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Industry Standards & Compliance9 min readUpdated February 2026

ISPM-15 Explained: International Wood Packaging Standards

A thorough guide to ISPM-15 regulations, approved treatment methods, compliance markings, and the consequences of non-compliance for international shipments.

ISPM-15, formally known as International Standards for Phytosanitary Measures No. 15, is a set of regulations developed by the International Plant Protection Convention (IPPC) under the United Nations Food and Agriculture Organization (FAO). The standard governs the treatment of solid wood packaging materials, including pallets, crates, and dunnage, used in international trade. Its primary purpose is to prevent the global spread of invasive insects, nematodes, and plant diseases that can be carried within untreated wood across international borders. First adopted in 2002, ISPM-15 has been implemented by over 180 countries and is one of the most widely enforced phytosanitary regulations in global trade.

The standard requires that all solid wood packaging materials be debarked and treated using an approved method before being used in international commerce. The two currently approved treatment methods are heat treatment (HT), which requires the wood core temperature to reach at least 56 degrees Celsius for a minimum of 30 minutes, and dielectric heating (DH), which uses microwave or radio frequency energy to raise the core temperature to 60 degrees Celsius for one minute. Methyl bromide fumigation (MB) was previously approved but is being phased out globally due to its ozone-depleting properties and is already banned in many countries. Heat treatment has become the overwhelmingly dominant method due to its effectiveness, environmental safety, and broad acceptance.

Properly treated pallets must bear the official IPPC stamp, which serves as proof of compliance to customs authorities worldwide. The stamp includes the IPPC wheat sheaf symbol, a two-letter country code identifying the country where treatment occurred, a unique producer or treatment facility number assigned by the national plant protection organization, and the treatment code (HT for heat treatment, DH for dielectric heating). The stamp must be applied legibly on at least two opposite sides of the pallet and must be permanent (not applied via sticker or label, which could be transferred to untreated material). Only licensed and audited treatment providers are authorized to apply the IPPC stamp.

The consequences of shipping with non-compliant wood packaging can be severe and costly. Customs authorities at the destination port may refuse entry to the entire shipment, requiring it to be returned to the country of origin at the shipper's expense. Alternatively, the goods may be required to undergo treatment or repackaging at the port, causing significant delays, additional handling costs, and potential product damage. In some jurisdictions, non-compliant wood packaging must be destroyed at the importer's cost. Repeat violations can trigger enhanced scrutiny of all future shipments from the same exporter, creating ongoing delays and administrative burdens that far exceed the cost of initial compliance.

Certain materials are exempt from ISPM-15 requirements. These include processed wood products such as plywood, oriented strand board (OSB), particle board, and veneer, because the manufacturing process eliminates phytosanitary risks. Wood packaging made from pieces 6 millimeters or thinner is also exempt. Non-wood materials such as plastic, metal, and corrugated cardboard pallets are entirely outside the scope of ISPM-15. However, if even a single component of a shipping unit is constructed from solid wood exceeding 6 millimeters in thickness, the entire unit must comply with the standard. GreenCycle Pallets supplies fully ISPM-15 compliant heat-treated pallets for export, with valid IPPC stamps from our certified treatment partners.

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