International Shipping Is Different
If your business ships products internationally from Portland — whether to Asia, Europe, or anywhere else — your packaging needs are meaningfully different from domestic shipping. International shipments face longer transit times, more handling transfers, different climate conditions, and regulatory requirements that domestic boxes never encounter.
ISPM-15 and Wood Pallets
The International Standards for Phytosanitary Measures No. 15 (ISPM-15) requires that all wood packaging materials used in international trade be heat-treated or fumigated to prevent the spread of invasive pests. This applies to pallets, crates, and dunnage.
Compliant wood must bear the IPPC stamp with the treatment code (HT for heat-treated or MB for methyl bromide). Non-compliant wood packaging can result in shipment rejection, quarantine, or destruction at the destination port.
Corrugated boxes themselves are exempt from ISPM-15 because they are processed fiber, not raw wood. But the pallets they sit on are not.
Box Strength Requirements
International shipments need stronger boxes than domestic for several reasons:
- Multiple handling transfers — Port to ship, ship to port, port to truck, truck to destination. Each transfer is a damage opportunity.
- Stacking in containers — Boxes in ocean containers are stacked under pressure for weeks. Humidity inside containers can reach 90%+, significantly weakening corrugated.
- Rough handling at ports — Automated sorting systems and heavy equipment at ports are less gentle than domestic parcel networks.
As a rule of thumb: go at least one ECT grade higher for international than you would for domestic. If 32 ECT is fine domestically, use 44 ECT for export. If 44 ECT works domestically, use 48 ECT double wall for international.
Climate Considerations
Ocean containers experience extreme temperature swings — hot during the day, cold at night. This causes "container rain" — condensation that drips onto cargo. Corrugated boxes absorb this moisture and lose strength rapidly.
Mitigation options include: desiccant packets inside containers, shrink-wrapping pallets in stretch film, using wax-coated corrugated for the outer layer, or lining the container floor with moisture-barrier material.
Used Boxes for Export
Used boxes can absolutely be used for international shipping, provided they meet the strength requirements. A used double-wall box in Grade A or B condition performs identically to a new box of the same specification. The key is selecting the right strength grade — not the right newness.