International trade moves on wooden pallets, and those pallets must comply with a global standard known as ISPM-15 before they can cross most national borders. The International Standard for Phytosanitary Measures No. 15, administered by the International Plant Protection Convention (IPPC), requires that all solid wood packaging materials used in international commerce be treated to eliminate pests that could threaten agriculture and ecosystems in the importing country.
For the majority of exporters, heat treatment (HT) is the preferred compliance method. It is universally accepted, environmentally friendly, and straightforward to implement when you work with a certified treatment facility. This guide covers everything you need to know about ISPM-15 heat treatment, from the science behind the process to the practical steps for ensuring compliance.
The Science of Heat Treatment
Heat treatment works by raising the core temperature of the wood to a level that is lethal to all life stages of wood-boring insects, nematodes, and other organisms that pose phytosanitary risks. The ISPM-15 standard specifies that the wood must reach a core temperature of at least 56 degrees Celsius (132.8 degrees Fahrenheit) for a minimum of 30 continuous minutes.
This temperature-time combination has been scientifically validated to eliminate the target organisms while being achievable with standard industrial kiln equipment. The treatment is purely thermal; no chemicals are applied to the wood. After treatment and cooling, the wood retains its full structural properties and is safe to handle immediately.
Modern heat treatment facilities use temperature probes inserted into the thickest sections of the wood load to monitor core temperature in real time. The kiln is not released until the probes confirm that the minimum temperature has been sustained for the required duration. This instrumentation provides reliable, documented proof of treatment compliance.
The ISPM-15 Mark
Treated wood packaging must bear the official IPPC mark, which certifies compliance with ISPM-15. The mark includes four elements: the IPPC symbol (a stylized wheat sheaf), the two-letter country code (US for the United States), the unique registration number of the treatment provider, and the treatment code (HT for heat treatment, DH for dielectric heating, or MB for methyl bromide).
The mark must be applied by the certified treatment provider using a branding iron, stencil, or ink stamp. It must be legible, durable, and visible on at least two opposite sides of the packaging. Customs authorities in the importing country verify the mark as part of their phytosanitary inspection. Pallets without a legible ISPM-15 mark may be detained, quarantined, or refused entry.
What Requires Treatment
ISPM-15 applies to all wood packaging materials made from coniferous (softwood) and non-coniferous (hardwood) raw wood, including pallets, crates, boxes, dunnage, spools, and blocking used in international shipment. The regulation targets solid wood that could harbor pests, so it applies regardless of whether the wood is in direct contact with the shipped product.
Processed wood materials are exempt from treatment. This includes plywood, particle board, oriented strand board (OSB), veneer, and wood fiber products like MDF. The manufacturing processes for these materials involve temperatures and pressures that effectively eliminate pest risk. Pallets made entirely from plywood or OSB do not require ISPM-15 treatment, though they must still be free of bark.
Ensuring Compliance
The most reliable way to ensure ISPM-15 compliance is to source your export pallets from a certified treatment facility that stamps each pallet with the IPPC mark. Maintain records of your pallet purchases that link each order to the treatment provider's certification. When loading export shipments, verify that every pallet bears a legible ISPM-15 stamp before sealing the container.
Be especially careful with repaired pallets. If any component of a treated pallet is replaced with untreated wood, the pallet must be retreated and re-stamped by a certified facility. This is a common compliance gap that catches exporters by surprise. Establish a clear policy that export pallets are not repaired with uncertified components.
Fresno Pallets Heat Treatment Services
Fresno Pallets operates a certified ISPM-15 heat treatment facility serving exporters throughout the Central Valley. We can treat your existing pallets, supply pre-treated pallets from our inventory, or manufacture custom export pallets with treatment included. Our turnaround time is typically 24-48 hours, and we maintain detailed treatment records for traceability.
Whether you are shipping almonds to Europe, equipment to Asia, or produce to Canada, we ensure your wood packaging meets all international requirements. Contact Fresno Pallets to discuss your heat treatment needs and receive a quote.