storage warehouse operators and designers
• Processors and packers managing raw-material quality
• Agricultural extension services and post‑harvest engineers

Practical uses:

• Designing or retrofitting ventilated potato stores
• Establishing operational SOPs for temperature/humidity control and ventilation
• Training staff on inspection, lot traceability and quality maintenance

Related standards

ISO 7562 was developed by ISO/TC 34 (Agricultural food products). For complete post-harvest management, users typically consult other ISO and national standards on agricultural storage, hygiene and commodity-specific handling published by the same technical committee.