Containers used for transporting export perishable products must be absolutely clean to ensure food safety and must maintain optimum temperature and atmosphere conditions to minimize product quality loss. Every aspect of the container handling chain must focus on these two basic requirements. More details are documented in the PPECB Quality Management System (QMS).
1. Requirements for Container Handling Depots
National and international food safety and traceability legislation, as well as Good Distribution Practices (GDP), are being instituted by the retail trade. These requirements and procedures demand that all operations associated with the handling and distribution of perishable and food products comply with approved standards and are open to external auditing.
There are two basic international requirements for the transport of perishable products:
- Prevention of the distribution of quarantine pests
- Protection of cargo against contamination
Key aspects needing attention:
1.1 Stacking Areas
- Storage areas for containers (before and after use) must be well-drained and level.
- Areas must be clean and protected from pollution (chemicals, water, dust).
- A solid or crushed stone (gravel) surface without potholes is a minimum requirement.
1.2 Stacking Heights
- Worker safety is paramount and dictates stacking heights.
- Single stacking is important for pre-trip procedures, pre-trip inspection (PTI), and cleanliness inspection.
1.3 Repair Bays
- All working areas must comply with national safety requirements.
- Areas must have a concrete floor and be under cover to prevent contamination of exposed insulation.
1.4 Wash Bays
- Must have a sloped, solid, and permanent surface to allow all wash water to drain away from the container and washing area.
- Wash water must be handled according to local authority rules to avoid environmental pollution.
2. Depot Quality Management Systems
Consumers and international trade are increasingly demanding regarding product quality, food safety, and costs. Due diligence is a basic requirement, and everyone in the food handling and supply chain must accept responsibility for their actions. The only way to comply is to implement and apply a quality management system.
Key aspects to address:
2.1 In-House Quality Control
- All depots handling and preparing containers for export must maintain a documented in-house quality control system.
- Personnel must be well-trained, and accurate records of all actions must be kept.
- The system must be audited internally and externally by trained personnel and accredited auditors.
- The system should identify and minimize risk areas, demonstrate due diligence, ensure correct container functioning, food safety, and support traceability.
- A thorough container inspection must be done when a used container is delivered to the depot, focusing on:
- Hygiene condition of the container
- Container structure
- Condition of the cooling unit
2.2 Food Safety Requirements
Food safety requirements are highlighted in Chapter 1, paragraph 3.1. Authorities of importing countries may stop all imports if there is any suspicion that the product is unsafe or unfit for human consumption. The three basic food safety hazards are biological, chemical, and physical contamination. Management systems must ensure:
- Biological cleanliness: Free from insects, bacteria, fungal spores, and any material that may host contaminants. Correct washing and cleaning procedures must be followed, and all surfaces (including air handling systems) must be sterilized. Avoid recontamination after cleaning.
- Chemical cleanliness: Free from traces of chemicals, taints, odors, or substances that may cause chemical contamination. Only approved detergents, sealing compounds, repair materials, and methods must be used.
- Physical cleanliness: Free from objects such as sand, dust, glass, screws, nails, pop rivets, bolts, nuts, or any object (even minute) that may get into or onto the product. This also applies to the cooling unit and air ducting.
2.3 Traceability Requirements
Traceability is the ability to quickly and correctly trace the origin, handling, storage, transport, and distribution pathways of a product. In the container transport context, this means:
- The identification of the container must be known and linked to the consignment at all times.
- The history of the container (previous cargoes, destinations, cleaning, repair, inspection records, storage, transport conditions, or any other factor affecting the product) must be known and documented.
- Accurate and detailed records must be available to the exporter, importer, and authorities for each specific container.
3. Preparation of Integral Refrigerated Containers
The in-house quality control system must identify all structural and mechanical defects and ensure all containers are correctly prepared for perishable products. All containers must have a valid ISO (Paris) registered identification number and a valid safety certificate (CSC plate).
3.1 Structural Maintenance and Repairs
All containers must be inspected for structural and physical defects:
- The container frame must be sound and rust-free.
- External side panels must be dry and may not bulge more than 40 mm beyond the steel framework. All joints must be intact and properly sealed.
- Roof sagging and floor bulging must not exceed 25% (or hinder loading); all joints must be intact, sealed, and watertight.
- Doors must not be damaged; hinges and closing mechanisms must operate freely; door seals must be intact and provide an airtight seal.
- Internal side panels must be intact and securely bonded to the insulation. International recommendation: delamination should not exceed 1 m² per side panel (some shipping lines allow up to 25% of the total area per side if insulation is dry).
- No internal bulging, sharp edges, loose panels, or cargo fixing devices should be present.
- The T-bar floor must not be damaged; all joints (especially at the door) must be intact; no floor movement during loading.
- Insulation must be intact and dry. Damaged insulation must be replaced with the same specification.
- All repairs must be made by trained personnel using internationally approved materials and methods. Materials that may give off taints must not be used.
- Repairs and maintenance must be completed and documented before moving the container to the washing bay.
3.2 Cooling Unit – Maintenance and Repairs
All refrigeration units must be inspected for defects, accuracy of control and recording systems, and necessary repairs/adjustments:
- Visual check for damage (loose components, damaged cables/wiring).
- Motor and compressor checked for smooth operation and overheating.
- Oil and gas levels checked and adjusted if necessary.
- Air circulating fans (condenser and evaporator) must operate correctly, without abnormal noise, and with correct airflow direction.
- Thermostat temperature controller must be accurately calibrated (±0.5°C from set point). Chill mode is controlled on delivery air; frozen mode on return air.
- Sensors for delivery (DAT) and return (RAT) air temperature must be accurately calibrated and functioning.
- Defrost system must be operational; drain pipe open.
- All indicator lights, fuses, backup batteries, etc., must be functional.
- Fresh air ventilation valve must be easy to operate and functioning.
- Air ducts must be unobstructed and clean.
All maintenance must be carried out by qualified personnel to the container owner’s specification. Only specified and approved materials, spares, and components may be used.
3.3 Cleaning of Containers
Containers must be thoroughly cleaned after every load. Each depot must follow its own cleaning protocols, but the following are essential:
- Well-designed and constructed wash bays are required, with a solid sloped surface for fast draining. The container must be positioned with the door in the lower position.
- All dry material (dust, packaging remains) must be swept or vacuumed.
- All stains must be removed before washing.
- The inside must be thoroughly cleaned (methods include steam cleaning, high-pressure water jets). Only approved and registered detergents may be used.
- All free water, especially in the T-bar floor, must be removed (preferably with high-pressure air).